Fat Fritz outmatches Stockfish (part 2)

by Elshan Moradiabadi
11/7/2019 – Yesterday we announced the results of an internal 100-game match pitting our new Fat Fritz engine against two versions of Stockfish. Today, further annotated highlights from Grandmaster ELSHAN MORADIABADI along with some of your feedback and questions. Stay tuned for more news next week on Fat Fritz that you won't want to miss!

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Next generation engine duels

Recapping part one: ChessBase recently staged two matches between Fat Fritz and Stockfish. The computer we used for both Fat Fritz and Stockfish was a Ryzen 7 3700X with an NVIDIA RTX 2080, 32 GB RAM. Ponder was switched off, the Silver Openings Suite was used to ensure maximum opening diversity, and the time control was 20m+10s.

Stockfish ran on 16 threads at 16 million nodes per second, while the pre-release version of Fat Fritz ran at a little over 11 thousand NPS (for the Leela specialists this was done with the slower CUDNN backend). The speed conditions are actually a good deal worse than AlphaZero, which had around a 900 to 1 NPS speed difference, while here Stockfish was running at 1450 times faster in NPS, so if anything, it favored Stockfish. 

We conducted matches against Stockfish 8 and Stockfish 10. Here are the results:

match results table

You'll find all games below.

Now, picking up on the commentary from GM Elshan Moradiabadi...


Where human intuition trains AI (part 2)

Having spoken about FF’s ability to play dynamic chess, let us see this pure demonstration of positional ideas, very similar to Leela in this regard, which distinguishes neural networks from other types of engines.

[Event "Rapid match 20m+10s"] [Site ""] [Date "2019.10.23"] [Round "5"] [White "Fat Fritz"] [Black "Stockfish 10 64 POPCNT"] [Result "1-0"] [ECO "A28"] [Annotator "Elshan"] [PlyCount "139"] [EventDate "2019.??.??"] [TimeControl "1200+10"] 1. c4 e5 2. Nc3 Nf6 3. Nf3 Nc6 4. e4 {0.17/13 25 The provided theory was already over a move ago, but FF amazes me by once again choosing the most fashionable line these days.} Bb4 {-0.30/33 62} 5. d3 {0.17/12 15} d6 {-0.20/ 30 18} 6. Be2 {0.16/12 35 This is also Magnus Carlsen's choice, though the general belief is that White should not let Black play a5.} a5 {-0.31/31 28 (0-0)} 7. O-O {0.15/12 56 (Le3)} O-O {-0.18/32 51} 8. h3 {0.13/12 11 (a3)} Bc5 {-0.44/32 53} 9. Be3 {0.11/14 40} Re8 {-0.39/29 19 (Sd4)} 10. Qd2 {0.13/11 31 (Sd5)} Bd7 {-0.43/31 13} 11. Bd1 {0.11/12 38 (Sd5)} h6 {-0.12/33 86} 12. Kh1 { 0.14/15 50 (Tc1)} Nh7 {-0.09/25 25 (Sd4)} 13. Nh2 {0.20/12 23} Rf8 {-0.11/30 64 } 14. Bg4 {0.21/13 41 (Tc1)} Nf6 {-0.15/28 14} 15. Bd1 {0.19/13 53 (Lxd7)} b6 { -0.15/33 151 (Lxe3)} 16. f4 {0.35/12 21 (Tc1)} Bxe3 {0.00/33 66} 17. Qxe3 { 0.33/14 16} Rb8 {0.00/34 34} 18. b3 {0.28/14 61 (fxe5)} Qe7 {-0.14/30 9} 19. f5 {0.27/13 7 (fxe5)} Nd4 {-0.37/30 15} 20. a4 {0.28/14 35 (Sd5)} c6 {-0.38/30 31 (Kh7)} 21. Nf3 {0.36/13 33} c5 {-0.27/32 17 (Sxf3)} 22. Ra2 {0.56/13 42 (Sh2)} Bc6 {0.00/39 56} 23. g4 {0.53/14 19} Nh7 {0.09/39 117} 24. Rh2 {0.50/13 26} Nxf3 {0.09/42 18 (g5)} 25. Bxf3 {0.60/16 52} Qh4 {0.09/44 14 (g5)} 26. Nd1 { 0.79/12 58 (Tg1)} Rbc8 {0.73/32 188 (Dg5)} 27. Be2 {0.94/11 29 (De2)} Rc7 { 0.97/32 60} 28. Rg1 {1.00/11 26 (Dg1)} g6 {0.88/28 11} 29. Qd2 {1.01/11 30} Kh8 {0.91/30 24 (Kg7)} 30. Ne3 {1.04/12 33} Qf6 {1.22/34 66 (Te8)} 31. h4 {1.13/16 32} g5 {1.12/39 43} 32. Nf1 {1.19/15 21} Qd8 {1.12/40 14 (gxh4)} 33. hxg5 { 1.25/14 39} Nxg5 {1.12/42 20 (hxg5)} 34. Rxh6+ {1.33/25 41} Kg7 {1.12/45 14 [#] This is a typical example of the advantage of AI (neural networks) over other brute force chess engines: intuition. I honestly don't know how they train themselves on it, but its resemblance to human intuition is astonishing. Here I had my computer run on this position and it only showed White's pseudo exchange-sac on depth 35. Needless to say, my engine couldn't detect the idea 3 or 4 moves in advance.} 35. Rxd6 $1 {1.41/28 22 Black is busted, the position is closed and white's extra space is the crucial factor here. It is the closest you can find human's intuition to AI.} Rh8+ {1.09/33 23} 36. Kg2 { 1.42/25 11} Qxd6 {1.75/34 22} 37. Qxg5+ {1.50/25 23} Kf8 {1.67/34 7} 38. f6 { 1.54/24 14} Ke8 {1.48/36 17} 39. Qg7 {1.55/22 0 (Th1)} Qf8 {1.72/36 12} 40. Qxf8+ {1.59/20 25 (Dg5)} Kxf8 {0.78/31 9} 41. Ne3 {1.60/21 0 (g5)} Rc8 { 2.21/41 73 (Ld7)} 42. g5 {1.58/17 88} Rg8 {2.23/36 39} 43. Kf3 {1.66/20 46 (Kf2)} Bd7 {2.24/31 7} 44. Nf5 {1.72/20 19} Rc6 {2.12/35 10} 45. Rg3 {1.79/20 42 (Kf2)} Bxf5 {2.12/33 4 (Th8)} 46. exf5 {2.46/18 62} Rd6 {2.87/37 13} 47. Ke4 {2.48/19 13} Rxf6 {2.96/39 15} 48. Kxe5 {2.50/17 17} Rc6 {2.92/40 7 (Th6)} 49. g6 {2.47/19 45} Ke7 {3.76/41 26 (Tc7)} 50. Bf3 {2.73/18 44} Rf6 {6.82/31 14} 51. Rh3 {2.74/19 10 (g7)} Rg7 {2.95/36 2} 52. gxf7 {2.76/17 17} Rgxf7 {2.97/40 6} 53. Rh5 {2.80/17 9} Rd6 {3.73/39 21 (Tf8)} 54. Bd5 {2.99/17 40} Rff6 { 4.21/32 11} 55. Rh7+ {3.02/16 12} Kd8 {4.58/32 10} 56. Rb7 {3.11/15 18 (d4)} Rh6 {2.83/36 3} 57. Be6 {3.12/15 13} Rxd3 {2.82/37 5} 58. Rxb6 {3.05/19 11} Kc7 {2.87/43 20} 59. Rb5 {2.90/17 30} Re3+ {3.07/41 9 (Kc6)} 60. Kd5 {3.38/12 40} Rexe6 {4.26/41 14 (Td3+)} 61. fxe6 {3.55/16 29} Rh5+ {5.37/40 10} 62. Ke4 { 3.42/16 0} Kd6 {5.86/39 10} 63. Rb6+ {3.68/14 16} Ke7 {6.35/35 11} 64. Ra6 { 3.71/13 9} Kf6 {6.37/36 10 (Tg5)} 65. Kd3 {3.97/12 20} Rg5 {7.38/32 10 (Ke7)} 66. Kc2 {3.91/11 35 (Kd2)} Rg2+ {5.28/26 3 (Th5)} 67. Kb1 {3.83/11 34} Rg5 { 8.77/35 17} 68. Kb2 {3.76/11 8 (Ka2)} Ke7 {9.39/32 10 (Tf5)} 69. Ka3 {3.83/11 11} Rh5 {10.49/35 10} 70. Rxa5 {3.43/11 10} 1-0

The following game is another breathtaking draw, which reminds a classical chess geek such as myself of the famous Kotov-Gligoric game from Zurich 1953. In this game FF offers not one but two positional exchange sacrifices, locking down White’s pieces and forcing Stockfish to return the sacrificed material seeking equality. This game is your assurance of working with a very creative engine whose intuition is trained at the highest level. If one ever suffered from skepticism over the accuracy of an engine then a game like this is like a life-time warranty, which assures one of the soundness of the engine’s judgement.

[Event "Rapid match 20m+10s"] [Site ""] [Date "2019.10.24"] [Round "12"] [White "Stockfish 10 64 POPCNT"] [Black "Fat Fritz"] [Result "1/2-1/2"] [ECO "A67"] [Annotator "Elshan"] [PlyCount "409"] [EventDate "2019.??.??"] [TimeControl "1200+10"] 1. d4 Nf6 2. c4 c5 3. d5 e6 4. Nc3 exd5 5. cxd5 d6 6. e4 g6 {Last book move.} 7. f4 {1.09/32 175} Bg7 {0.80/18 17} 8. Bb5+ {0.95/29 19} Nfd7 {0.81/20 18} 9. Bd3 {1.01/29 17 (a4)} Qh4+ {0.66/15 47 (0-0)} 10. g3 {0.98/29 17} Qd8 {0.66/18 13} 11. Nf3 {0.99/28 14} Na6 {0.66/17 60 (0-0)} 12. Nb5 {0.86/29 97 (0-0)} Nb6 {0.72/19 29} 13. f5 {0.80/29 15} O-O {0.83/21 69 (c4)} 14. O-O {1.00/28 13} c4 {0.84/20 0} 15. Bb1 {1.12/30 29 (Lc2)} Nd7 {0.24/17 40} 16. Kh1 {0.81/30 37 (Le3)} Qb6 {0.13/19 35} 17. a4 {0.98/30 24} Nac5 {0.11/19 17} 18. Bc2 {0.70/33 123 (Lf4)} a6 {0.06/20 42} 19. Nc3 {0.80/28 11} Qc7 {0.05/24 21 (Db4)} 20. g4 { 0.57/31 99 (Lf4)} Rb8 {-0.13/18 47} 21. a5 {0.12/31 72 [#] Unlike Leela, Fat Fritz has a sweet tooth for complexity, and while Leela deals with positional sacrifices as they happen (as a matter of necessity or not), Fat Fritz actively seeks complex lines, making it a great companion for those who take a liking to the games of Kasparov and Tal!} b6 {-0.16/20 28 weakening c6,} 22. Nd4 {0.43/25 17 (De1)} b5 {-0.26/22 54 Couldn't you do it earlier?!} 23. Nc6 { 0.69/27 16 [#]} b4 $3 {-0.25/31 31 The two exclamation points is for the aesthetic essence of the idea and not its soundness, though the idea is one of the three sound ones in this position.} 24. Nxb8 {0.00/35 79 (Sa4)} Qxb8 { -0.37/22 39} 25. Na4 {0.00/36 17} b3 {-0.38/23 20} 26. Bb1 {0.00/35 14} Nxa4 { -0.35/24 23} 27. Rxa4 {0.00/35 18} Qb5 {-0.35/26 0} 28. Ra3 {0.00/37 19 (Ta1)} Be5 {-0.47/17 63 White's attack and position is completely blocked.} 29. Qe2 { 0.15/28 23} Nc5 $5 {-0.47/18 0 Direct and aggressive.} 30. Bh6 {0.00/32 92 (Tf2)} Bd7 $5 {-0.29/32 86 [#] The second exchange sacrifice! I heard Fat Fritz had gone through all of the games on Mega Database, I am sure it took a close look at Kotov-Gligoric Zurich 1953.} 31. Bxf8 {0.00/36 15 (Tc1)} Kxf8 { -0.31/27 63} 32. Rc1 {0.00/39 17} Qb7 {-0.26/32 25} 33. Rxc4 $1 {0.00/40 22 Stockfish realizes the dire situation and gives back material for activity.} Bb5 {-0.23/31 18} 34. Bd3 {0.00/42 17} Bxc4 {-0.23/27 0} 35. Bxc4 {0.00/43 39} Qb4 {-0.23/26 0} 36. Ra1 {0.00/45 14} g5 $1 {-0.23/25 44 JIT: Just-in-time!} 37. Kg2 {0.00/36 41 (h4)} h6 {-0.46/22 120 [#] (Sa4) The position is dynamically balanced and the two giant engines concede to this fact after a hard-fought battle.} 38. h3 {0.00/38 52 (Tf1)} Kg8 {-0.90/19 61 (Ke7)} 39. Rf1 {0.00/37 16 (f6)} Bxb2 {-0.84/21 37 (Dxa5)} 40. Rb1 {0.00/40 13} Be5 {-0.81/19 23 (Ld4)} 41. Bxb3 {0.00/45 17} Qxa5 {-0.78/19 27 (Dc3)} 42. Qe3 {0.00/43 12} Qa3 {-0.76/21 108} 43. Qf3 {0.00/45 13} Qb4 {-0.77/17 0} 44. Bc2 {0.00/41 22} Qc4 {-0.76/23 10 (Dd2+)} 45. Rb8+ {0.00/45 15 (Lb3)} Kg7 {-0.89/17 45} 46. Bb1 {0.00/45 12} Nd7 {-0.85/18 62 (Kf6)} 47. Rb7 {0.00/42 16} Qc8 {-0.85/16 0 (Sc5) } 48. Rb3 {0.00/40 12} a5 {-0.84/17 21 (Sc5)} 49. Qe3 {0.00/41 14 (Dd1)} Nc5 { -0.90/16 73 (Kf6)} 50. Rb5 {0.00/39 15} Qa6 {-0.82/20 30} 51. Qe2 {0.00/44 12 (Txc5)} a4 {-0.77/15 26} 52. Qc4 {0.00/45 18} Qa7 {-0.75/21 7} 53. Ba2 { 0.00/41 11 (Db4)} Nd7 {-1.27/12 22} 54. Qd3 {0.00/42 29} Nf6 {-1.26/13 22} 55. Rb4 {0.00/45 11} Nd7 {-1.24/13 8} 56. Bc4 {0.00/42 12 (Tb5)} a3 {-1.38/13 23} 57. Ba2 {0.00/46 13} Qa5 {-1.35/13 31 (Dc5)} 58. Qb5 {0.00/45 15} Qa7 {-1.34/ 13 3 (Dc7)} 59. Qd3 {0.00/45 13 (De2)} Bb2 {-1.33/12 26 (Dc5)} 60. Qd2 { 0.00/41 11} Qa6 {-1.29/13 29} 61. Bb1 {0.00/40 11 (Lc4)} Be5 {-1.29/10 9 (Sc5)} 62. Qc2 {0.00/42 12 (La2)} Qa7 {-1.41/12 11} 63. Ba2 {0.00/46 25 (Db3)} Qa5 { -1.34/12 22 (De3)} 64. Qd2 {0.00/44 8 (Dc4)} Ba1 {-1.30/10 12 (Sc5)} 65. Rb2 { 0.00/42 12} Qc5 {-1.24/12 13 (Da6)} 66. Rb3 {0.00/42 13 (Tc2)} Be5 {-1.12/13 14 (Lb2)} 67. Bb1 {0.00/41 21} Bb2 {-0.81/17 10 (Sf6)} 68. h4 {0.00/40 15 (Tb7) } Bf6 {-0.99/19 6 (Kf6)} 69. hxg5 {0.00/42 12} hxg5 {-0.91/21 6} 70. Rb7 { 0.00/40 12 (De3)} Ne5 {-1.06/15 13} 71. Rb3 {0.00/43 11} Nd7 {-0.99/21 5 (Sxg4) } 72. Ba2 {0.00/46 17 (De3)} Ne5 {-1.11/14 13 (Dc4)} 73. Qc3 {0.00/37 8} Nc4 { -1.05/15 6} 74. Qd3 {0.00/38 10} Be5 {-0.74/18 31 (Lb2)} 75. Bb1 {0.00/41 10} Bf6 {-0.65/21 1} 76. Ba2 {0.00/41 11} Bd4 {-0.57/19 11 (Se5)} 77. Bb1 {0.00/42 10} Ne5 {-0.54/22 8 (Lf6)} 78. Qd2 {0.00/42 9} Kf6 {-0.53/21 5} 79. Qb4 { 0.00/44 11} Qxb4 {-0.52/20 4} 80. Rxb4 {0.00/47 15} Bc5 {-0.52/17 7} 81. Rb8 { 0.00/46 12 (Ta4)} Nxg4 {-0.57/12 16} 82. Re8 {0.00/44 10} Ne5 {-0.53/12 22} 83. Ba2 {0.00/47 21 (Kg3)} Nd7 {-0.52/11 19 (Le3)} 84. Kg3 {0.00/47 23} Ne5 { -0.49/11 10} 85. Bb1 {0.00/44 24 (Ta8)} Bb4 {-0.49/10 10 (Sc4)} 86. Ba2 { 0.00/42 6 (Ta8)} Be1+ {-0.51/10 7} 87. Kg2 {0.00/48 8} Bd2 {-0.50/11 14 (Lb4)} 88. Rd8 {0.00/48 8 (Ta8)} Bb4 {-0.50/11 5} 89. Ra8 {0.00/49 11 (Tb8)} Nd3 { -0.47/10 15 (Lc5)} 90. Bb1 {0.00/45 15 (Kg3)} Ne5 {-0.47/11 10} 91. Ba2 { 0.00/48 9 (Kg3)} Bc5 {-0.45/10 8} 92. Kg3 {0.00/48 53} Kg7 {-0.42/10 10 (Lb4)} 93. Bb3 {0.00/47 5 (Lb1)} Kh6 {-0.42/10 12 (Kf6)} 94. Bd1 {0.00/44 7 (Tg8)} Kh7 {-0.45/9 9 (Sd7)} 95. Bh5 {0.00/46 7 (Lc2)} Kg7 {-0.42/11 9} 96. Be2 {0.00/50 10} Kh7 {-0.39/11 11 (Sd7)} 97. Kh3 {0.00/50 9 (Ld1)} Kh6 {-0.41/10 8 (Kg7)} 98. Kg3 {0.00/51 8} Kg7 {-0.38/11 11} 99. Ra6 {0.00/52 12 (Lb5)} Kf6 {-0.41/10 12} 100. Kh3 {0.00/48 11 (Ta4)} Ke7 {-0.43/11 9} 101. Kg2 {0.00/52 9 (Lb5)} Bb4 {-0.47/11 12 (Kf6)} 102. Ra8 {0.00/50 18 (Lb5)} Bc5 {-0.42/12 10 (Kf6)} 103. Kg3 {0.00/49 7} Bb4 {-0.33/13 9 (Kf6)} 104. Bh5 {0.00/42 8 (Ta4)} Nd7 {-0.41/ 12 10 (Kf6)} 105. Ra4 {0.00/45 10} Bc5 {-0.38/14 3} 106. Be2 {0.00/54 28} Nb6 { -0.35/13 9 (Se5)} 107. Ra6 {0.00/51 6} Nd7 {-0.33/13 6} 108. Kg4 {0.00/51 11 (Ta4)} f6 {-0.39/14 11 (Kf6)} 109. Bb5 {0.31/48 7} Ne5+ {-0.34/15 6} 110. Kg3 { 0.31/52 7 (Kh5)} Kd8 {-0.40/11 11} 111. Bf1 {0.31/50 8 (Ta4)} Kc7 {-0.37/11 24} 112. Be2 {0.31/51 7 (Ta4)} Kb7 {-0.37/10 10 (Kd8)} 113. Kh2 {0.31/43 7 (Ta4)} Kc8 {-0.42/10 9 (Kc7)} 114. Kg3 {0.30/53 47} Kc7 {-0.37/9 11 (Kd8)} 115. Bf1 { 0.30/50 10 (Ta4)} Nd7 {-0.36/10 10 (Kd7)} 116. Bc4 {0.29/46 6 (Lb5)} Kb7 { -0.37/10 10 (Se5)} 117. Bb5 {0.29/51 8} Ne5 {-0.37/10 4} 118. Bf1 {0.28/48 16 (Le2)} Kb8 {-0.36/10 16 (Kc7)} 119. Ra5 {0.21/51 6 (Lb5)} Kc8 {-0.37/9 9 (Kb7)} 120. Be2 {0.20/53 6 (Ta4)} Nd7 {-0.37/9 11 (Kc7)} 121. Bb5 {0.20/48 13 (Ta4)} Ne5 {-0.34/10 4} 122. Bf1 {0.20/54 8 (Le2)} Nd7 {-0.38/9 16 (Kc7)} 123. Ra8+ { 0.11/45 9 (Lb5)} Kc7 {-0.37/11 8 (Kb7)} 124. Bb5 {0.01/49 24 (Ta4)} Ne5 { -0.36/11 5} 125. Bf1 {0.01/53 7 (Le2)} Kb6 {-0.31/10 16 (Lb4)} 126. Ra6+ { 0.00/52 9 (Ta4)} Kb7 {-0.29/10 7 (Kc7)} 127. Be2 {0.00/46 31 (Ta4)} Kc8 { -0.30/10 13 (Kc7)} 128. Bd1 {0.00/50 5 (Ta4)} Nd7 {-0.37/11 12 (Kc7)} 129. Bb3 {0.00/50 11 (Le2)} Ne5 {-0.41/10 10 (Kb7)} 130. Ra8+ {0.00/43 5 (Ld1)} Kc7 { -0.39/13 5} 131. Ba2 {0.00/47 9 (Tf8)} Nd7 {-0.36/10 9 (Sd3)} 132. Rh8 { 0.00/41 10 (Te8)} Be3 {-0.33/10 16 (Ld4)} 133. Kf3 {0.00/43 6 (Ta8)} Bc1 { -0.40/10 7} 134. Ra8 {0.00/44 7 (Th7)} Nc5 {-0.45/12 7 (Kb7)} 135. Bc4 { 0.00/42 13} Kb7 {-0.44/14 6 (Lb2)} 136. Ra5 {0.00/42 5} Nd7 {-0.43/13 5} 137. Rb5+ {0.00/41 10} Ka7 {-0.42/12 16 (Kc7)} 138. Ke2 {0.00/42 6 (Ta5+)} Ne5 { -0.48/12 14 (Lb2)} 139. Ba2 {0.00/44 7} Bb2 {-0.43/13 12 (Sd7)} 140. Kd2 { 0.00/42 8 (Ke3)} Nd7 {-0.52/11 9} 141. Ke3 {0.00/44 8 (Ke2)} Bc3 {-0.50/11 13 (Lc1+)} 142. Rb3 {0.00/45 6 (Lb1)} Bb2 {-0.61/12 5} 143. Rb5 {0.00/50 12 (Tb4)} Ne5 {-0.39/11 15 (Lc1+)} 144. Rb4 {0.00/44 7 (Ke2)} Nf7 {-0.36/11 11 (Sd7)} 145. Bc4 {0.00/42 14 (Tb5)} Ka8 {-0.30/12 10 (Se5)} 146. Kd3 {0.00/43 13 (Le2)} Ne5+ {-0.16/14 9} 147. Kc2 {0.00/46 8} g4 {-0.11/15 6} 148. Kb1 {0.00/44 20 (Lf1)} g3 {-0.23/18 7} 149. Bf1 {0.00/46 8} Nf3 {-0.15/20 5} 150. Bh3 {0.00/43 14} Ka7 {-0.10/21 11} 151. Ka2 {0.00/46 6} Ng1 {-0.07/21 20} 152. Bf1 {0.00/45 13} Nf3 {-0.08/22 0} 153. Bh3 {0.00/46 15} Ne1 {-0.05/19 6 (Sg1)} 154. Rb3 { 0.80/35 5} Be5 {-0.03/21 3 (g2)} 155. Rxa3+ {0.84/36 6} Kb6 {0.03/20 7} 156. Re3 {0.84/43 7} Nc2 {0.06/19 5} 157. Rb3+ {0.83/45 13} Kc5 {0.08/18 6} 158. Kb1 {0.83/49 9} Nd4 {0.09/17 6} 159. Rc3+ {0.82/48 12 (Td3)} Kb4 {0.06/14 24} 160. Rd3 {0.82/49 6} Kc4 {0.10/14 13 (Sb5)} 161. Re3 {1.09/46 5} Nb5 {0.16/15 29 (Kc5)} 162. Kc2 {1.07/45 7} Nd4+ {0.15/13 0} 163. Kd1 {1.00/50 9} Kb5 {0.16/13 15 (Lf4)} 164. Ra3 {1.00/45 6 (Lf1+)} Kb4 {0.19/12 9} 165. Ra2 {1.00/47 7 (Ta8) } Kc3 {0.16/10 15} 166. Bf1 {1.00/51 8} Nb3 {0.19/11 6} 167. Ra8 {1.00/52 12 (Ta3)} Nc5 {0.17/10 11 (Kd4)} 168. Bg2 {1.00/49 7 (Ke2)} Nb3 {0.15/10 9} 169. Bf1 {1.00/55 8 (Ta3)} Nc5 {0.16/10 11 (Kd4)} 170. Bg2 {1.00/52 8 (Ke2)} Nb3 { 0.13/9 9} 171. Ra4 {1.00/54 7 (Ta3)} Kd3 {0.14/10 16} 172. Ke1 {1.00/52 12 (Ta3)} Nd4 {0.05/10 7 (Lc3+)} 173. Ra3+ {1.00/45 7} Kc2 {0.07/11 8} 174. Bf1 { 1.00/50 7} Bf4 {0.14/11 11 (Sb3)} 175. Ra2+ {1.00/47 9} Kc3 {0.18/11 13 (Kc1)} 176. Kd1 {1.00/47 8 (Ta8)} Be5 {0.16/10 8} 177. Ra4 {1.00/55 9 (Ta8)} Nb3 { 0.15/10 12} 178. Rc4+ {1.00/56 12} Kb2 {0.19/10 0} 179. Rc2+ {1.00/60 21 (Tc8)} Ka3 {0.22/10 13} 180. Rc6 {1.00/50 15 (Tc8)} Nc5 {0.16/9 16 (Kb2)} 181. Kc2 { 1.27/43 4 (Tb6)} Kb4 {0.19/10 15 (Sxe4)} 182. Rc8 {1.58/43 6} Ka5 {0.20/9 10} 183. Bg2 {1.58/46 8 (Tb8)} Kb4 {0.17/8 10} 184. Bf1 {1.58/44 7 (Kd2)} Ka5 { 0.18/9 10} 185. Ra8+ {1.29/45 58 (Tb8)} Kb6 {0.18/9 10} 186. Bd3 {1.14/45 13 (Tb8+)} Kb7 {0.12/9 8} 187. Rg8 {1.14/45 8} Kb6 {0.15/9 9 (Kc7)} 188. Rg7 { 1.14/41 5 (Lf1)} Ka5 {0.12/9 10 (Lf4)} 189. Rc7 {1.14/45 6 (Lf1)} Kb6 {0.10/9 9 } 190. Rg7 {1.14/46 6} Ka5 {0.11/9 11} 191. Rg4 {1.14/46 8 (Lf1)} Kb4 {0.09/9 13 (Kb6)} 192. Rg8 {1.14/44 10 (Lf1)} Ka4 {0.11/9 10 (Sd7)} 193. Rc8 {1.13/47 36 (Lf1)} Kb4 {0.11/9 10} 194. Rf8 {1.05/49 13 (Ta8)} Ka5 {0.11/9 11 (Ka3)} 195. Rb8 {1.05/42 4} Nd7 {0.11/10 8 (Lf4)} 196. Rb1 {1.05/40 5} Nc5 {0.12/10 5 (Lf4)} 197. Kd2 {1.05/43 9} Ka4 {0.12/10 9 (Lf4+)} 198. Bb5+ {1.04/45 11 (Ke3)} Ka3 {0.11/10 14 (Ka5)} 199. Kc2 {1.04/48 4} Ka2 {0.10/11 6 (Ld4)} 200. Be2 { 1.04/49 7 (Lf1)} Ka3 {0.08/9 8} 201. Rb8 {1.00/48 14} Ka4 {0.05/9 9 (Sxe4)} 202. Bf1 {1.00/45 4} Ka5 {0.04/7 19 (Lf4)} 203. Bc4 {0.00/58 29 (Tb1)} Nd7 { 0.00/5 11} 204. Ra8+ {0.00/78 7 (Tb1)} Kb4 {0.00/2 12} 205. Bf1 {0.00/127 0 Draw agreed.} 1/2-1/2

Earlier in this article, I commented on FF’s technical play and its approach. Most of the time engines become very similar when the endgame is reached, as they all use tablebases. However, even in such cases, FF tries its best to solve difficult endings, remaining faithful to active ides and the concept of domination. Its preference for prophylactic play is a feature I personally cherish most, though one should be careful learning these paths as they may not be the most feasible solutions for over the board games. Still, let us look at the following game, where FF handles a slightly worse position in a very unconventional but principled way.

[Event "Rapid match 20m+10s"] [Site ""] [Date "2019.10.24"] [Round "13"] [White "Fat Fritz"] [Black "Stockfish 10 64 POPCNT"] [Result "1/2-1/2"] [ECO "A87"] [Annotator "Elshan"] [PlyCount "145"] [EventDate "2019.??.??"] [TimeControl "1200+10"] 1. d4 f5 2. g3 Nf6 3. Bg2 g6 4. Nf3 Bg7 5. O-O O-O 6. c4 d6 7. Nc3 Qe8 8. d5 { Last book move.} Na6 {0.25/31 95} 9. Be3 {0.69/13 31} Bd7 {0.17/31 51} 10. Rb1 {0.73/13 20 (Tc1)} c5 {0.37/30 47 (c6)} 11. Qd2 {0.75/18 26} Nc7 {0.44/31 19} 12. b4 {0.72/18 34} cxb4 {0.32/32 17} 13. Rxb4 {0.73/19 13} b6 {0.59/36 107} 14. h3 {0.72/18 58 (Tb3)} Na6 {0.27/31 20 (Dc8)} 15. Rb3 {0.71/19 30} Qc8 { 0.44/32 22} 16. Nd4 {0.67/22 87} Nc5 {0.22/32 45 (Dxc4)} 17. Ra3 {0.86/18 22} Nfe4 {0.30/36 57 (Sce4)} 18. Nxe4 {0.90/17 32} Nxe4 {0.40/35 16} 19. Qd3 { 0.87/20 58 (Dc2)} Nc5 {0.33/36 20} 20. Qd1 {0.94/13 38 (Dd2)} Ne4 {0.33/36 26 (Lf6)} 21. Qd3 {0.89/18 35 (Dc2)} Nc5 {0.35/37 19} 22. Qd2 {0.88/23 24} Ne4 { 0.46/36 34} 23. Qc2 {0.83/24 15} b5 {0.43/36 22} 24. Bxe4 {0.81/24 23} Bxd4 { 0.42/35 17} 25. Bxd4 {0.81/24 20} fxe4 {0.48/37 65} 26. g4 {0.78/27 69 (Te3)} Qxc4 {0.14/33 20} 27. Qxe4 {0.77/31 0} b4 {0.48/35 45} 28. Rd3 {0.76/29 18} Rae8 {0.25/33 14} 29. Rd2 {0.75/27 23} e5 {0.26/38 98} 30. dxe6 {0.73/26 22} Rxe6 {0.26/36 13} 31. Qb7 {0.73/26 30} Rf7 {0.62/37 115 (Te7)} 32. Qb8+ { 1.07/19 92} Bc8 {0.33/34 13 (Te8)} 33. Bxa7 {0.67/21 125 (Le3)} Rb7 {0.00/38 13 (h5)} 34. Qa8 {0.24/19 32} d5 {0.00/43 19} 35. Rdd1 {0.15/21 27} Ra6 { 0.00/43 33} 36. Rc1 {0.14/20 16} Rbxa7 {0.00/41 28} 37. Qxc8+ {0.13/18 15} Qxc8 {0.00/45 28} 38. Rxc8+ {0.14/17 15} Kg7 {0.00/45 22} 39. Rb8 {0.13/16 141 (Tb1) } Rxa2 {0.00/42 16} 40. e3 {0.13/14 0} Rb2 {0.00/43 43 (d4)} 41. Kg2 {0.18/11 54 (Tb5)} Kf6 {0.00/40 24 (Td7)} 42. Kg3 {0.17/13 69} Rf7 {0.00/41 18} 43. Rd1 {0.17/14 8 (Tb6+)} Kg7 {0.00/41 15} 44. Rf1 {0.16/13 18} Rb3 {0.00/42 35} ( 44... Rd7 45. Rb5 d4 46. exd4 Rxd4 47. Rb7+ Kf6) 45. Kg2 {0.16/13 38 [#] Here is another difference between FF to any other engine or human way of thinking: It has a great interest in fortresses. Like the previous game, it creates a situation making it impossible for White to improve. By contrast, GMs would try to activate the king and trade the d-pawn for the e-pawn and hold a 2-3 endgame.} h5 {0.00/43 29} (45... Rd7 46. Rb5 d4 47. exd4 Rxd4) 46. Rb5 { 0.16/13 42 (Td1)} h4 $1 {0.00/40 23 (d4)} 47. Rxd5 {0.25/12 26} Rb2 {0.00/43 20 Now white is tied down.} 48. Rb5 {0.23/12 36 (Td4)} Kh6 {0.00/39 14 (b3)} 49. Rb8 {0.23/11 52 (Tb6)} Re7 {0.00/46 39 (b3)} 50. Re1 {0.26/11 24 (Kf3)} Rf7 {0.00/45 17} 51. Rf1 {0.19/13 9} b3 {0.00/46 10 (Te7)} 52. Rb5 {0.23/11 37} Kg7 {0.00/46 11} 53. Rb6 {0.22/11 22 (g5)} Kf8 {0.00/42 11 (Kh6)} 54. e4 {0.24/11 19 (g5)} Rf4 {0.00/37 12 (Kg7)} 55. e5 {0.19/12 18 (Kg1)} Ke7 {0.00/39 13 (g5)} 56. Kg1 {0.24/13 14} Kd7 {0.00/41 17 (Te4)} 57. e6+ {0.20/15 19 (Td1+)} Kc7 { 0.00/43 15} 58. Rb5 {0.14/16 19} Kd6 {0.00/41 16} 59. Rb6+ {0.12/15 13} Kc7 { 0.00/44 20} 60. Re1 {0.10/14 27 (e7)} Rfxf2 {0.00/46 9} 61. e7 {0.08/12 16} Rg2+ {0.00/45 24} 62. Kh1 {0.07/9 0} Rh2+ {0.00/46 19} 63. Kg1 {0.05/7 0} Rbg2+ {0.00/50 70 (Thg2+)} 64. Kf1 {0.12/13 0} Rf2+ {0.00/53 19 (Tb2)} 65. Kg1 { 0.13/10 0} Rfg2+ {0.00/47 17} 66. Kf1 {0.08/7 0} Rf2+ {0.00/50 20 (Td2)} 67. Kg1 {0.13/6 0} Rhg2+ {0.00/49 59} 68. Kh1 {0.08/6 0} Kxb6 {0.00/57 48 (Th2+)} 69. e8=Q {0.03/9 85} Rh2+ {0.00/58 5} 70. Kg1 {0.02/7 0} Rhg2+ {0.00/66 11} 71. Kh1 {0.01/5 0} Rh2+ {0.00/64 29} 72. Kg1 {0.00/3 0} Rhg2+ {0.00/67 8} 73. Kh1 { 0.00/2 0 Remis angenommen} 1/2-1/2

A fast learner!

The following game is another example that demonstrates how well Fat Fritz understands pawn structures. In this dodgy line of the Alekhine, Fat Fritz outplays Stockfish 10 in a very classy manner.

[Event "Rapid match 20m+10s"] [Site ""] [Date "2019.10.24"] [Round "19"] [White "Fat Fritz"] [Black "Stockfish 10 64 POPCNT"] [Result "1-0"] [ECO "B04"] [Annotator "Elshan"] [PlyCount "145"] [EventDate "2019.??.??"] [TimeControl "1200+10"] 1. e4 Nf6 2. e5 Nd5 3. d4 d6 4. Nf3 {Last book move.} g6 {0.31/33 114} 5. Bc4 { 0.77/17 23} Nb6 {0.26/28 9} 6. Bb3 {0.77/17 13} Bg7 {0.23/30 20 (a5)} 7. Ng5 { 0.77/24 26 (De2)} e6 {0.10/29 20} 8. Qf3 {0.75/24 19} O-O {0.45/34 87 (De7)} 9. Qh3 {0.61/20 43} h6 {0.24/30 8} 10. Ne4 {0.55/20 77 (Sf3)} d5 {0.24/31 19} 11. Nc5 {0.55/17 0} Kh7 {0.24/32 24} 12. Be3 {0.58/17 40 (c3)} N8d7 {0.23/32 75} 13. Nxd7 {0.59/18 15} Bxd7 {0.20/31 11} 14. Nd2 {0.61/16 19} Na4 {0.22/35 42 (f5)} (14... c5) 15. O-O-O {0.70/17 53 (Tb1)} b6 {0.19/29 58 (b5)} (15... c5 16. Bxa4 Bxa4 17. dxc5 Qa5 18. Kb1 b6) 16. g4 {1.11/16 49 (Kb1)} c5 {0.15/27 11 } 17. Rhg1 {1.13/19 20 (c3)} Rh8 {0.50/32 69} 18. f4 {1.15/18 21} Qc7 {0.49/29 14 (Tc8)} 19. c3 {1.10/22 47} b5 {0.16/30 20} 20. Kb1 {1.11/21 23 (dxc5)} c4 { -0.09/28 11 (Tab8)} 21. Bxa4 {1.17/17 51} bxa4 {0.21/31 41} 22. a3 {1.19/15 19} Rab8 {0.58/33 133 (Thb8)} 23. Ka1 {1.37/12 51} Rb7 {0.59/35 12 (Tb6)} 24. Nb1 { 1.50/11 48 (Tb1)} Kg8 {1.07/32 87 (Db6)} 25. Qg2 {1.51/13 44} Kf8 {1.26/38 106} 26. Rdf1 {1.52/14 29} Qc8 {1.17/40 77 (Ke8)} 27. h4 {1.75/19 43} h5 {2.01/34 44 } 28. f5 {1.78/20 18} exf5 {1.90/32 10} 29. gxf5 {1.81/19 14} Bxf5 {1.86/36 12} 30. Qxd5 {1.83/18 15} Rd7 {2.08/36 24 (Ld3)} 31. Qg2 {2.16/15 67} Rc7 {2.44/37 67} 32. Nd2 {2.16/15 41} Kg8 {2.27/36 48 (Ld3)} 33. Rf4 {2.16/14 58 (Tf2)} Kh7 {2.11/30 8} 34. Ne4 {2.13/15 65} Bxe4 {2.16/36 14} 35. Qxe4 {2.12/14 0} Re8 { 2.15/38 26 (Db7)} 36. Rgf1 {2.09/11 80 (Tg5)} Kg8 {1.61/35 13 (De6)} 37. R4f2 { 2.05/11 51 (Dc2)} Qb7 {1.59/35 37} 38. Qc2 {2.02/11 16} Qc6 {1.58/37 7} 39. Qc1 {2.02/11 35} Rd7 {1.73/41 65 (De4)} 40. Bh6 {2.08/12 27} Bh8 {1.73/41 9 (De4)} 41. Rg1 {2.13/10 46} Qd5 {1.73/42 10 (Tb7)} 42. Qc2 {2.14/10 28} Kh7 {1.73/43 10} 43. Bc1 {2.05/11 37} Bg7 {1.73/45 13} 44. Qxa4 {2.03/11 24} Re6 {1.73/45 12 } 45. Qc2 {2.02/14 16 (Lg5)} Rb7 {1.73/42 13} 46. Re2 {2.06/14 21 (Tgf1)} Kh8 { 1.73/40 21 (Lf8)} 47. Qe4 {2.12/10 44 (Teg2)} Qxe4 {2.02/36 29 (Db5)} 48. Rxe4 {2.40/12 22} Kh7 {2.19/35 15} 49. Bf4 {2.45/14 17 (Ka2)} Rd7 {1.69/28 7} 50. Ka2 {2.54/14 19 (Kb1)} f6 {1.87/33 19} 51. Rge1 {2.58/14 11} fxe5 {1.97/33 28} 52. dxe5 {2.64/13 27 (Lg3)} Rc7 {2.02/31 9} 53. Rd1 {2.65/12 11 (Lg3)} Bf8 { 2.73/32 58} 54. Rdd4 {2.70/15 29} Be7 {2.89/31 23} 55. Bh2 {2.76/16 19} g5 { 2.71/31 12} 56. hxg5 {2.78/15 12} Bxg5 {3.08/30 23} 57. Rxc4 {2.87/14 21} Rxc4 {3.20/27 10} 58. Rxc4 {2.84/13 10} Kg6 {3.40/28 13} 59. b4 {2.87/12 15} Kf5 { 3.50/27 10 (h4)} 60. Kb3 {3.17/11 31} Rg6 {3.68/26 10 (h4)} 61. Rd4 {3.45/10 30 (Tc7)} Be7 {3.90/24 10} 62. Rd2 {3.57/10 16} Bh4 {4.18/27 10 (h4)} 63. a4 { 3.91/9 28} Be1 {4.49/27 10 (Le7)} 64. Re2 {5.56/9 12 (Td1)} Bh4 {4.50/30 3} 65. a5 {4.67/9 23 (Td2)} Ke6 {4.71/28 17 (Le7)} 66. a6 {4.76/8 12 (Td2)} Rg7 { 5.23/26 10 (Le7)} 67. c4 {4.72/8 16 (b5)} Rd7 {5.78/24 10 (Tg4)} 68. c5 { 5.72/7 10 (Tg2)} Be7 {7.03/26 10 (Td4)} 69. Kc4 {6.96/7 9 (Tc2)} Rd1 {6.12/23 2 } 70. Kb5 {5.88/8 14 (Tc2)} h4 {7.19/27 18 (Tb1)} 71. Rb2 {5.41/8 8 (Tg2)} Bd8 {7.53/27 10 (Ta1)} 72. Kc6 {6.23/7 10} Rd7 {8.25/25 10 (Le7)} 73. Rg2 {7.20/8 12} 1-0

On the flipside, when facing the same system FF quickly realizes the threat of closing the position and Black’s problem with the lack of space. It opts for a slightly worse position, but holds the game in style. Here is the game, without notes, just to illustrate the difference in approach.

[Event "Rapid match 20m+10s"] [Site ""] [Date "2019.10.24"] [Round "20"] [White "Stockfish 10 64 POPCNT"] [Black "Fat Fritz"] [Result "1/2-1/2"] [ECO "B04"] [Annotator "Elshan"] [PlyCount "289"] [EventDate "2019.??.??"] [TimeControl "1200+10"] 1. e4 Nf6 2. e5 Nd5 3. d4 d6 4. Nf3 {Last book move.} dxe5 {0.54/15 16} 5. Nxe5 {1.00/31 64 (c4)} c6 {0.52/14 31} 6. Be2 {1.05/29 17 (Sf3)} Bf5 {0.55/15 25 (Sd7)} 7. O-O {0.97/28 27} Nd7 {0.55/16 19} 8. Nf3 {0.95/33 43} e6 {0.54/15 26 (h6)} 9. c4 {1.03/30 13} N5f6 {0.54/14 12} 10. Nh4 {0.84/35 136} Bg6 {0.53/14 37 (Lxb1)} 11. Nc3 {0.85/29 73} Bd6 {0.54/14 37} 12. f4 {0.89/29 43 (c5)} Ne4 { 0.29/14 54 (Lf5)} 13. Nxg6 {1.01/28 9 (g3)} Nxc3 {0.22/13 38} 14. bxc3 { 0.91/29 19} hxg6 {0.21/12 14} 15. g3 {0.91/31 28} O-O {0.21/11 47 (Da5)} 16. Be3 {0.98/30 29 (a4)} c5 {0.13/10 50 (b6)} 17. Qd3 {0.85/30 42} Qc7 {0.15/11 75 (Tc8)} 18. Bf2 {0.95/31 16 (a4)} Rfd8 {0.18/10 46 (Tac8)} 19. Qf3 {1.02/31 42} b6 {0.23/10 32 (Tac8)} 20. a4 {0.89/32 61} Rac8 {0.20/12 21} 21. Kg2 { 0.85/32 12 (Tfb1)} f5 {0.24/11 30 (Le7)} 22. Bd3 {0.67/33 88 (Tab1)} cxd4 { 0.23/14 39 (Sf6)} 23. cxd4 {0.69/30 16} Bb4 {0.22/19 9} 24. Rfc1 {0.79/34 103 (Tab1)} Nf6 {0.06/11 43} 25. Rc2 {0.69/32 31} Kh7 {0.05/17 62 (Dd7)} 26. Rb1 { 0.68/31 43} a5 {0.05/23 9} 27. Rbc1 {0.68/34 48 (c5)} Qd7 {0.05/14 40} 28. Re2 {0.68/35 10} Ng4 {0.10/15 28 (Te8)} 29. Bg1 {0.82/28 11} Nf6 {0.10/14 11} 30. Bf2 {0.68/35 62 (h3)} Ng4 {0.06/14 60 (Te8)} 31. Bg1 {0.55/31 19} Nf6 {0.08/15 14} 32. Kh1 {0.68/34 65} Qxa4 {0.00/18 41 (Tc7)} 33. Rxe6 {0.00/33 25} Rd6 { 0.00/23 0 (b5)} 34. Rxd6 {0.31/31 26 (Te5)} Bxd6 {-0.04/24 56} 35. Qf1 { 0.39/35 38} Ba3 {-0.04/30 27 (Dc6+)} 36. Ra1 {0.94/28 11 (Tb1)} Qb4 {-0.04/18 91 (Dc6+)} 37. Rb1 {0.13/33 62} Qc3 {-0.04/24 0 (Dd6)} 38. Rxb6 {0.00/35 27} Re8 {-0.04/21 0} 39. Be2 {0.00/38 9} Bc1 {-0.03/22 109} 40. c5 {0.00/42 21} a4 {-0.03/22 0 (Le3)} 41. Rb1 {0.09/34 13} Be3 {-0.03/21 6} 42. Bb5 {0.09/38 11} Rd8 {-0.02/20 20 (Dxd4)} 43. Qc4 {0.00/42 29 (Dd3)} Qd2 {-0.02/19 49} 44. Qd3 { 0.00/42 10} Qxd3 {-0.01/20 11} 45. Bxd3 {0.00/44 31} Bxd4 {-0.02/18 23} 46. Ba6 {0.00/45 10 (Lc4)} a3 {-0.06/17 64} 47. c6 {0.00/44 11} a2 {-0.03/18 56} 48. Rf1 {0.00/46 10} Ne8 {-0.03/18 7} 49. Bxd4 {0.00/47 12} Rxd4 {-0.02/17 4} 50. Ra1 {0.00/48 11} Ra4 {-0.01/16 22} 51. Be2 {0.00/49 11} Nc7 {-0.01/16 13 (Kh6)} 52. h4 {0.00/45 10 (Ld1)} Kh6 {-0.08/12 83} 53. Kg2 {0.00/43 11 (Lf3)} Nd5 { -0.10/14 19 (Kh7)} 54. Kh2 {0.00/44 17 (Kf2)} Kh7 {-0.13/13 18} 55. Kh3 { 0.00/48 12} Ra3 {-0.15/14 14 (Kh6)} 56. c7 {0.00/47 12} Rc3 {-0.16/13 11} 57. Ba6 {0.00/49 9 (Txa2)} Nxf4+ {-0.09/14 48} 58. Kh2 {0.00/1 0} Rc2+ {-0.11/20 0 (Txc7)} 59. Kh1 {0.00/49 20 (Kg1)} Rxc7 {-0.14/17 13} 60. gxf4 {0.00/50 7} Rc2 {-0.12/16 6} 61. Bd3 {0.00/54 29} Rb2 {-0.11/14 10} 62. Kg1 {0.00/55 13} Kh8 { -0.09/14 32 (Tb3)} 63. Kf1 {0.00/48 19 (Kh1)} Rh2 {-0.08/13 18} 64. Kg1 { 0.00/49 40 (Ke1)} Rb2 {-0.09/13 9} 65. Kf1 {0.00/52 7} Kh7 {-0.06/12 9} 66. Ke1 {0.00/51 50 (Kg1)} Kh6 {-0.09/12 15} 67. Kf1 {0.00/52 37} Rh2 {-0.06/12 13} 68. Kg1 {0.00/49 4} Rb2 {-0.05/10 9} 69. Kf1 {0.00/51 6} Rh2 {-0.04/9 13} 70. Ke1 { 0.00/52 12 (Kg1)} Rh1+ {-0.09/10 16} 71. Bf1 {0.00/47 4} Rxh4 {-0.09/11 9 (Th2) } 72. Rxa2 {0.09/35 6} Rxf4 {-0.09/9 4} 73. Ra6 {0.09/42 8 (Tf2)} Kh7 {-0.10/9 16} 74. Be2 {0.09/46 7} g5 {-0.09/10 8} 75. Bh5 {0.09/46 7} g4 {-0.08/11 10} 76. Bg6+ {0.09/47 9} Kh6 {-0.05/10 5} 77. Bxf5+ {0.09/49 14} Kg5 {-0.04/9 25 (Kh5)} 78. Be6 {0.09/43 7 (Lc8)} g3 {-0.05/8 12} 79. Bd5 {0.09/42 7} Rf5 { -0.03/7 12 (Tf2)} 80. Bg2 {0.09/43 8} Rf2 {-0.02/7 10 (g6)} 81. Ra5+ {0.09/43 9 (La8)} Kh4 {-0.03/8 11 (Tf5)} 82. Ra4+ {0.09/46 15} Kg5 {-0.01/8 9} 83. Bf1 { 0.09/45 6 (La8)} Rh2 {-0.05/7 10 (Tf4)} 84. Be2 {0.09/45 9 (Ta7)} Rh1+ { -0.09/8 12 (Th4)} 85. Kd2 {0.48/42 6} Rh4 {-0.09/8 8} 86. Ra7 {0.48/43 8 (Ta1)} g6 {-0.07/8 11} 87. Ke3 {0.58/44 8 (Lf3)} g2 {-0.05/8 10 (Tf4)} 88. Ra5+ { 0.90/42 7 (Kf2)} Kh6 {-0.04/9 11 (Kf6)} 89. Kf2 {0.91/44 6} Re4 {-0.02/8 11 (Tb4)} 90. Bf3 {0.91/47 7} Rb4 {-0.02/7 10 (Td4)} 91. Kxg2 {0.91/47 8} Kg7 { 0.00/7 10 (Tb2+)} 92. Kg3 {0.91/43 9 (Ta2)} Kf6 {0.00/6 10} 93. Bd1 {0.91/42 7 (Ta2)} Rd4 {0.00/7 10 (Tb2)} 94. Bc2 {0.96/38 6 (Ta1)} Ke7 {0.00/7 10 (Td6)} 95. Bxg6 {1.08/39 7 (Ta2)} Rd8 {0.00/6 10 (Ke6)} 96. Be4 {1.08/43 9 (Ta7+)} Rd1 {0.00/6 10 (Tf8)} 97. Kf3 {1.09/48 14 (Kf4)} Rd8 {0.00/6 10 (Ke6)} 98. Bd5 { 1.09/46 6 (Kf4)} Kf6 {0.00/6 10 (Tf8+)} 99. Kf4 {1.10/43 10} Rd6 {0.01/7 7} 100. Rc5 {1.10/46 14 (Tb5)} Rb6 {0.01/7 11} 101. Bc4 {1.10/47 14 (Tc4)} Rb4 { 0.01/7 11 (Td6)} 102. Rc6+ {1.11/40 7} Ke7 {0.05/8 5} 103. Ke5 {1.11/43 64} Kd7 {0.08/8 13} 104. Rc5 {1.11/40 35 (Ld5)} Rb6 {0.05/8 8} 105. Bb5+ {1.11/44 19 (Ld5)} Ke7 {0.04/8 13} 106. Rc7+ {1.11/42 11} Kd8 {0.03/8 5} 107. Rd7+ { 1.11/41 10} Kc8 {0.04/8 7} 108. Rd5 {1.11/31 10 (La4)} Kc7 {0.02/8 15 (Kb7)} 109. Rd7+ {1.11/40 6 (Tc5+)} Kc8 {0.03/8 10 (Kb8)} 110. Rd5 {1.11/37 6 (Lc6)} Kc7 {0.02/7 13 (Kb7)} 111. Rc5+ {1.11/48 6} Kb7 {0.03/8 9 (Kd8)} 112. Bc4 { 1.11/35 19 (Lc6+)} Rh6 {0.03/7 9} 113. Bd5+ {1.11/41 5 (Le6)} Kb6 {0.04/7 9} 114. Rc8 {1.11/43 4} Rg6 {0.04/7 12} 115. Ra8 {1.11/40 21 (Kd4)} Rh6 {0.03/7 12 } 116. Rb8+ {1.11/44 11} Kc5 {0.02/7 6} 117. Rc8+ {1.11/43 11} Kb6 {0.05/8 14} 118. Rb8+ {1.11/36 4 (Kd4)} Kc5 {0.01/7 6} 119. Rc8+ {1.11/43 16} Kb6 {0.04/7 13} 120. Be4 {1.12/45 4 (Kd4)} Rh4 {0.02/7 12 (Ka5)} 121. Kd4 {1.12/41 5} Rh6 { 0.04/7 10 (Tf4)} 122. Rb8+ {1.12/44 5} Kc7 {0.02/7 5} 123. Rb7+ {1.12/42 23} Kc8 {0.06/8 13} 124. Rf7 {1.12/40 13 (Kc5)} Kd8 {0.04/7 9 (Th4)} 125. Kd5 { 1.12/40 9 (Ke5)} Ke8 {0.03/7 10 (Th4)} 126. Ra7 {1.12/36 9 (Tb7)} Rb6 {0.04/8 13 (Kd8)} 127. Bf5 {1.12/37 11 (Ke5)} Kf8 {0.07/8 10 (Tb5+)} 128. Be6 {1.12/34 10 (Ke5)} Ke8 {0.06/8 6} 129. Bf7+ {1.11/30 11 (Ke5)} Kd8 {0.06/8 14} 130. Kc5 {1.11/30 10} Rf6 {0.07/8 8} 131. Kd5 {1.11/29 10 (La2)} Rb6 {0.05/8 6} 132. Be6 {1.10/26 10 (Kc5)} Ke8 {0.04/8 9} 133. Bg4 {1.09/25 10 (Ke5)} Kd8 {0.04/7 17 (Kf8)} 134. Rd7+ {1.02/22 10 (Ld7)} Ke8 {0.02/7 4} 135. Rh7 {1.02/21 10 (Le6)} Kd8 {0.04/7 16} 136. Be6 {0.77/18 10 (Ld7)} Ke8 {0.04/8 10 (Tb5+)} 137. Ke5 { 1.02/30 10} Kd8 {0.05/8 6} 138. Rd7+ {0.09/34 10 (Ld7)} Kc8 {0.03/8 13} 139. Ra7+ {0.09/33 3 (Kd5)} Kb8 {0.02/7 8 (Kd8)} 140. Ra5 {0.09/39 17 (Ta4)} Kc7 { 0.01/7 11} 141. Ba2 {0.00/26 5 (Tc5+)} Rb2 {0.00/7 12 (Kb8)} 142. Bc4 {0.00/41 15 (Lg8)} Rh2 {0.00/6 10 (Tc2)} 143. Rc5+ {0.00/52 4 (Ta8)} Kb6 {0.00/4 9} 144. Rb5+ {0.00/65 5 (Tc8)} Kc6 {0.00/2 10 (Kc7)} 145. Bf1 {0.00/127 0 Draw agreed.} 1/2-1/2

Accuracy and technical skills

Even though it is not unusual for Fat Fritz to opt for a risky line, it still manages to hold its ground with a high degree of accuracy. One problem for Leela is that sometimes, without a good hardware, it misses some tactical paths, which can cloud its evaluation. While this is a more general problem for NNs not running on good hardware, it seems that FF is on its way to overcoming this hurdle. In the following game, FF manages its king quite well, and doesn’t get into any danger despite choosing a sub-optimal line.

[Event "Rapid match 20m+10s"] [Site ""] [Date "2019.10.24"] [Round "23"] [White "Fat Fritz"] [Black "Stockfish 10 64 POPCNT"] [Result "1/2-1/2"] [ECO "B09"] [Annotator "Elshan"] [SetUp "1"] [FEN "N4rk1/pp3pbp/4b1p1/8/4P3/2qB1Q1P/P1P1K1P1/1R5R b - - 0 19"] [PlyCount "48"] [EventDate "2019.??.??"] [TimeControl "1200+10"] {[#]} 19... Qc6 {0.00/39 40 [#] From this point onward, Fat Fritz demonstrates great and accurate defensive skills.} 20. Nb6 {0.22/26 65} axb6 {0.09/40 31} 21. Qe3 {0.22/31 0} Qc3 {0.00/39 14} 22. Qxb6 {0.19/32 37} Bc4 {0.00/42 21} 23. Bxc4 {0.15/32 29} Qxc4+ {0.00/45 141} 24. Kf3 {0.14/31 0} f5 {0.00/39 19 (Dc3+) } 25. e5 {0.16/20 174} Qe4+ {0.00/42 44} 26. Kf2 {0.15/22 0} Qf4+ {0.00/44 29} 27. Kg1 {0.12/23 62} Bxe5 {0.00/41 18} 28. Rd1 {0.12/22 0} Re8 {0.00/40 37} 29. Qf2 {0.12/22 0} Qa4 {0.00/40 26 (De4)} 30. h4 {0.12/16 96 (Df3)} Bb8 {0.00/42 21} 31. Re1 {0.10/19 116} Rd8 {0.00/44 38 (Tc8)} 32. Qf3 {0.09/14 50} Ba7+ { 0.00/42 14 (Dd4+)} 33. Kf1 {0.07/11 18} Rd2 {0.00/47 53 (Dc4+)} 34. Re2 { 0.09/17 54 (Db3+)} Rd1+ {0.00/45 29 (Txe2)} 35. Re1 {0.23/17 0} Qc4+ {0.00/45 24 (Db5+)} 36. Qe2 {0.05/9 33} Qf4+ {0.00/50 20} 37. Qf3 {0.03/7 23} Rxe1+ { 0.00/46 19 (Dc4+)} 38. Kxe1 {0.13/11 0} Qc1+ {0.00/51 21} 39. Qd1 {0.03/9 54 (Ke2)} Qe3+ {0.00/50 20} 40. Qe2 {0.01/7 31} Qc1+ {0.00/51 17} 41. Qd1 { 0.01/5 0} Qe3+ {0.00/52 49} 42. Qe2 {0.01/3 51} Qc1+ {0.00/58 85} 43. Qd1 { 0.00/2 0 Remis angenommen} 1/2-1/2

A Karpovian masterpiece

There are many good games in this match, and the Stockfish 10 wins are no less impressive, yet we are talking about FF, so the following positional masterpiece cannot go unnoticed. After obtaining a good positional advantage out of the opening, FF took his time until he realized his queenside breakthrough suffices, and he followed his play with a fantastic pseudo sacrifice. I will let the moves speak for themselves here:

[Event "Rapid match 20m+10s"] [Site ""] [Date "2019.10.25"] [Round "45"] [White "Fat Fritz"] [Black "Stockfish 10 64 POPCNT"] [Result "1-0"] [ECO "B90"] [Annotator "Elshan"] [PlyCount "135"] [EventDate "2019.??.??"] [TimeControl "1200+10"] 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 {Last Book move} 6. f3 { 0.43/14 19} e5 {0.00/31 40} 7. Nb3 {0.40/16 19} Be6 {0.16/34 81 (Le7)} 8. Be3 { 0.41/15 26} Be7 {0.30/33 50 (h5)} 9. Qd2 {0.43/20 30} O-O {0.15/33 48} 10. O-O-O {0.46/24 25} Nbd7 {0.17/35 24} 11. g4 {0.47/23 18} b5 {0.05/32 8} 12. g5 {0.46/22 23} Nh5 {0.00/35 19} 13. Kb1 {0.47/21 26} Nb6 {0.00/36 41} 14. Na5 { 0.48/21 19 (Sd5)} Rc8 {0.00/37 36 (Dc7)} 15. a3 {0.51/21 58 (Sd5)} g6 {0.00/35 21 (Dc7)} 16. h4 {0.54/18 64} Qc7 {0.00/37 10} 17. Rh2 {0.51/21 32} Rfe8 { 0.00/39 18} 18. Nd5 {0.60/20 67} Nxd5 {0.00/41 18} 19. exd5 {0.58/27 0} Bd7 { 0.00/43 19} 20. Qb4 {0.44/22 104 (Lh3)} Bf5 {0.00/38 41 (Sg3)} 21. Nc6 { 0.79/15 36} Bf8 {0.00/39 28} 22. Bd3 {0.75/15 27 (Lh3)} Bxd3 {0.00/40 22} 23. Rxd3 {0.73/16 11} f5 {0.00/40 17 (Dd7)} 24. Rb3 {0.71/16 50 (Td1)} Ng7 { 0.00/39 51 (f4)} 25. Re2 {0.77/16 76 (Th1)} f4 {0.00/38 30 (Df7)} 26. Bf2 { 0.78/14 18} Qf7 {0.00/36 13 (Sf5)} 27. Qe4 {0.83/14 29 (Td2)} Nf5 {0.00/38 53} 28. Rd2 {0.85/16 22} Bg7 {0.00/35 52 (h6)} 29. Rd1 {0.94/14 40 (c4)} Nd4 { 0.00/38 16} 30. Rc3 {0.92/13 47 (Tbd3)} Rc7 {0.11/39 187 (Sf5)} 31. Rcd3 { 0.89/13 43 (a4)} Nf5 {0.00/40 19 (Tcc8)} 32. Rb3 {0.84/13 57} Rb7 {0.00/43 128 (Se7)} 33. Rb4 {0.99/10 28 (Sa5)} Rf8 {0.00/37 20} 34. Rb3 {0.96/11 23} Qd7 { 0.00/35 23 (Te8)} 35. Rc1 {0.94/12 57 (Tc3)} Re8 {0.00/36 22 (Sg3)} 36. Rb4 { 0.97/10 37 (Tg1)} Kh8 {0.00/36 41 (Tf8)} 37. Rg1 {1.07/10 25} Rc8 {0.00/36 23 (Df7)} 38. Na5 {0.80/16 44 (Th1)} Rbb8 {0.00/40 12} 39. Nc6 {0.81/22 9} Rb7 { 0.00/40 22} 40. Rc1 {0.75/22 46 (Th1)} Rf8 {0.00/38 47 (Se7)} 41. Rb3 {1.02/12 24 (Th1)} Rc7 {0.00/38 21 (Df7)} 42. Ka2 {1.04/11 34 (Dd3)} Rb7 {0.00/35 19} 43. Rg1 {1.01/11 32 (Kb1)} Rc8 {0.00/38 32 (Df7)} 44. Rc1 {1.01/12 26 (Th1)} Qf7 {0.02/37 104 [#] (Tf8)} 45. c4 {1.24/17 29} Ng3 {0.54/37 100 (bxc4)} 46. Qd3 {1.24/18 28} bxc4 {0.59/31 13} 47. Qxc4 {1.19/18 13} Rxb3 {0.51/35 21} 48. Qxb3 {1.19/14 14} Re8 {0.45/34 8 (Dd7)} 49. Bb6 {1.41/19 39} Qd7 {0.52/34 15} 50. Nd8 $3 {1.62/21 19 It is not only for the depth but the briliant idea behind this move: Black must take and then:} Rxd8 {1.80/33 48} 51. Bxd8 { 1.73/22 14} Qxd8 {3.61/32 15} 52. Qb7 {1.78/21 9} Qg8 {3.99/35 20} 53. a4 $1 { 1.86/22 21 Black's two minor pieces are rather clumsy. Black loses one way or another.} Nf5 {4.13/34 15 (Lf8)} 54. Qxa6 {2.73/14 43} Qxd5+ {4.22/33 4} 55. Qc4 {3.02/16 25} Qg8 {4.47/37 13} 56. Qxg8+ {3.19/16 17 (a5)} Kxg8 {0.45/1 0} 57. a5 {3.29/15 8} e4 {4.49/32 9} 58. a6 {3.33/14 19} Bd4 {4.34/34 6} 59. Rc4 { 3.41/13 8 Threatening Rxd4 followed by a7-a8} Bg1 {4.85/35 13} 60. Rxe4 { 3.46/12 26} Kf7 {5.07/37 22 (d5)} 61. Rxf4 {4.33/11 32} d5 {5.38/36 12} 62. Rb4 {4.62/11 17} Ke6 {5.78/37 10 (Sd6)} 63. Rb7 {4.78/11 21} Nxh4 {6.29/37 10} 64. f4 {4.77/12 10 (b4)} Ng2 {5.04/25 3} 65. Rxh7 {4.77/12 35} Nxf4 {7.18/30 18} 66. a7 {4.99/12 1 (b4)} Bxa7 {7.00/26 3} 67. Rxa7 {4.69/10 8} d4 {9.25/29 17 (Sh3)} 68. Ra5 {5.61/9 26} 1-0

And finally, game 49 is another example of why NNs are so strong in positional chess.

[Event "Rapid match 20m+10s"] [Site ""] [Date "2019.10.25"] [Round "49"] [White "Fat Fritz"] [Black "Stockfish 10 64 POPCNT"] [Result "1-0"] [ECO "C02"] [Annotator "Elshan"] [PlyCount "145"] [EventDate "2019.??.??"] [TimeControl "1200+10"] 1. e4 e6 2. d4 d5 3. e5 c5 4. c3 Nc6 5. Nf3 Qb6 6. a3 c4 {Last book move.} 7. Nbd2 {0.35/14 20} Na5 {-0.25/33 77} 8. Rb1 {0.35/14 22} Bd7 {-0.17/31 15} 9. Be2 {0.37/15 31} Ne7 {-0.32/33 30 (0-0-0)} 10. h4 {0.39/14 30 (0-0)} O-O-O { -0.27/33 66} 11. h5 {0.37/16 21 (Sf1)} Kb8 {-0.25/33 29 (f6)} 12. Nf1 {0.47/13 41} h6 {-0.19/31 23} 13. Bf4 {0.49/12 31} Nb3 {-0.11/32 57 (a6)} 14. Ne3 { 0.63/12 67 (S3d2)} Ba4 {-0.04/33 23 (Ka8)} 15. Nd2 {0.70/12 32} Nc6 {0.00/31 30 (Sxd2)} 16. Nxb3 {0.70/13 35 (Lg3)} Na5 {0.00/34 72} 17. Kf1 {0.65/13 66 (Lg3)} Bxb3 {0.00/40 26 (a6)} 18. Qd2 {0.68/14 20} Ba4 {0.00/39 11} 19. Bd1 { 0.67/13 20 (De1)} Bxd1 {0.00/35 17} 20. Rxd1 {0.66/12 25} a6 {0.00/37 16 (Le7)} 21. Rh3 {0.64/10 92 (Lg3)} Be7 {0.00/37 36} 22. Kg1 {0.62/11 41 (Lg3)} Rdg8 { 0.00/35 13} 23. Bh2 {0.59/11 36 (De2)} Qd8 {0.00/35 34 (Ka7)} 24. Qe2 {0.56/10 43 (Lg3)} Ka7 {0.00/37 39} 25. f4 {0.56/11 19 (Df3)} g6 {0.00/29 16} 26. g4 { 0.62/12 24 (Dg4)} Nb3 {0.00/33 56 (Sc6)} 27. Kh1 {0.72/11 42} Qe8 {0.00/38 41 (Dd7)} 28. Qf3 {0.73/14 31} Bd8 {0.00/37 35 (Th7)} 29. hxg6 {0.77/18 34} Rxg6 { 0.09/32 31 (fxg6)} 30. f5 {1.86/13 33 (Lg3)} Rg7 {0.00/38 34 (Tgg8)} 31. f6 { 1.89/13 24 (Lf4)} Rg6 {0.97/34 66} 32. Bf4 {1.89/11 22} Bc7 {1.00/35 28} 33. Ng2 {1.95/11 53 (Kg2)} Qg8 {1.34/26 82} 34. Rh4 {1.96/11 20} Qd8 {1.82/30 158 (Dh7)} 35. Be3 {2.27/11 49 (Kh2)} Na5 {2.46/30 84 (Dg8)} 36. Rd2 {2.40/11 39 (Sf4)} Nb3 {2.44/32 17 (Sc6)} 37. Rf2 {2.57/11 39 (Td1)} Rgg8 {3.38/30 83 (Dg8) } 38. Bxh6 {2.89/10 41 (Sf4)} Qd7 {3.65/26 36 (Lb6)} 39. Be3 {3.16/9 51 (g5)} Rxh4+ {4.29/30 54 (Sa5)} 40. Nxh4 {3.37/10 28} Rh8 {4.55/29 14} 41. Rh2 { 3.57/10 27} Na5 {5.06/34 56 (Da4)} 42. g5 {3.92/9 43 (Sg2)} Nc6 {5.17/32 22} 43. Ng2 {4.05/9 36} Rg8 {5.35/32 15 (De8)} 44. Rh7 {4.21/8 49} Nd8 {5.45/31 15 (Lb6)} 45. Qd1 {4.33/8 32 (Tg7)} Qb5 {4.48/27 19 (De8)} 46. Qc2 {4.56/8 24 (De2)} Qb6 {5.14/32 58 (De8)} 47. Kg1 {5.08/8 45 (De2)} Kb8 {5.43/31 29 (Lb8)} 48. Kf1 {5.45/8 35 (De2)} Ka7 {5.47/29 15} 49. Kf2 {5.48/8 25 (Kg1)} Qc6 { 6.00/29 16 (Sc6)} 50. Nh4 {5.36/7 26} Rf8 {6.40/31 10 (De8)} 51. Nf3 {6.20/7 21 (g6)} Rg8 {6.60/29 10 (De8)} 52. Kg3 {5.99/7 26 (Sh4)} Ba5 {5.51/26 10 (De8) } 53. Bf4 {6.00/7 23 (Sh4)} Qb5 {5.56/29 10 (De8)} 54. Rh6 {5.74/7 21 (Sh4)} Rf8 {5.74/29 10 (De8)} 55. Rh7 {5.85/7 19} Rg8 {5.51/28 5} 56. Bd2 {5.44/7 18 (Sh4)} Bc7 {5.61/28 10 (De8)} 57. a4 {5.43/7 19 (Sh4)} Qc6 {5.20/24 7 (De8)} 58. Be3 {5.43/7 17 (Sh4)} Kb8 {5.66/29 18 (De8)} 59. Kg4 {5.44/7 16 (Sh4)} b5 { 5.38/24 7 (De8)} 60. axb5 {6.18/8 9} Qxb5 {6.24/28 12 (axb5)} 61. Rh2 {6.69/7 18 (Sh4)} Qe8 {6.27/28 10 (a5)} 62. Kg3 {6.81/7 15 (Dh7)} a5 {5.58/24 4 (Th8)} 63. Rh7 {5.96/7 15 (Dh7)} a4 {5.34/25 6} 64. Rh1 {6.03/7 9 (Th6)} Ba5 {5.60/28 19 (Db5)} 65. Ra1 {7.48/7 11 (Th6)} Bb6 {5.85/24 11 (Th8)} 66. Qxa4 {11.19/7 11 (Txa4)} Qxa4 {5.22/28 2} 67. Rxa4 {11.46/8 8} Kc7 {6.13/34 18 (Sc6)} 68. Ra1 {16.83/7 22} Rh8 {6.59/31 7 (Sc6)} 69. Rg1 {15.38/7 13 (g6)} Kc6 {6.30/31 8 (Kd7)} 70. Rb1 {14.77/7 11 (Tf1)} Kd7 {6.68/31 15 (Lxd4)} 71. Bf4 {14.01/7 11 (Tf1)} Ba5 {6.65/31 9 (Lxd4)} 72. Ra1 {13.33/7 11 (g6)} Bc7 {6.69/34 5 (Lxc3)} 73. Kg4 {13.55/7 11 (g6)} 1-0

Finally, here is the complete set of games:

Replay all games Fat Fritz vs Stockfish 8

 

Replay all games Fat Fritz vs Stockfish 10

 

Answering reader questions

There are obviously further experiments to run, and all top engines are under continuous development. Thanks for all your suggestions and feedback in the comments to part one.

To clarify what the "the Silver Openings Suite" is, as Albert Silver explained:

It is comprised of 50 positions, which are designed to cover the basic range of openings, and opening structures, in proportions roughly comparable to their popularity in Mega.

The match uses these 50 positions, all of which are played twice with colors reversed the second time. In other words, for every position Stockfish had white in one and black in the other, and same goes for Fat Fritz.


Check back for more exciting Fat Fritz news in the coming days!



Elshan Moradiabadi is a GM born and raised in Tehran, Iran. He moved to the US in 2012. Ever since, he has been active in US college chess scenes and in US chess. is a veteran instructor and teaches chess to every level, with students ranging from beginners to IM. He can be contacted for projects or teaching.