30th Leiden Computer Chess: Rybka on 260 cores wins

30th Open Dutch Computer Chess Championship

In the nearly esoteric world of computer chess, a few events consistently have a draw of the very top competitors who bring in everything they can to come out on top. The World Computer Chess Championship is an obvious candidate, but right behind it today, is the Open Dutch Computer Chess Championship, now celebrating its 30th edition no less.

The traditional Open Dutch Computer Chess championship celebrated its 30th birthday

Its attraction to the participants is not simply a trophy to add to their shelf, and financially, there is certainly no direct gain to be had. No, the interest is in the opportunity for the teams to test their toughest imaginable setups, meet other programmers with whom they can exchange ideas and swap stories, and all done in an environment of fairplay and transparency. Not to mention the comparably accessible venue (2010 WCCC was held in Japan, which was a huge expense for the teams).

The playing hall is prepared for the compeititon

The event also had no less than three supercomputers playing. There was Jonny, a German program running on a massive cluster of 800 Intel i7 cores. The programmer, Johannes Zwangzer, was running it remotely on his university’s hardware; the University of Beyreuth has 2000. Next is Deep Sjeng by Gian-Carlo Pascutto, residing in Belgium, whose engine ran on a cluster of 32 x 8 AMD Opterons (256 total) running at 2.4 GHz, and then there was the reigning champion, Rybka, running on a cluster owned privately by Lukas Cimiotti, containing 248 Intel i7 cores at 2.93 GHz, later increased to 260.

Participants

When just goggling at the sheer size, a few things are worth noting to put things in perspective. Several days and nights of non-stop computing by Rybka on a normal quad-core, would equate to less than an hour on Lukas’s cluster. On the other hand, despite the huge number of processors at its disposal (800), Jonny is a serious underdog to Rybka, despite running on a three times the number of cores. The reason is that one needs to take into account just how much strength each doubling in speed actually brings. In theory, presuming they are equally efficient at running on such hardware, double the speed means a 50-70 Elo gain, however in terms of pure software, Jonny is nowhere near 100 Elo of Rybka.

Hans van der Zijden operating Rybka facing Hiarcs operated by Harvey Williamson

The competition went smoothly, with the organizers providing cable connections for the programmers, half of whom were playing remotely, to avoid even irregularities that WiFi might be subject to. Even so, delays sometimes did take place, but all done so that no one was penalized by this. They also provided daily reports with pictures at their website, for the aficionados.

Needless to say, such mind-boggling hardware and software combinations led to some remarkable games, and situations. The game of the tournament was Rybka’s powerful win over supercluster Jonny in the 5th round.

Jonny (800 cores) - Rybka 4.x (260 cores) [A87]
30 ODCCC Leiden (4), 27.11.2010

1.d4 f5 2.g3 Nf6 3.Bg2 g6 4.Nf3 Bg7 5.c4 0-0 6.0-0 d6 7.Nc3 e6 8.Qc2 Nc6 9.Rd1 Qe7 10.a3 a5 11.Be3 Nd8 12.Ra2. 800 processors, and the move is Ra2? 12...b6 13.Ng5 Bb7 14.Bxb7 Nxb7 15.h3 a4!

This sacrifice is typical of the top engines, and frees the a5 square for either the knight, or rook depending on Black's reply. 16.Nxa4 Nh5 17.Kh2 e5 18.dxe5 Bxe5 19.Nf3 f4 20.gxf4 Bxf4+ 21.Bxf4 Nxf4 22.Nc3 Qe6 23.Ng1

23...Ra5! When attacking, make sure everyone is invited to the party, and Rybka doesn't need to be told twice. 24.Qe4 Re5. Avoiding the exchange and decoying the queen away from its king. 25.Qxb7. Trying to stay around the king to defend with 25.Qf3? Nxe2 26.Qg2 Ref5 27.Rf1

fails spectacularly to 27...Rxf2!! 28.Rxf2 Qe5+ 29.Kh1 Ng3+ 30.Kh2 Ne4+ 31.Kh1 Nxf2+ 25...Rh5 26.Qe4

26...Rxh3+! 27.Nxh3 Qxh3+ 28.Kg1 Rf5! Threatening Rg5+ 29.Rd5 Nxd5 30.Qe8+ Kg7 31.Qd7+ Kh6 32.Qxf5. The only way to prevent an immediate mate, but of course White is lost. 32...Qxf5 33.cxd5 Qg5+ 34.Kh2 Qd2 0-1 [Click to replay]

On the other hand, in one of those situations that computers simply cannot see, Jonny was actually forced into a draw by Scaramanga, which ran on a single core, when it found itself in a remarkable study-like position where its queen against bishop was insufficient.

Johannes Zwangzer operating his program Jonny against Scaramanga handled by
Hans Secelle.

Scaramanga (1 core) - Jonny (800 cores) [D48]
30 ODCCC Leiden (5), 27.11.2010

1.d4 d5 2.c4 e6 3.Nc3 c6 4.e3 Nd7 5.Bd3 Ngf6 6.Nf3 dxc4 7.Bxc4 b5 8.Bd3 a6 9.a4 Bb7 10.0-0 b4 11.Ne4 c5 12.Ned2 Be7 13.Qe2 Qc7 14.Nc4 0-0 15.Rd1 Rfd8 16.Nfe5 a5 17.Bd2 Bd5 18.Rac1 Rac8 19.Be1 cxd4 20.exd4 Nxe5 21.dxe5 Nd7 22.Ne3 Qxc1 23.Rxc1 Rxc1 24.Nxd5 exd5 25.e6 Nc5 26.Bxh7+ Kf8 27.g3 Nxe6 28.Kg2 Rc5 29.f4 Rc1 30.Bf2 d4 31.Bc2 Nc5 32.Qh5 Ke8 33.Bd1 d3 34.Be3 d2 35.Qh8+ Bf8 36.Qh5 g6 37.Qe2 Be7 38.g4 Kf8 39.f5 g5 40.h4 Ne4 41.Kf3 Bc5 42.Bxg5 Rxd1 43.Qxd1 Nf2 44.Qxd2 Rxd2 45.Bxd2 b3 46.Bc3 Nd1 47.Be5 Ne3 48.Bc3 Nc4 49.g5 Nb6 50.h5 Nxa4 51.Be5 Kg8 52.Ke2 Nb6 53.g6 Bf8 54.Kd3 a4 55.f6 Nd7 56.Bc3 Bd6 57.Kc4 Nf8 58.Kd5 a3 59.Kxd6 a2 60.Ke7 fxg6 61.f7+ Kh7 62.Kxf8 a1Q

63.h6! This move results in a study-like position in which Black cannot win despite the huge material advantage. The king is cut off and the queen has nothing better to do than a perpetual. 63...Qa8+ 64.Ke7 Qb7+ 65.Ke6 Qa6+ 66.Ke7 Qe2+ 67.Kd7 Qd3+ 68.Ke8 Qb5+ 69.Ke7 Qc5+ 70.Ke8 Qe3+ 71.Kd7 Qf4 72.Ke7 Qe4+ 73.Kd6 Qd3+ 74.Ke7 Qe3+ 75.Kd7 Qf2 76.Ke8 Qe2+ 77.Kd7 Qg4+ 78.Ke7 Qg5+ 79.Ke8 Qb5+ 80.Ke7 Qc5+ 81.Ke8 Qc6+ 82.Ke7 Qc7+ 83.Ke8 Qb8+ 84.Ke7 Qa7+ 85.Ke8 Qa4+ 86.Ke7 Qh4+ 87.Ke8 Qe4+ 88.Kd7 Qf3 89.Ke7 1/2-1/2 [Click to replay]

On paper, Rybka was the clear favorite with huge hardware, and the strongest program, and sure enough this favoritism translated to a crushing 8.5/9 result, 2.5 points ahead of the field, and only dropping a half-point to Spark, running on a modest quad-core. All elbowing for sole second place, but eventually sharing the honors were Spike, Deep Sjeng, and Hiarcs with 6.0/9.

The operators holding the trophies of the winning programs

Photos by Jan Krabbenbos, CSVN Tournament Director & Webmaster

Final standings

Links Official tournament site All games in PGN To read, replay and analyse the PGN games we adivse you to download the free PGN reader ChessBase Light. This program also gives you immediate access to the chess server Playchess.com.