The Philidor Position: turning point of Moscow

Philidor Position (R+B vs R)

By Thomas W. Ewers

During the official FIDE live broadcast, the commentators did not know how to win from this well known position. In fact, in another broadcast commentated by Jan Gustafsson, he admitted to not being an expert on this endgame and he and his co-commentator, Robin van Kampen, tried but failed to show the winning method. In Jan's defense, he at least knew the key square that you need to initially drive the defending rook (f3 in Caruana - Svidler, which is c3 in the original Philidor position).

I also viewed the "Today In Chess" (Chess Club and Scholastic Center of St Louis, CCSCSL) live video with grandmasters Yasser Seirawan, Maurice Ashley and Alejandro Ramirez, and they could not show the winning method without consulting an endgame tablebase and playing through the moves one by one. After this discussion there was a telephone conversation with Garry Kasparov who said in disbelief, "You just spent 15 minutes discussing the well-known Philidor position!"

In the FIDE World Cup 2015, the game Kramnik - Bruzon ended with Kramnik winning while starting from a drawn position. Peter Svidler(!!) was doing the live commentary for this game and during that game, Peter and his co-commentator seemed to struggle differentiating some positions (before the Philidor position was reached) as winning or drawn. Hearing even a world class player such as Svidler describing the general endgame as "extremely complex" prompted me to learn more about R+B vs R and see how difficult it really was.

Top 100 GM Lazaro Bruzon from Cuba lost his way in this endgame against Vladimir Kramnik in 2015
In the game Carlsen - Ding Liren, Tata Steel 2016, Ding properly held the position using the "second rank defense". During the CCSCSL broadcast, Yasser Seirawan displayed the defensive setup known as the "Cochrane position", although he called it the "Szen" position which is a different defensive setup.

Ding Liren was well-versed and held the endgame against Magnus Carlsen in a key matchup
in the final round of the Tata Steel 2016 event, allowing him to finish third. Since even elite grandmasters seem to have some confusion with knowing how to win from the standard Philidor position I would like to explain my understanding of the position so that others might be able to remember the winning technique when needed. I used Basic Chess Endings (BCE) by Fine (1973, Descriptive Notation) and the Syzygy Endgame TableBases as references. Dvoretsky's Endgame Manual has the Philidor, Szen, and Cochrane positions while BCE has additional R+B vs R endgames which are even more complex.

The Philidor Position

White to play and win
Let me state some general observations even though they may seem obvious:

1. There are 3 files to the left of the Kings, and 4 files to the right of the Kings.

2. The Bishop controls the corner square on the short side of the board.

3. If you remove the Black Rook, then the standard checkmate positions with the White Rook occur. There are five of these.

4. If you remove the Black Rook and move the Black King one square in either direction, the White Rook still checkmates along the back rank because the Bishop controls b7 and f7. There are 5 of these for each Black King position.

5. If you remove the Black Rook and move the Black King two squares in either direction, the White Rook checkmates at a8 or g8 accordingly.

6. If you remove the Rooks from the starting position, and then place the White Rook at f7, g7, or h7 with White to move, then the Black Rook must occupy a square on the e file to block the checkmate on the back rank. If the Black Rook was on the back rank from e8 to h8, then Ra7 wins quickly. The squares e1, e2, and e3 are available. A similar situation occurs on the short side with the White Rook at b7 and the Black Rook on the c file. 

7. Most of the action in this endgame occurs on the "short" side of the board.

Philidor's classic work on chess

There are several key positions before checkmate is delivered. In the main variation the White King never moves. The Final Key Position occurs after move 11...Kd8 in the main variation (mate in 4 or capture Black's Rook).

Final Key Position

White to move and win

12. Bc4 Kc8 13. Be6+ Kd8 14. Rb8+ Rc8 15. Rxc8 mate.

Note how the Bishop blocks the Black Rook's path to c8 and the White Rook protects the Bishop and threatens mate. The Bishop also controls the d3 square from a Rook check, which is why you want the Black Rook on c3 instead of c1.

While learning this endgame always keep in mind the Final Key Position.

At the end of the article is a PGN with the analysis in this article, but you are encouraged to try to follow it in your mind's eye

Reaching the Final Key Position

White to play and win

The general technique for getting to this Final Key Position is to play moves that take away Black's options. There are several positions where White gains a move. That is, you start with one position and later it appears as though White has moved a piece and it is now White's turn to move again. You may want to briefly play through the main variation at this time before continuing.

The first two moves are very natural and easy to find. For the most part the White Rook wants to occupy the 7th rank and manuver laterally along it.

 
1. Rf8+ Re8 2. Rf7 Re2

At first sight you might not believe it when I say that e2 is a better square for the defense than e1, and e1 is a better square than e3. Hopefully when you are done with this lesson you will understand why. For now just believe me. Svidler played the equivalent of Re1 which is suboptimal when trying to achieve the 50 move draw.

Since the Black Rook is on the best defensive square, you can force it to one of the other squares by playing a waiting move:

3. Rg7 Re1

3...Re3 would transpose into a shorter version of the main line after 4. Rb7, although the quickest way to mate after 3...Re3 is 4. Rd7 which is almost a mirror image of the main variation after 8. Rd7 (see offset "i" position).
 
4. Rb7

You might be tempted to play 4. Bf3?? similar to 5. Bb3 in the main line on the short side, but it only draws(!) after 4...Ke8. The reason it fails here is because the White Rook is not on f7.

Note 4. Ra7?! Rc1 5. Bb3 is only mate (or capture Rook) in 13 moves which is longer than the main variation. During the CCSCSL broadcast they tried a similar plan.

The action now shifts to the short side. There are two ways for Black to defend. 4...Kc8 leads to the "Skewer the Rook" variation which includes a Rook check in the Bishop controlled corner. 4...Kc8 5. Ra7 Rb1 6. Rh7 Kb8 7. Rh8+ Kh7 8. Ra8+ Kb6 9. Rb8+ and 10. Rxb1
 
4...Rc1 5. Bb3! 

After 5.Bb3!

Fabiano incorrectly played a move equivalent to this but with the Rooks still on the "long" side. Black has two ways to defend.

5...Rc3

If Black refuses to place his rook on c3 and instead plays 5...Kc8, you use the "Rectangle Rook" variation (Rook from g7 to b7 to b4 to g4). 6. Rb4 Kd8 (6...Rc3 7. Be6, etc.) 7. Rg4. Black has three possible responses: 

A) 7...Ke8 8. Ba4, etc.

B) 7...Kc8 8. Bd5 Kb8 9. Ra4 and 10. Ra8 to follow.

C) 7...Re1 8. Ba4 Kc8 9. Bc6 Rd1 10. Bd5 Kb8 11. Ra4 and Ra8 to follow.

5...Rc3 is the only reasonable move for the Rook, and you are getting closer to the Final Key Position. The next manuver is used to reach the Offset "i" position.

 
6. Be6 Rd3+ 7. Bd5 Rc3

If 7...Kc8, then 8. Ra7 and mate to follow.

The next maneuver is intended to win another tempo. You want to play the move Rb4 and have it be White's turn to move. Compare to the Final Key Position after 11...Kd8.

8. Rd7

Offset "i" Position:

Black to move

8...Kc8

If 8...Ke8, then 9. Rg7 and threat Rg8.

 
9. Rf7 Kb8 10. Rb7+ Kc8 11. Rb4 Kd8

if 11...Rd3 then 12. Ra4, and if 11...Rc2 then 12. Be6+.

Final Key Position

White to play and win

12. Bc4 Kc8 13. Be6+ Kd8 14. Rb8+ Rc8 15. Rxc8 mate.

In summary, you need to know: 

1. Phildor position; 

2. Skewer the Rook variation;

3. Rectangle Rook variation;

4. Offset 'i' position;

5. Final key position. 

Hopefully you have learned from this lesson!

Analysis for replay: