Wrong rook pawn

In chess endgames with a bishop, a pawn that is a rook pawn may be the wrong rook pawn. With a single bishop, the result of a position may depend on whether or not the bishop controls the square on the chessboard on which the pawn would promote. Since a side's rook pawns promote on opposite-colored squares, one of them may be the "wrong rook pawn" (Burgess 2000:494). This situation is also known as having the wrong-colored bishop or wrong bishop, i.e. the bishop is on the wrong colored squares in relation to the rook pawn (Rosen 2003:61). In many cases, the wrong rook pawn will only draw, when any other pawn would win. A fairly common defensive tactic is to get into one of these drawn endgames, often through a sacrifice.

In some endgames such as having a bishop and pawn versus a lone king (perhaps with pawns), the wrong rook pawn is the one whose promotion square is the opposite color as that on which the bishop resides, which makes the stronger side unable to win. This was known at least as early as 1623 because of an endgame study by Gioachino Greco (see below).

A less common situation is when the defense has a bishop versus a rook and rook pawn; the wrong rook pawn is the one that promotes on the square not controlled by the bishop because the defending king and bishop can form a blockade in the corner (on the pawn's promotion square) and draw the game. (This is also called the safe corner for the defending king.)


Bishop and pawn

Müller & Lamprecht
abcdefgh
8
a8 black king
e7 white bishop
a6 white pawn
b6 white king
8
77
66
55
44
33
22
11
abcdefgh
The wrong rook pawn, draw with either side to move (can just as well be described as wrong colour of the bishop)

In this type of endgame, the wrong rook pawn is the one whose queening square is the opposite color as that on which the bishop resides. Many such positions are drawn because of a fortress if the defending king can get to the corner in front of the pawn, see the diagram. With the bishop not able to control the a8 square, the black king cannot be forced away from the corner, so the pawn will not be able to promote (Müller & Lamprecht 2001:96–100). This is the basic type of position for most of these endgames (Mednis 1987:64).

Defending king in front of pawn

Mednis, 1987
abcdefgh
8
f8 white king
f7 white bishop
h6 black king
h5 white pawn
8
77
66
55
44
33
22
11
abcdefgh
White to move wins. Black to move draws.

In a king and pawn versus king endgame with a rook pawn, the defending king only has to get in front of the pawn to draw the game. In contrast, in the endgame with a bishop and the wrong rook pawn, getting the defending king in front of the pawn will not necessarily draw. In this position from Edmar Mednis, White wins if it is his move

1. Kg8! Kg5
2. Kg7

and the pawn promotes. Black to move draws by 1... Kh7! followed by 2... Kh8. The defending king must be in the corner or be next to it to be sure of a draw (Mednis 1987:64–65).

Examples from games

Goglidze versus Kasparian

Goglidze vs. Kasparian, 1929
abcdefgh
8
f7 white bishop
g7 black king
e6 white king
e5 white pawn
h5 white pawn
d1 black bishop
8
77
66
55
44
33
22
11
abcdefgh
Black to move draws with 1... Bg4+!

In this position from a 1929 game between Viktor Arsentievich Goglidze and Genrikh Kasparian, Black uses the tactic of offering the sacrifice of his bishop for the pawn on the e file to leave White with the wrong rook pawn:

1... Bg4+!

and the game was drawn twelve moves later. The bishop will remain on the c8 to h3 diagonal and sacrifice itself for the e-pawn if it advances to e6. (Note that 1... Bb3+ 2. Ke7 Bxf7 does not work because of 3. h6+!) (van Perlo 2006:356).

Fischer versus Taimanov

Fischer vs. Taimanov, 1971
abcdefgh
8
f6 white king
d5 black king
e5 black knight
g4 white bishop
h3 white pawn
8
77
66
55
44
33
22
11
abcdefgh
Black to move can draw.

In this game from the 1971 World Chess Championship Candidate's Match, the second game between Bobby Fischer and Mark Taimanov, Black could have drawn the game because of the wrong rook pawn. One way is:

81... Nd3!
82. h4 Nf4
83. Kf5 Kd6!
84. Kxf4 Ke7
½-½

In the actual game,[1] Black made an incorrect move (81... Ke4??) and lost because a knight has a hard time defending against rook pawns (Dvoretsky 2006:82–84), (Benko 2007:213). (Fischer went on to win the match 6-0 and advance to the next round, and subsequently became World Champion.)

Ķeņģis vs. Kasparov

Ķeņģis vs. Kasparov, 1973
abcdefgh
8
a6 black pawn
e5 white bishop
f5 black pawn
e4 black bishop
g4 black king
b3 white pawn
d3 black pawn
e3 white king
8
77
66
55
44
33
22
11
abcdefgh
Black to move, draw

Ten-year-old Garry Kasparov[2] thought that he was winning this game as Black against Edvīns Ķeņģis, being two pawns ahead.[3] Indeed, Black can win the white bishop (for two pawns), but then the game is a draw because of the wrong rook pawn. In the actual game, Black moved 48...Kh3 and the game was drawn after move 54. (No progress can be made with the bishops on opposite colors, see opposite-colored bishop endgame.) In an alternative line, Black can win the white bishop:

48...f4+
49.Bxf4 d2
50. Kxd2 Kxf4

but the position is drawn because the black rook pawn is on the wrong file for the bishop to help promote it (Kasparov 2011:23–24).

Karpov versus Kasparov

Karpov vs. Kasparov, 1985
abcdefgh
8
f7 black bishop
d6 black king
g6 black pawn
a5 black pawn
b5 white bishop
f5 black pawn
a4 white pawn
d4 white king
f4 white pawn
h4 white pawn
8
77
66
55
44
33
22
11
abcdefgh
Position after 82.Kd4. Black sacrifices two pawns for one to leave White with the wrong rook pawn.

Garry Kasparov used sacrifices to leave Anatoly Karpov with the wrong rook pawn to save the twentieth game of their 1985 World Championship, after a long endgame.[4] In this position, Black sacrificed two pawns for one (the ones on f5 and g6 for the one on a4):

82... Bb3!
83. Be8 Ke7
84. Bxg6 Bxa4
85. Bxf5 Kf6
½-½

A draw was agreed because the black bishop can stop the advance of the pawn on the f-file, sacrificing itself if necessary, leaving White with the wrong rook pawn (the one on the h file) (Mednis 1990:73–74), (Kasparov 2008:385). (Kasparov went on to win the match 13-11 and became World Champion for the first time.)

Korchnoi versus Karpov

Korchnoi vs. Karpov, 1978
abcdefgh
8
b5 black pawn
f5 white king
a4 black pawn
f4 white bishop
a3 white pawn
f3 black king
8
77
66
55
44
33
22
11
abcdefgh
Position after 99.Bf4

In this game[5] from the 1978 World Championship between Victor Korchnoi and Anatoly Karpov, White's pawn is the wrong rook pawn. White went on to capture the black b-pawn on move 107, but was unable to force the black king far enough away from the a8 square to get to a winning position. The game ended in an intentional stalemate on move 124 (see Stalemate#Korchnoi versus Karpov for the final position). Some commentators thought that Korchnoi might have missed a win in this endgame, but Karpov defended well and White never had a theoretically won position. (However, Korchnoi did miss a win earlier in the game.) Black's pawn on b5 is actually a liability. If the black king is forced into a position where he cannot move, black would have to move the pawn and White would win the game. As of 2008, this is the longest game of a world championship (Griffiths 1992:43–46), (Kasparov 2006:112–20). (Karpov retained his title by a score of six wins to five.)

An exception

from Griffiths
abcdefgh
8
a8 black king
b7 black pawn
d7 white king
a6 black pawn
b6 white bishop
a5 white pawn
8
77
66
55
44
33
22
11
abcdefgh
White to move wins, an exception because of the black pawns.

In this position White wins because he is able to force the exchange of pawns to get his pawn on the b-file.

1. Be3 Kb8
2. Bd4 Ka8
3. Kc8

and checkmate in two more moves. If Black did not have his rook pawn, he could draw by 3... b5 (Griffiths 1976:93).

Opposite-colored bishops

Fine & Benko, position 418
abcdefgh
8
a8 black king
f6 white pawn
a5 white pawn
b5 white king
d5 black bishop
e3 white bishop
8
77
66
55
44
33
22
11
abcdefgh
Draw because of the wrong rook pawn

Usually when each side has a bishop and they are on opposite-colored squares and one side has two widely-separated pawns, the stronger side wins. However, if one of the pawns is the wrong rook pawn and the defending king is blocking it, the position is usually a draw because the defending bishop can stop the other pawn. If the defending bishop is sacrificed for the other pawn, the resulting position is a draw like the ones above (Fine & Benko 2003:192).

de la Villa, position 9.3
abcdefgh
8
g8 black king
g6 white pawn
h6 white pawn
f5 white king
c4 white bishop
c3 black bishop
8
77
66
55
44
33
22
11
abcdefgh
Draw because of wrong rook pawn

With opposite-colored bishops, two connected pawns win if they safely reach the sixth rank, except when one is the wrong rook pawn, i.e. the defending bishop is on the long diagonal that includes the square on which the rook pawn would promote (de la Villa 2008:106).

Example from game

Walther vs. Fischer, 1959
abcdefgh
8
d7 black king
d6 black bishop
b5 white king
a4 white pawn
h4 black pawn
f3 white bishop
h3 white pawn
b2 white pawn
8
77
66
55
44
33
22
11
abcdefgh
Position after 54.a4?

in this game between FIDE Master Edgar Walther and Bobby Fischer,[6] White has just made a bad move (54. a4?; 54. b4! wins). Black's defensive plan is to sacrifice his bishop for the two queenside pawns, leaving White with the wrong rook pawn (the h-pawn) for his bishop. The game was drawn nine moves later (Fischer 2008:67), (Dvoretsky 2006:94).

Rook and rook pawn versus bishop

Berger (Fine & Benko, position 930)
abcdefgh
8
h8 black king
g7 white rook
f6 white king
h5 white pawn
b1 black bishop
8
77
66
55
44
33
22
11
abcdefgh
White to move, draw

The wrong rook pawn may come up in other situations, such as this position with a rook and rook pawn versus a bishop. This time the bishop is defending against the rook pawn. If the pawn had not yet reached the fifth rank, White would win. Play might continue:

1. Rb7 Bc2
2. Kg5 Bd3
3. Kh6 Kg8!
4. Rg7+ Kf8!! (4... Kh8?? loses)
½-½

White cannot win because his king cannot move to the h5 square. If the bishop were on the other colored squares, White would win (Fine & Benko 2003:468–72).

If the defending king is in the corner controlled by his bishop then the pawn can be sacrificed at the right moment to get to a winning rook versus bishop position. If the defending king is in the corner opposite his bishop's color, sacrificing the pawn does not work because the defender easily forms a fortress in the corner (Müller & Lamprecht 2001:271–72). This is also referred to as the defending king being in the "safe" corner, since with the king in the corner with the bishop next to it, he is safe from the rook.

Examples from games

Euwe vs. Hromádka, 1922
abcdefgh
8
h5 black pawn
g4 black king
a2 black rook
f2 white bishop
g1 white king
8
77
66
55
44
33
22
11
abcdefgh
Black to move should win, but errs and allows a draw.

In this position from a game between future World Champion Max Euwe and Karel Hromádka, Black should win but he errs by advancing his pawn too soon.[7] Play continued:

1... h4?? (Black wins easily after 1... Kh3!)
2. Bd4 Kh3? (Black still could have won here with 2... Re2!, but it is complicated.)
3. Be5 Rg2+
4. Kf1! ½-½ (Dvoretsky 2006:237).
van Wely vs. Nakamura, 2013
abcdefgh
8
h7 black king
h5 white pawn
a4 black bishop
e3 white king
f3 white rook
8
77
66
55
44
33
22
11
abcdefgh
White to move

This 2013 game between Loek van Wely and Hikaru Nakamura was drawn.[8] If White tries 64.Kf4 then after 64...Kh6 65.Rh3 Be8 66.Rh2 Bb5 67.Kf5 Bc4 draws, or 67...Kh7 68.Kg5 Bd3! is a book draw, because the pawn is too far advanced. The game continued

64. Rf6 Be8
65. h6 Bg6
66. Rxg6 Kxg6
67. h7 Kxh7, draw (Benko 2013:44).

In studies

Rauzer

Study by Rauzer, 1928
abcdefgh
8
a6 black circle
e6 white king
b5 black circle
e5 white bishop
h5 black circle
a4 black pawn
c4 black circle
e4 black king
g4 black circle
a3 white pawn
d3 black circle
f3 black circle
8
77
66
55
44
33
22
11
abcdefgh
White to move wins if the black king is on or below the line.

In this 1928 endgame study by Vsevolod Rauzer, White to move can force a win if the black king is on or below the line indicated. Similar positions were studied by Josef Kling and Bernhard Horwitz in 1851 and by Johann Berger in 1921. A very similar position occurred in the Korchnoi-Karpov game above (Griffiths 1992:44–45), (Kasparov 2006:120).

Greco

Greco, 1623
abcdefgh
8
a8 black rook
f5 black bishop
g5 black king
f3 white bishop
f2 white rook
g2 white pawn
h2 white pawn
g1 white king
8
77
66
55
44
33
22
11
abcdefgh
Black to play and draw

The theme is used in this 1623 composition by Gioachino Greco. Black draws:

1...Ra1+
2. Rf1 Rxf1+
3. Kxf1 Bh3!

and Black will sacrifice his bishop for the g-pawn or transform it into an h-pawn after 4. gxh3 (Averbakh 1996:85).

See also

Notes

References

Further reading

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