Passed pawn

In chess, a passed pawn is a pawn with no opposing pawns to prevent it from advancing to the eighth rank; i.e. there are no opposing pawns in front of it on either the same file or adjacent files. A passed pawn is sometimes colloquially called a passer. Passed pawns are advantageous because only the opponent's pieces can stop them from promoting.

abcdefgh
8
h6 black pawn
b5 white pawn
e5 white pawn
f5 black pawn
h5 white pawn
c4 white pawn
d4 black pawn
f4 white pawn
g4 white pawn
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abcdefgh
White's pawns on b5, c4, and e5 are passed pawns. Black's pawn on d4 is passed.

In the diagram, the white pawns on b5, c4, and e5 are passed pawns, and Black's pawn on d4 is a passed pawn. If Black plays ...fxg4, then the black pawn on g4 will be passed, as well as White's pawn on f4.

Protected passed pawn

Botvinnik vs. Capablanca, 1938
abcdefgh
8
a7 black pawn
e7 black queen
g7 black king
h7 black pawn
b6 black pawn
e6 white pawn
f6 black knight
g6 black pawn
d5 black pawn
e5 white queen
c4 black pawn
d4 white pawn
b3 black knight
c3 white pawn
g3 white knight
b2 white bishop
g2 white pawn
h2 white pawn
g1 white king
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abcdefgh
White to play

A passed pawn that is protected by its own pawns is called a protected passed pawn. In the first diagram in this article, the pawns on the b- and e-files are protected passed pawns. Two or more passed pawns on adjacent files are called connected passed pawns (see connected pawns), and they are very strong. In the diagram at the top, White's b- and c-pawns are connected passed pawns. A pair of connected passed pawns is sometimes called a steamroller. It is often strategically advantageous for the side with connected passed pawns to place them on the same rank and then advance them in tandem, because this makes them more difficult to blockade.

Sometimes, minor pieces are sacrificed so that a pawn can have a clear path to promotion on the eighth rank. In the example illustrated (Mikhail Botvinnik–José Capablanca, AVRO 1938), in order to capitalize on the passed pawn on e6 and break its blockade by Black's queen, White continued

30. Ba3! Qxa3 31. Nh5+! gxh5 32. Qg5+ Kf8 33. Qxf6+

guaranteeing the e-pawn's promotion. The passed pawn's value is well worth the sacrifice of the bishop in order to clear its path to promotion. The only pieces preventing the e-pawn's promotion are the black queen and knight, and once they are gone, the pawn has a free path to promote. Black's pawns are also helpless to stop it.[1]

Outside passed pawn

Fischer vs. Larsen, 1971
abcdefgh
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e7 black king
f7 black pawn
g6 black pawn
h5 black pawn
a4 white pawn
c3 white king
g3 white pawn
h2 white pawn
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abcdefgh
White to move wins because of the outside passed pawn.

An outside passed pawn is a passed pawn that is separated by several files from the rest of the pawns and deflects the opposing king (and sometimes other pieces) from the defense of its other pawns. Such a pawn often constitutes a strong advantage for its owner because the opposing king does not have the range to cover both sides of the board.

In the diagrammed position from the fifth game of the 1971 Candidates match between Bobby Fischer and Bent Larsen,[2] the outside passed pawn on the a-file confers White a winning advantage, even though material is equal. The pawn will force Black's king to keep it from queening, leaving White's king free to capture Black's remaining pawns and win the game. White wins with:

41. Kd4 Kd6
42. a5 f6
43. a6 Kc6
44. a7 Kb7
45. Kd5 h4

If 45...f5 46.h4 wins.

46. Ke6 1–0[3]
Levenfish & Smyslov, 1957
abcdefgh
8
a8 white rook
g7 black king
a6 white pawn
g6 black pawn
f5 black pawn
h5 black pawn
f4 white pawn
h4 white pawn
a3 black rook
g3 white pawn
f2 white king
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White to play, draw

An outside passed pawn is also powerful in an endgame with minor pieces. It is not so powerful in an endgame with rooks if the opposing rook can get behind the pawn (see diagram), as in the Tarrasch rule.[4][5]

Passed pawns in the endgame

abcdefgh
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f7 black pawn
g7 black pawn
h7 black pawn
f5 white pawn
g5 white pawn
h5 white pawn
g3 black king
g1 white king
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abcdefgh
White, on move, creates a passed pawn and wins.

Passed pawns are particularly important, often of decisive significance, in the endgame. The position illustrated provides a dramatic example of this. White has no passed pawns and seems to be in desperate straits, since Black's king will soon attack White's pawns with ...Kg4. In fact, White by means of a sacrificial combination creates a passed pawn and wins: 1. g6! fxg6 (or 1...hxg6 2.f6! gxf6 3.h6!) 2. h6! gxh6 3. f6! and White's newly created passed pawn will queen. If it is Black's move, he must avoid this combination by playing 1... g6! (not 1...f6 2.h6!, nor 1...h6 2.f6!).

Four examples of advanced passed pawns
Four examples of advanced passed pawns

Since passed pawns have no opposing pawns to stop them, the threat of queening often forces the opponent to use a piece to block or capture the pawn, wasting valuable time and immobilizing material or possibly even losing it (as when a defender of the blocking piece is forced to move). Indeed, the value of a far-advanced passed pawn or pawn group is often equal to or even greater than that of a piece. Four examples of this are seen in the subdivided diagram. In the upper-left quadrant of the board, White's connected passed pawns on the sixth rank are superior to Black's rook. Even if on move, Black cannot stop one of White's pawns from queening. Similarly, in the upper-right quadrant, Black's bishop cannot hold back both of White's pawns. White queens a pawn after 1. f7 (1.h7 also works) Bxf7 2. h7 followed by 3. h8=Q. In the lower-left quadrant, White's queen cannot stop Black's pawn from queening without stalemating Black. The lower-right quadrant highlights how awkward a knight is in dealing with a passed pawn, especially a rook pawn. White's knight is actually worse than useless in trying to stop Black's pawn. It cannot do so itself, and if White's king (which could catch the pawn if the knight were not there) approaches with 1. Kf2 (hoping for 1...hxg2? 2.Kxg2), Black plays 1... h2! and 2... h1=Q.

abcdefgh
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a8 black king
a7 black bishop
c7 white pawn
a6 white king
b6 white pawn
g5 black queen
e1 black knight
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abcdefgh
Position after 9.c7!! White's two connected passed pawns defeat Black's army.

A striking (albeit very unusual) example of the power of passed pawns is seen in the conclusion of an endgame study by Leopold Mitrofanov (see diagram). Black, with a queen, bishop, and knight, is helpless against White's two passed pawns, which threaten both 10.b7# and 10.c8=Q+ Bb8 11.b7#.

  • If 9...Qd5, 10.c8=Q+ Bb8 11.b7+ Qxb7+ 12.Qxb7#
  • If 9...Qg6, 10.c8=Q+ Bb8 11.Qb7#
  • If 9...Qa5+, 10.Kxa5 Kb7 11.bxa7 and Black cannot stop both pawns.

Quotes

  • "A passed pawn is a criminal which should be kept under lock and key. Mild measures, such as police surveillance, are not sufficient." —Aron Nimzowitsch[6]

See also

References

Bibliography

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