This article uses algebraic notation to describe chess moves.

Promotion is a chess term describing the transformation of a pawn that reaches its eighth rank into the player's choice of a queen, knight, rook, or bishop of the same color (Just & Burg 2003:16). The new piece replaces the pawn on the same square and is part of the move. Promotion is not limited to pieces that have already been captured (Schiller 2003:18-19). Every pawn that reaches its eighth rank must be promoted. Pawn promotion often decides the result of a chess endgame.

Chessboard with extra black and white queen for promotion at 35th Chess Olympiad

Since the queen is the most powerful piece, the vast majority of promotions in practical play are to a queen. Promotion to a queen is often referred to as queening. A promotion to a piece other than the queen is called underpromotion (Golombek 1977).

Promotions to king are allowed in some chess variants, such as suicide chess. As noted below, at one time promotion was not mandatory, and the player could choose to have a pawn reaching the eighth rank remain a pawn. In some fairy chess variants, promotions to pieces of the opponent's color are also possible.

[edit] Promotion to various pieces

Promotion to a queen is the most common in practical play, since the queen is the most powerful piece. Underpromotion (promoting to a piece other than a queen) occurs more often in chess problems than in practical play. In practical play, underpromotions are rare, but not extraordinarily so (see table below); as the most powerful piece, the queen is usually the most desirable, but promotion to a different piece can be advantageous in certain situations. A promotion to knight is occasionally useful, particularly if it occurs with check. A promotion to a rook is, on rare occasions, necessary in order to avoid stalemate. Promotion to a bishop almost never occurs in practical play (about one game in 33,000). (See Underpromotion: Promotion to rook or bishop for examples of underpromotions to rook and bishop made in order to avoid stalemate.)

It should be noted that the percentage of games involving one or more promotions can be misleading due to the fact that often a resignation will occur prior to an actual promotion (Colusso vs. Calvaneso, 2008). In the 2006 ChessBase database of 3,200,000 games (many grandmaster- and master-level), about 1.5 percent of the games contain a promotion. In these games (counting games in which multiple promotions by the same player to the same piece occur only once), the fraction of times each piece was promoted to is approximately:

Fischer-Petrosian 1959

Position after 37. h8(Q), four queens

This suggests that about 3 percent of all promotions are underpromotions. The frequency of truly significant underpromotions is, however, less than this. Note that the promotion is not limited to pieces that have been captured. Some chess sets (see Chess piece) come with an extra queen of each color to use for promoted pawns. If no queen is available, an upside-down rook is often used to designate a queen.

The diagram from the game between Bobby Fischer and Tigran Petrosian in the 1959 Candidates Tournament shows a position in which each side has two queens.^[1] Four queens existed from move 37 until move 44 (Fischer 2008:113-14).

[edit] Strategy

The ability to promote is often the critical factor in endgames and thus is an important consideration in opening and middlegame strategy. Almost all promotions occur in the endgame, but promotion in the middlegame does happen.

Promotion occasionally occurs even in the opening, often after one side makes a blunder, as in the Lasker trap, which features an underpromotion to a knight on move seven: 1.d4 d5 2.c4 e5 3.dxe5 d4 4.e3? Bb4+ 5.Bd2 dxe3! 6.Bxb4?? exf2+! 7.Ke2 fxg1(N)+! Schlechter-Perlis, Karlsbad 1911 could have featured a promotion to queen on move 11: 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.e3 Bf5 5.Qb3 Qb6 6.cxd5 Qxb3 7.axb3 Bxb1? 8.dxc6! Be4?? 9.Rxa7! Rxa7 10.c7 threatening both 11.cxb8(Q) and 11.c8(Q).^[2] Perlis avoided the trap with 8...Nc6!, losing more slowly.^[3] The British grandmaster Joe Gallagher pulled off a similar idea a half-move earlier in Terentiev-Gallagher, Liechtenstein Open 1990: 1.d4 Nf6 2.Bg5 Ne4 3.Bf4 c5 4.c3 Qb6 5.Qb3 cxd4 6.Qxb6 axb6 7.Bxb8? dxc3 8.Be5?? Rxa2! and now White could have resigned, since if 9.Rxa2, c2 promotes (Gallagher 1996:121). Another example occurs after 1.e4 c6 2.d4 d5 3.Nc3 dex4 4.Nxe4 Nf6 5.Ng3 h5 6.Bg5?! h4 7.Bxf6?? hxg3 8.Be5 Rxh2! 9.Rxh2 Qa5+! 10.c3 Qxe5+! 11.dxe5 gxh2, with the dual threat of 12...hxg1(Q) and 12...h1(Q), as in Schuster-Carls, Bremen 1914 and NN-Torre, Mexico 1928 (Burgess 1998:72). Note that 10.Qd2 (instead of 10.c3) would have been met by 10...exf2+! 11.Kd1 (11.Kxf2 Qxd2+) Qxd2+ 12.Kxd2 fxg1(Q) rather than 10...Qxe5 11.dxe5 gxh2 12.Nf3 h1(Q) 13.0-0-0 with a strong attack (Neishtadt 1996:94-96).

P. Short-Daly, Irish championship 2006

Position after White's 10th move

There are also a few opening lines where each side gets a desperado pawn that goes on a capturing spree, resulting in each side queening a pawn in the opening. An example is seen in the position at right, where play continued 10...bxc3 11.exf6 cxb2 12.fxg7 bxa1(Q) 13.gxh8(Q).

Both players promoted by White's seventh move in Casper-Heckert: 1.e4 Nf6 2.Nc3 d5 3.e5 d4 4.exf6 dxc3 5.d4 cxb2 6.fxg7 bxa1(Q) 7.gxh8(Q).^[4]

[edit] History of the rule

The original idea was that a foot soldier that advanced all the way through the enemy lines was promoted to the lowest officer. In medieval ages, the weakest piece was the queen, or farzin, due to its limited move at the time. When the queen acquired its new movement, the game was radically altered. When the fers became the queen, there were objections that a king should not have more than one queen (Davidson 1981:59-60).

At different times, the pawn could only promote to the piece of the file on which it promoted, or on which it started. In Italy in the 18th and early 19th century, the pawn could only be promoted to a piece that had already been captured. Likewise, Philidor did not like the possibility of having two queens, and in all editions of his book (1749 to 1790) he stated that a promotion could only be to a piece previously captured. Lambe also stated this rule in a 1765 book (Davidson 1981:60-61). If none of the promoting player's pieces had yet been captured, the pawn remained inactive until one of the player's pieces was captured, whereupon the pawn immediately assumed that role (Staunton 1848:7). A player could thus never have two queens, three knights, three rooks, or two bishops of the same color on the board (Staunton 1848:7).

The restricted promotion rule was used unevenly. Arthur Saul published a book in 1814 which gave the unrestricted promotion rule, as did Jacob Sarratt in an 1828 book. By Sarratt's time, the unrestricted promotion was popular, and according to Davidson it was universal by the mid-19th century (Davidson 1981:61). However, Howard Staunton wrote in The Chess-Player's Handbook, originally published in 1847, that according to Carl Jaenisch the restricted promotion rule then remained in force in northern Europe, Russia, Scandinavia, and Germany(Staunton 1848:7).

[edit] 1862 British Chess Association rule

Although the current rules of chess require a pawn that reaches the eighth rank to be promoted to a different piece, that was not always the case. Wilhelm Steinitz, the first World Champion, in his 1889 work The Modern Chess Instructor endorsed the then-existent "Code of Laws of the British Chess Association" (Steinitz 1990:xx). Law XIII thereof provided, "When a pawn has reached the eighth square, the player has the option of selecting a piece, whether such piece has previously been lost or not, whose names and powers it shall then assume, or of deciding that it shall remain a pawn.^[5] Steinitz explained the purpose of this rule by referring to the position diagrammed at left, which he cited from Johann Löwenthal's Book of the London Chess Congress, of 1862:

White to move

White to play and mate in one

If White plays 1.bxa8(Q)?? (or any other promotion), Black wins with 1...gxh3, when White cannot stop Black from checkmating him next move with 2...h2#. Instead, White draws by 1.bxa8(P)!!, when 1...gxh3 or 1...Kxh3 stalemates White, and other moves allow 2.Bxg2, with a drawn endgame.^[6] Steinitz wrote, "We approve of the decision of the London Chess Congress, of 1862, although the 'dummy' pawn rule was denounced by some authorities."^[7] The same rule and explanation are given by George H. D. Gossip in The Chess-Player's Manual (Gossip & Lipschütz 1902:17-18, 33).

After 1. bxa8(P) Kxh3 stalemate

The broad language of Law XIII also appears to allow promotion to any piece of any color. This led to the whimsical endgame study diagrammed at right. White is to play and checkmate in one move. No solution is possible under modern-day rules, but with Law XIII in effect the surprising solution is 1.g8(Black N)!, when the newly promoted knight blocks its own king's flight square (Birbrager 1975:25). Presumably other amusing problems could be created involving promotion to a white or black king, which Law XIII also appears to allow.

Howard Staunton vigorously opposed the 1862 rule when it was proposed, but the tournament committee passed it by a large majority of votes (Sergeant 1934:117). However, it did not catch on. Philip Sergeant wrote (Sergeant 1934:138):

A correspondent in the May [1865] Chess World ... did not exaggerate when he wrote that the B.C.A. Code had been very generally rejected by British amateurs, and emphatically condemned by the leading authorities of America, Germany, and France. In particular, the absurd "dead Pawn" rule, against which Staunton had made his protest in 1862, had failed to win acceptance.

The tournament book of the London 1883 international chess tournament (originally published in 1883) contains a "Revised International Chess Code", which was "published for the consideration of Chess Players, and especially of the managers of future International Tournaments". Unlike the 1862 rule, which allowed the pawn to remain a pawn, it requires that, "A Pawn reaching the eighth square must be named as a Queen or piece ... ."^[8] (Minchin 1973:iii-iv)

[edit] Underpromotion

Promotion to a knight, bishop, or rook is an "underpromotion".

[edit] Promotion to a knight

Promotion to a knight wins

Since the knight moves in a way which the queen cannot, knight underpromotions can be very useful, and are the most common type of underpromotion.

In the top diagram on the right, given by World Champion Emanuel Lasker, White has a huge material disadvantage. Promotion to a queen (by 1.exd8(Q)?) would still leave Black ahead in material. Instead, promotion to a knight with 1.exd8(N)+! wins by virtue of a fork: 1....K any 2.Nxf7 followed by 3.Nxh8 leaves White a piece up with a winning endgame.^[9]

Kamsky-Bacrot, 2006

Position before 74... e1N+, promotion to a knight gets to a drawn endgame

Promotion to knight may also be done for defensive reasons; to the right is such a case, a 2006 game between Gata Kamsky and Etienne Bacrot.^[10] White threatens to capture the pawn or checkmate by Rh1 if the black pawn promotes to a queen, rook, or bishop. The only move that does not lose for Black is 74...e1N+! The resulting rook versus knight endgame is a theoretical draw (see pawnless chess endgame). In the actual game, mistakes were made in the rook versus knight endgame and White won on move 103 (de la Villa 2008:43-44). This is a standard defensive technique for the endgame of a rook versus a pawn (de la Villa 2008:71-72).

Zurakhov-Koblentz, Tbilisi 1956

Position after Black's 56th move

Position after Black's 78th move

Tim Krabbé points out that Zurakhov-Koblentz (pictured in the diagrams at left and right) furnishes a very rare example of a game with two "serious" underpromotions to knight. In the position at left, Black threatens 57...Nxg7, and if White avoided this by promoting to queen, rook, or bishop, Black would reach a drawn position with 57...Ne7+! and 58...Nxg8. The only winning move is 57.g8N! Krabbé notes that this is a rare example of a non-checking knight-promotion.

Twenty-one moves later, the players reached the position at right. Once again, a promotion to anything other than a knight would be a blunder allowing a knight fork, e.g. 79.c8Q?? Nd6+ and 80...Nxc8, with a drawn ending. White instead played 79.c8N+! (Here, there are other winning moves, such as 79.Kc5.) Kb8 80.Kb6 and Black resigned, since White cannot be stopped from promoting a third pawn—this time to a queen.

White to play and win

This was the 71st move of a game V.Akopian v. S.Karjakin at Nalchik, 2009^[11]. 71.a8Q, QxP+ would let the Black Queen and the White King alternate between the a-file and the b-file with perpetual check, so Akopian played 71.a8N, and Karjakin resigned, as, if 71...QxP+; 72.Nb6+ covers the check and forces 72...QxN; 73.KxQ, and Akopian is a Queen up and wins easily.

[edit] Promotion to rook or bishop

Because the queen combines the powers of the rook and the bishop, there is rarely a reason to underpromote to either of those pieces. However, doing so is occasionally advantageous, usually to avoid stalemate:

Promotion to a rook wins

P. Short-Daly, Irish championship 2006

Position after White's 70th move

In the position at left (with White to move), Black threatens to capture White's pawn, and a promotion to queen would be stalemate. Only 1.g8(R)! wins.

At right is a position from a 2006 game at the Irish Chess Championship.^[12] Here too, a promotion to queen would allow stalemate: 70...b1(Q)?? 71.Qh3+! Kxh3 stalemate. Instead, the game concluded 70...b1(R)! 0-1

White to play and win

In the position at left, promotion to bishop is the only winning move: 1. c8(B)! B\any 2. Nd7 B\any 3. Bb7# 1-0

Herman Mattison
Rigaer Tageblatt, 1914

White to move and draw. Position after fifth move

Less often, underpromotion to bishop or rook may be necessary not to avoid stalemate, but to induce it and thus save a draw in an otherwise hopeless position. To the right is an example from the end of a study by Herman Mattison.

Both king moves lose quickly (they can be met by ...Rgg7, for example), so the pawn must be promoted. 6.b8Q and 6.b8R both lose to a capture on c8, and 6.b8N, while leaving a stalemate after 6...Rgxc8??, loses quickly after 6...Rcxc8. This only leaves 6.b8B!: since the c7 rook is now pinned, Black must either lose it with a theoretical draw or play 6...Rgxc8 which, with a bishop on b8 rather than a queen or rook, is stalemate.

Underpromotion to knight or rook in practical play is rare, and to bishop is even rarer, but in composed chess problems such as this last example, it occurs more often. Perhaps the most famous example is the Saavedra position. Some cases can be quite spectacular: a study by Jan Rusinek, for example, sees White promoting to knight, bishop and rook in order to induce stalemate. An Allumwandlung is a problem where promotions to all four possible pieces occur. An extreme example is the Babson task, where underpromotions by black are countered by matching underpromotions by white (so if black promotes to a rook, so does white, and so on), white's underpromotions being the only way to mate black in the stipulated number of moves.

Reshko-Kaminsky, 1972

1.a8(B)! is the only way to win

In the 1972 game^[13] between Aron Reshko and Oleg Kaminsky, promotion to a queen or rook would allow 1...Qf7+!! 2.Qxf7 stalemate. White could promote to a knight, but that would not be sufficient to win (Soltis 1978:34-35). White wins after:

1.a8(B)! Qb3

2.Qd7 2.Bc6 Qa2 3.Bd7 Qg8 4.Qxg8+ Kxg8 5.Kg6 also wins (Müller & Pajeken 2008:219-20)

2...Qg8

3.Bd5 Qf8

4.Bf7 Kh8

5.Qe8 Qxe8

6.Bxe8 Kh7

7.Bf7 Kh8 Black is in zugzwang for two moves.

8.Kg6 h5

9.Kxh5 1-0

In the actual game, White promoted to a knight. White won the game because of an error by Black (Müller & Pajeken 2008:219-20).

[edit] Insignificant underpromotions

Shirov vs. Kramnik, 2005

Position before 25... e1(B)+

A majority of underpromotions in practical play are, as Tim Krabbé puts it, "silly jokes"—underpromotions made where there is no real need to do so (see External links below). A recent high-level example was the game Shirov-Kramnik, Amber Blindfold, 2005.^[14] In the position shown to the left, Black played 25...e1B+. This underpromotion is completely inconsequential as both it and 25...e1Q+ force 26.Qxe1.

Vidmar vs. Maróczy, 1932

Position before 124. h8(B)+ Kxh8 125. d8(B)

In 1932, a long game^[15] between Milan Vidmar and Géza Maróczy had been a theoretical draw for many moves, because of the opposite-colored bishops endgame. Two underpromotions to bishops occurred on successive moves by White:

124. h8=B+ Kxh8

125. d8=B Kxg8

The game was drawn on move 129.

[edit] Articles on promotions in certain endgames

• King and pawn versus king endgame promoting the pawn in a king and pawn versus king ending, if possible.
• Rook and pawn versus rook endgame promoting the pawn in a rook and pawn versus rook ending, if possible.
• Queen versus pawn endgame
• opposite-colored bishops endgame

[edit] See also

• Lasker Trap—an opening trap that features an underpromotion on the seventh move.
• Chess endgame—Endgames usually hinge on promotion
• Allumwandlung
• Babson task
• Saavedra position
• Rules of chess
• Pawn (chess)
• Chess piece

[edit] Notes

[edit] References

• Birbrager, I. (1975), Chess: Serious; for Fun, CHESS Ltd. 
• Burgess, Graham (1998), The Quickest Chess Victories of All Time, Cadogan Books, ISBN 1-85744-538-4 
• Davidson, Henry (1981), A Short History of Chess (1949), McKay, ISBN 0-679-14550-8 
• de la Villa, Jesús (2008), 100 Endgames You Must Know, New in Chess, ISBN 978-90-5691-244-4 
• Fischer, Bobby (2008), My 60 Memorable Games (1969), Batsford, ISBN 978-1-906388-30-0 
• Gallagher, Joe (1996), Beating the Anti-King's Indians, Batsford/International Chess Enterprises, ISBN 1-879479-36-2 
• Golombek, Harry (1977), Golombek's Encyclopedia of Chess, Crown Publishing, ISBN 0-517-53146-1 
• Gossip, G. H. D.; Lipschütz, S. (1902), The Chess-Player's Manual, David McKay 
• Hooper, David; Whyld, Kenneth (1992), The Oxford Companion to Chess (second ed.), Oxford University Press, ISBN 0-19-866164-9 
• Just, Tim; Burg, Daniel B. (2003), U.S. Chess Federation's Official Rules of Chess (fifth ed.), McKay, ISBN 0-8129-3559-4 
• Minchin, J.I. (editor) (1973), Games Played in the London International Chess Tournament 1883 (third ed.), British Chess Magazine, SBN 90084608-9 
• Müller, Karsten; Pajeken, Wolfgang (2008), How to Play Chess Endings, Gambit Publications, ISBN 978-1-904600-86-2 
• Neishtadt, Iakov (1996), Winning Quickly with Black, Cadogan Books, ISBN 1-85744-039-0 
• Schiller, Eric (2003), Official Rules of Chess (second ed.), Cardoza, ISBN 978-1-58042-092-1 
• Sergeant, Philip W. (1934), A Century of British Chess, David McKay, OCLC 1835573 
• Soltis, Andy (1978), Chess to Enjoy, Stein and Day, ISBN 0-8128-6059-4 
• Staunton, Howard (1848), The Chess-Player's Handbook (second ed.), Henry C. Bohn 
• Steinitz, Wilhelm (1990), The Modern Chess Instructor (1889, reprinted 1990), Edition Olms AG, Zürich, ISBN 3-283-00111-1 

[edit] External links

• Examples of underpromotion in practical play from Tim Krabbé