Transposition (chess)
Encyclopedia
A transposition in chess
is a sequence of moves that results in a position which may also be reached by another, more common sequence of moves. Transpositions are particularly common in opening
, where a given position may be reached by different sequences of moves. Players sometimes use transpositions deliberately in order to avoid variations they dislike, lure opponents into unfamiliar or uncomfortable territory or simply to worry opponents.
In chess the verb "transpose" means shifting the game on to a different opening track from that on which it started.
Transposition table
s are an essential part of a computer chess
program.
:
But this position can also be reached from the English Opening
:
so the English Opening has transposed into the Queen's Gambit.
The second position shows another example. The position can arise from the French Defence
.
The identical position can also be reached, with two extra moves played by each side, from the Petrov Defense:
and Sicilian Defence
.
For a simple example, the opening moves 1. d4 e6 can transpose very quickly into a wide range of openings, including:
Chess
Chess is a two-player board game played on a chessboard, a square-checkered board with 64 squares arranged in an eight-by-eight grid. It is one of the world's most popular games, played by millions of people worldwide at home, in clubs, online, by correspondence, and in tournaments.Each player...
is a sequence of moves that results in a position which may also be reached by another, more common sequence of moves. Transpositions are particularly common in opening
Chess opening
A chess opening is the group of initial moves of a chess game. Recognized sequences of opening moves are referred to as openings as initiated by White or defenses, as created in reply by Black. There are many dozens of different openings, and hundreds of named variants. The Oxford Companion to...
, where a given position may be reached by different sequences of moves. Players sometimes use transpositions deliberately in order to avoid variations they dislike, lure opponents into unfamiliar or uncomfortable territory or simply to worry opponents.
In chess the verb "transpose" means shifting the game on to a different opening track from that on which it started.
Transposition table
Transposition table
In computer chess and other computer games, transposition tables are used to speed up the search of the game tree. Transposition tables are primarily useful in perfect information games, meaning the entire state of the game is known to all players at all times....
s are an essential part of a computer chess
Computer chess
Computer chess is computer architecture encompassing hardware and software capable of playing chess autonomously without human guidance. Computer chess acts as solo entertainment , as aids to chess analysis, for computer chess competitions, and as research to provide insights into human...
program.
Positions reached by different routes
For instance, the first position can be obtained from the Queen's GambitQueen's Gambit
The Queen's Gambit is a chess opening that starts with the moves:The Queen's Gambit is one of the oldest known chess openings. It was mentioned in the Göttingen manuscript of 1490 and was later analysed by masters such as Gioachino Greco in the seventeenth century...
:
- 1. d4 d5
- 2. c4 e6
- 3. Nc3 Nf6
But this position can also be reached from the English Opening
English Opening
In chess, the English Opening is the opening where White begins:A flank opening, it is the fourth most popular and, according to various databases, anywhere from one of the two most successful to the fourth most successful of White's twenty possible first moves. White begins the fight for the...
:
- 1. c4 Nf6
- 2. Nc3 e6
- 3. d4 d5
so the English Opening has transposed into the Queen's Gambit.
The second position shows another example. The position can arise from the French Defence
French Defence
The French Defence is a chess opening. It is characterised by the moves:The French has a reputation for solidity and resilience, though it can result in a somewhat cramped game for Black in the early stages...
.
- 1. e4 e6
- 2. d4 d5
- 3. exd5 exd5
- 4. Nf3 Nf6
The identical position can also be reached, with two extra moves played by each side, from the Petrov Defense:
- 1. e4 e5
- 2. Nf3 Nf6
- 3. Nxe5 d6
- 4. Nf3 Nxe4
- 5. d3 Nf6
- 6. d4 d5
Transposition possibilities of some openings
Some openings are noted for their wide range of possible transpositions, for example the Catalan OpeningCatalan Opening
The Catalan is a chess opening which can be considered to be White adopting a mixture of the Queen's Gambit and Réti Opening: White plays d4 and c4 and fianchettoes the white bishop on g2. A common opening sequence is 1.d4 Nf6 2.c4 e6 3.g3 d5 4.Bg2, though the opening can arise from a large number...
and Sicilian Defence
Sicilian Defence
The Sicilian Defence is a chess opening that begins with the moves:The Sicilian is the most popular and best-scoring response to White's first move 1.e4...
.
For a simple example, the opening moves 1. d4 e6 can transpose very quickly into a wide range of openings, including: