Retrograde analysis

Friedrich Amelung

Düna newspaper , 1897

Example of a retro: mate in 2 moves

	a	b	c	d	e	f	G	H
8th									8th
7th									7th
6th									6th
5									5
4th									4th
3									3
2									2
1									1
	a	b	c	d	e	f	G	H

Black's last move could only have been g7 – g5. This enables mate in 2 moves with 1. hxg6 ep Kh5 2. Rxh7 #.

In chess problems , retrograde analysis (or retroanalysis for short ) is often used as a technique to determine which moves were previously played to achieve a particular position. While this technique is seldom needed to solve common chess problems, there are a number of chess problems of which it is an important part; Such problems are called retros , and the whole discipline is called retro chess .

description

So-called chess retros can partly have the same task as normal chess problems and, for example, ask for a mate in two moves. But the real puzzle is then to determine the history of a position, for example to clarify the possibility of castling or an en passant capture. According to the conventions for chess compositions, the position must be legal, i.e. theoretically accessible by regular moves from the starting position. Castling is considered permissible if it cannot be proven by retroactive analysis that the rook or king has already moved. The en-passant stroke is only allowed if it can be proven by retro-analysis that the last move was a double move by a pawn. Illegal positions are considered incorrect, and the legality check is also carried out with the help of retroanalysis.

Other problems may raise questions specific to the history of a position, such as "Can the bishop on c1 the result of the conversion to be a farmer?". This is essentially a matter of logical reasoning with a high appeal to puzzle enthusiasts.

See also

• Chess composition
• Endgame database

literature

• Raymond M. Smullyan : Chess with Sherlock Holmes. 50 exciting problems. Ravensburger Buchverlag G , Ravensburg 1986, ISBN 978-3473431175 .
• Raymond Smullyan : The Caliph's Chess Secrets. New problems in retro-analysis. Maier , Ravensburg 1984, ISBN 978-3473431892 .

Web links

• The retrograde analysis in 3500 examples on janko.at
• All about retro analysis on thbrand.de
• What is retro chess on herderschach.de
• Retro chess at SV Springer Recklinghausen-Süd

Individual evidence

1. ↑ En Passant Capture ( accessed July 27, 2019)