Chess problem: Difference between revisions

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{{Short description|A chessChess composition whose solution is a mate or other clear objective}}

{{stack|[[File:An Interesting Problem (Adolphe-Alexandre Lesrel).png|thumb|261px|''An Interesting Problem'', by [[Adolphe Alexandre Lesrel]]]]

|{{Puzzles |Types}}

}}

A '''chess problem''', also called a '''chess composition''', is a [[Chess puzzle|puzzle]] setcreated by the composer using [[chess piece]]s on a [[chesschessboard]] board, which presents the solver with a particular task. For instance, a position may be given with the instruction that White is to move first, and [[checkmate]] Black in two moves against any possible defence. A chess problem fundamentally differs from {{chessgloss|over-the-board}} play in that the latter involves a struggle between Black and White, whereas the former involves a competition between the composer and the solver. Most positions which occur in a chess problem are 'unrealistic' in the sense that they are very unlikely to occur in over-the-board play.<ref name=oz>{{Cite web|url=http://www.ozproblems.com/home|title=OzProblems - Australian chess problem composition|website=www.ozproblems.com}}</ref> There is a goodsubstantial dealamount of [[Glossary of chess problems|specialized jargon used in connection with chess problems]].

{{AN chess|pos=toc}}

==Definition==

The term "'''chess problem"''' is not sharply defined: there is no clear demarcation between chess compositions on the one hand and [[Chess puzzle|puzzles]] or [[Chess tactics|tactical]] exercises on the other. In practice, however, the distinction is very clear. There are common characteristics shared by compositions in the problem section of chess magazines, in specialist chess problem magazines, and in collections of chess problems in book form.<ref name=oz/>

==Features==

Not every chess problem has every one of these features, but most have several:

* The position is ''composed'' – that is, it has not been taken from an actual game, but has been invented for the specific purpose of providing a problem. Although a constraint on orthodox chess problems is that the original position be reachable via a series of legal moves from the starting position, most problem positions would not arise in over-the-board play.{{fact|Today > 90% of published chess puzzles are so on online chess sites, and very many of them are taken from actual games -- often (semi-)automatically chosen by software.}}

* There is a specific ''stipulation'', that is, a goal to be achieved; for example, to checkmate Black within a specified number of moves.

* There is a ''theme'' (or combination of themes) that the problem has been composed to illustrate: chess problems typically instantiate particular ideas.

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**'''Two-movers''': White to move and checkmate Black in two moves against any defence.

**'''Three-movers''': White to move and checkmate Black in no more than three moves against any defence.

**'''[[Grotesque (chess)#Moremover|Moremovers]]More-movers''': White to move and checkmate Black in {{mvar|n}} moves against any defence, where {{mvar|n}} is some particular number greater than three.

**'''Many-movers''': White to move and checkmate Black in a great number of moves. Problems have been composed in which White must mate Black in over 100 moves; the current record for such a composition is over 200 moves. These usually involve frequent repetitions of the same manoeuvre in order to force detrimental pawn advances.

*'''[[Helpmate]]s''': Black to move first cooperates with White to get Black's own king mated in a specified number of moves.

*'''[[Selfmate]]s''': White moves first and forces Black (in a specified number of moves) to checkmate White.

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*'''[[Endgame study|Studies]]''': an orthodox problem in which the stipulation is that White to play must win or draw. Almost all studies are [[Chess endgame|endgame]] positions. Studies are composed chess problems, but because their stipulation is open-ended (the win or draw does not have to be achieved within any particular number of moves) they are usually thought of as distinct from problems and as a form of composition that is closer to the puzzles of interest to over-the-board players. Indeed, composed studies have often extended our knowledge of endgame theory. But again, there is no clear dividing line between the two kinds of positions.

In all the above types of problem, [[castling]] is assumed to be allowed unless it can be proved by [[retrograde analysis]] (see below) that the rook in question or king must have previously moved. ''[[En passant]]'' captures, on the other hand, are assumed {{em|not}} to be legal, unless it can be proved that the pawn to be captured must have moved two squares on the previous move.<ref name="Codex">{{Citationcite web |title=WFCC Codex |url=https://www.wfcc.ch/rules/codex/#c4 |website=World Federation for Chess Composition |access-date=21 July 2025 needed|ref=3}}</ref>

There are several other types of chess problem which do not fall into any of the above categories. Some of these are really coded [[Mathematical chess problem|mathematical problems]], expressed using the geometry and pieces of the chessboard. A famous such problem is the [[knight's tour]], in which one is to determine the path of a knight that visits each square of the board exactly once. Another is the [[Eight queens puzzle|eight queens]] problem, in which eight queens are to be placed on the board so that none is attacking any of the others.

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*'''[[Retrograde analysis|Retrograde analysis problems]]''': such problems, often also called ''retros'', typically present the solver with a diagram position and a question. In order to answer the question, the solver must work out the history of the position, that is, must work backwards from the given position to the previous move or moves that have been played.<ref>{{cite book |author=Smullyan, R. |year=1994 |title=Chess Mysteries of Sherlock Holmes: Fifty tantalizing problems of chess detection |publisher=Random House |series=Puzzles & Games |ISBN=978-0-8129-2389-6}}</ref> A problem employing retrograde analysis may, for example, present a position and ask questions like "What was White's last move?", "Has the bishop on c1 moved?", "Is the black knight actually a promoted pawn?", "Can White castle?", etc. Some retrograde analysis may also have to be employed in more conventional problems (directmates and so on) to determine, for example, whether an ''en passant'' pawn capture or castling is possible. The most important subset of retro problems are:

**'''[[Proof game|Shortest proof game]]s''': the solver is given a position and must construct a game, starting from the normal game array, which ends in that position. The two sides cooperate to reach the position, but all moves must be legal. Usually the number of moves required to reach the position is given, though sometimes the task is simply to reach the given position in the smallest number of moves.

*'''Construction tasks''': no diagram is given in construction tasks; instead, the aim is to construct a game or position with certain features. For example, [[Sam Loyd]] devised the problem: "Construct a game which ends with black delivering discovered checkmate on move four" (published in ''Le Sphinx'', 1866 – the solution is 1.f3 e5 2.Kf2 h5 3.Kg3 h4+ 4.Kg4 d5#); while all White moves are unique (see [[#Beauty in chess problems]]|Beauty in chess problems]]), the Black ones are not. A unique problem is: "Construct a game with black b-pawn checkmating on move four" (from ''Shortest construction tasks map'' in [[#External links|External links]] section; the unique solution is 1.d4 c6 2.Kd2 Qa5+ 3.Kd3 Qa3+ 4.Kc4 b5#). Some construction tasks ask for a maximum or minimum number of effects to be arranged, for example a game with the maximum possible number of consecutive discovered checks, or a position in which all sixteen pieces control the minimum number of squares. A special class are games uniquely determined by their last move like "3...Rxe5+" or "4...b5#" from above.

Across most of the above genres, there is great interest in exploring [[fairy chess]], in which non-standard boards, pieces or rules apply.

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*The problem should be economical.<ref>Iqbal, A. (2008). Evaluation of Economy in a Zero-sum Perfect Information Game, The Computer Journal, Oxford University Press, Vol. 51, No. 4, pp. 408–418, {{doi|10.1093/comjnl/bxm060}}. Online ISSN 1460-2067, Print ISSN 0010-4620. http://comjnl.oxfordjournals.org/content/51/4/408.abstract {{Webarchive|url=https://web.archive.org/web/20160608122007/http://comjnl.oxfordjournals.org/content/51/4/408.abstract |date=2016-06-08 }}</ref> There are several facets to this desideratum. For one thing, every piece on the board should serve a purpose, either to enable the actual solution, or to exclude alternative solutions. Extra units should not be added to create "red herrings" (this is called ''dressing the board''), except in rare cases where this is part of the theme. If the theme can be shown with fewer total units, it should be. For another, the problem should not employ more moves than is needed to exhibit the particular theme(s) at its heart; if the theme can be shown in fewer moves, it should be.

==Example problemExamples==

{{Chess diagram

| tright

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The key move is 1.Rh1. This is difficult to find because it makes no threat – instead, it puts Black in [[zugzwang]], a situation in which the player must move, yet every move leads to a disadvantage. Each of Black's nineteen legal replies allows an immediate mate. For example, if Black defends with 1...Bxh7, the d5-square is no longer guarded, and White mates with 2.Nd5#. Or if Black plays 1...Re5, Black blocks that escape square for his king allowing 2.Qg4#. If Black plays 1...Rf6, then 2.Rh4#. Yet if Black could only pass (i.e., make no move at all), White would have no way to mate on his second move. The full solution is as follows:

:1 Rh1{{chesspunc|!}} and now:

::1...Bxh7, 2.Nd5# (unguards d5)

::1...Bf7, 2.Qf5# (interferes with rook’s guard of f5)

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| White mates in one move!

}}

Although mostSome problems call for straightforward (though possibly difficult) solution, occasionally a problem will involve a humorous trick or twist. The problem atto the right, shown in Norwegian broadcaster [[NRK]]'s airings from the World Championships in Dubai 2021, calls for White to move and give immediate checkmatemate in just a singleone move. The trick is to recognize that despite the arrangement of the Black men, the board is actually viewed from the White side, (as shown by the Blackblack king standing on a square of its own color, rather than on the opposite color as in the standard opening position). Thus the solution is 1 .Nd3#; the Blackknight pawns are movingis ''downbehind'' the boardblack pawns and cannot capturebe the White knightcaptured.

Although most problems call for straightforward (though possibly difficult) solution, occasionally a problem will involve a humorous trick or twist. The problem at right, shown in Norwegian broadcaster [[NRK]]'s airings from the World Championships in Dubai 2021, calls for White to move and give immediate checkmate in just a single move. The trick is to recognize that despite the arrangement of the Black men, the board is actually viewed from the White side (as shown by the Black king standing on a square of its own color, rather than on the opposite color as in the standard opening position). Thus the solution is 1 Nd3#; the Black pawns are moving ''down'' the board and cannot capture the White knight.

==Abbreviations==

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==Titles==

Just as in over-the-board play, the titles [[Grandmaster (chess)|International Grandmaster]], [[FIDE Titles|International Master]] and [[FIDE Titles|FIDE Master]] are awarded by FIDE via the [[Permanent Commission of the FIDE for Chess Compositions]] (PCCC) for especially distinguished problem and study composers and solvers (unlike over-the-board chess, however, there have not been any women-only equivalents to these titles in problem chess).

For composition, the International Master title was established in 1959, with [[André Chéron (chess player)|André Chéron]], [[Arnoldo Ellerman]], [[Alexander Gerbstmann]], [[Jan Hartong]], [[Cyril Kipping]] and [[Marian Wróbel]] being the first honorary recipients. In subsequent years, qualification for the IM title, as well as for the GM title (first awarded in 1972 to [[Genrikh Gasparyan|Genrikh Kasparyan]], [[Lev Loshinsky]], [[Comins Mansfield]], and [[Eeltje Visserman]]) and the FM title (first awarded 1990) has been determined on the basis of the number of problems or studies a composer had selected for publication in the [[FIDE Album]]s. These albums are collections of the best problems and studies composed in a particular three-year period, as selected by FIDE-appointed judges from submitted entries. Each problem published in an album is worth 1 point; each study is worth 1⅔{{frac|1|2|3}}; joint compositions are worth the same divided by the number of composers. For the FIDE Master title, a composer must accumulate 12 points; for the International Master title, 25 points are needed; and for the Grandmaster title, a composer must have 70 points.

For solvers, the GM and IM titles were both first awarded in 1982; the FM title followed in 1997. GM and IM titles can only be gained by participating in the official World Chess Solving Championship (WCSC): to become a GM, a solver must score at least 90 percent of the winner's points and on each occasion finish in at least tenth place three times within ten successive WCSCs. For the IM title they must score at least 80 percent of the winner's points and each time finish in at least fifteenth place twice within five successive WCSCs; alternatively, winning a single WCSC or scoring as many points as the winner in a single WCSC will earn the IM title. For the FM title, the solver must score at least 75 percent of the winners points and each time finish within the top 40 percent of participants in any two PCCC-approved solving competitions.

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==See also==

* [[Chess composer]]

* [[Glossary of chess problems]]

* [[Chess aesthetics]]

* [[Software for handling chess problems]]

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*[[Andrei Frolkin|Frolkin, Andrei]] and [[Gerd Wilts|Wilts, Gerd]] (1991), ''Shortest Proof Games''. A collection of 170 proof games (published in Germany, but written in English).

*[[Kenneth S. Howard|Howard, Kenneth S.]] (1961), ''How To Solve Chess Problems'', Dover Publications. {{ISBN|0-486-20748-X}}. A preliminary section of 30 pages is a useful introduction for novice solvers; there follow 112 problems with discussion.

*[[Michael Lipton|Lipton, Michael]], [[Robin Matthews (economist)|Matthews, R. C. O.]] and [[John M. Rice (chess composer)|Rice, John]] (1963), ''Chess Problems: Introduction to an Art'', Faber.

*[[Jeremy Morse|Morse, Jeremy]] (1995; revised edition, 2001), ''Chess Problems: Tasks and Records'', Faber and Faber. {{ISBN|0-571-15363-1}}. Concentrates on maximum tasks and records.

*[[John Nunn|Nunn, John]] (1985), ''Solving in Style'', Gambit Publications. {{ISBN|1-901983-66-8}}. Problems seen from the point of view of the solver.

*[[John M. Rice (chess composer)|Rice, John]] (1996), ''Chess Wizardry: The New ABC of Chess Problems'', Batsford / International Chess Enterprises. {{ISBN|1-879479-33-8}}. A general overview of chess problems, including an extensive A–Z of themes and terms, and 460 problems. Widely regarded as the best single-volume work in English on the subject.

*[[Milan Velimirovic|Velimirovic, Milan]] and [[Kari Valtonen|Valtonen, Kari]] (2012), ''The definitive book - Encyclopedia of Chess Problems: Themes and Terms'', Chess Informant. {{ISBN|978-86-7297-064-7}}. An extensive overview A–Z of themes and terms with 1726 problems.