A ''seriesmover'' is a

chess problem A chess problem, also called a chess composition, is a puzzle set by the composer using chess pieces on a chess board, which presents the solver with a particular task. For instance, a position may be given with the instruction that White is to ...

in which one side makes a series of legal moves without reply at the end of which the other side makes a single move, giving checkmate or yielding stalemate, depending on the precise stipulation. Checks cannot be given except on the last move of the series. There are various types of seriesmover: *Seriesmate: a directmate with White playing a series of moves without reply to checkmate Black (the seriesmover analogue to the directmate). *Serieshelpmate: a

helpmate A helpmate is a type of chess problem in which both sides cooperate in order to achieve the goal of checkmating Black. In a helpmate in ''n'' moves, Black moves first, then White, each side moving ''n'' times, to culminate in White's ''nth'' mov ...

in which Black plays a series of moves without reply after which White plays one move to checkmate Black (the seriesmover analogue to the

). *Seriesselfmate: a

selfmate A selfmate is a chess problem in which White, moving first, must force Black to deliver checkmate within a specified number of moves against their will. Selfmates were once known as sui-mates. Example The problem shown is a relatively simple examp ...

in which White plays a series of moves leading to a position in which Black is forced to give mate (the seriesmover analogue to the

). *Seriesreflexmate: a

reflexmate The problem to the right is a fairly recent example, successful in the World Chess Composing Tournament despite only a single phase of play present. It is by Štefan Sovík and is a reflexmate in two moves. The key is 1.Qh5! and White threatens ...

in which White plays a series of moves leading to a position in which Black can, and therefore must, give mate. Further, White is obliged to mate whenever he can, therefore he has to avoid in his series of moves a position in which he would have mating possibility (the seriesmover analogue to the

). Thus a serieshelpmate in ''n'' moves consists of ''n'' legal unique moves by Black (all but possibly the last non-checking moves) followed by one move by White that mates Black. To the right is a serieshelpmate in seventeen by

Thomas Rayner Dawson Thomas Rayner Dawson (28 November 1889 – 16 December 1951) was an English chess problemist and is acknowledged as "the father of Fairy Chess". He invented many fairy pieces and new conditions. He introduced the popular fairy pieces grassh ...

(published in ''Fairy Chess Review'', 1947). An effective way to solve long serieshelpmates such as this is to envisage a position in which Black ''could'' be checkmated, and then to work out how such a problem could be reached. Here, with just one knight, the only way to checkmate Black is to have the black king in the corner and another black piece on a2, allowing Nb3 giving mate. It might seem there are many ways to do this, but the need to avoid exposing the white king to check means that there is only one. The piece on a2 has to be a

rook Rook (''Corvus frugilegus'') is a bird of the corvid family. Rook or rooks may also refer to: Games *Rook (chess), a piece in chess *Rook (card game), a trick-taking card game Military * Sukhoi Su-25 or Rook, a close air support aircraft * USS ...

, since if it is a queen or bishop, it would cover the b3 square, and if it was a

knight A knight is a person granted an honorary title of knighthood by a head of state (including the Pope) or representative for service to the monarch, the church or the country, especially in a military capacity. Knighthood finds origins in the Gr ...

, it would check the king. The black king needs to walk half-way over the board to avoid the newborn rook giving

check Check or cheque, may refer to: Places * Check, Virginia Arts, entertainment, and media * ''Check'' (film), a 2021 Indian Telugu-language film * ''The Checks'' (episode), a 1996 TV episode of ''Seinfeld'' Games and sports * Check (chess), a thr ...

and then back to a1. (As usual, chess problems with unintended multiple solutions are considered flawed; they are often said to be ''cooked''.) The solution here is: :1.Ka2 2.Ka3 3.Kb4 4.Kc3 5.Kd3 6.Ke2 7.Ke1 8.f1R 9.Rf2 10.Ke2 11.Kd3 12.Kc3 13.Kb4 14.Ka3 15.Ka2 16.Ka1 17.Ra2 Nb3#

References

Chess problems {{Chess-stub