Qb8+ and the position on the right is reached. Then the cross-check 135.Qee8+ (or Qfe8+) forks the king and queen, forces an exchange, and wins the game. Anderson problem, 1919 Cross-checks are relatively infrequent in actual play, but are popular in chess problems since they make for a relatively unobvious solution. In the problem shown to the right, White is to move and mate in two moves against any defence. It is by G.F. Anderson and was first published in Il Secolo in 1919. The key 1.Kd6, threatening 2.Qb7#, gives the black king two flight squares, and two of the variations exploit these: 1...Kb6 2.Bc2# and 1...Kb4 2.Kxc6#. The other two defences exploit the fact that the key exposes the white king to checks, and are answered by cross-checks: 1...Rg6+ 2.Be6# and 1...Rd3+ 2.Bd5#. Anderson problem, 1961 The problem to the right, also by G. F. Anderson (first published in The Observer in 1961) and also a mate in two, features no fewer than five cross-checks. The key is 1.Qb6 (threat: 2.Ne4#), with the following variations: 1...exf6+ 2.Nb7# 1...exd6+ 2.Nd7# 1...Nd4+ 2.Rf5# 1...Nxd6+ 2.Nd3# 1...Nf-other+ 2.Ne4# 1...Kxf6 2.Qb2# 1...Kxd6 2.Rd4# See also Pawnless chess endgame References Bibliography Further reading John Rice, Chess Wizardry: The New ABC of Chess Problems (London, Batsford, 1996) External links Three successive cross-checks in a game Chess terminology Chess problems Chess tactics