Each of these 125 problems has won top prize in one of the many chess competitions held throughout the world-and they will help hone players' skills so that even beginners can learn to become winners too. As with all orthodox chess conundrums, the ones collected here stipulate that White makes the first move, and must checkmate Black in a specified number of moves no matter what Black does. This specification is inviolable: players can neither make more moves nor fewer, and each problem has only one correct key. A section offers hints for the really, truly stumped. But beware: while most hints provide instant help, some cryptic ones require a little extra thinking.