Games: Chess

Just as grandmasters are always borrowing and refining each other's ideas, chess problems also see a continuous development of techniques. Take the "Bristol theme", for example. The first diagram is the problem by Frank Healey (a first-prize winner at the Bristol 1861 problem event) that gave the theme its name. It is White to play and mate in three.

The point of the first move of the solution becomes apparent only at the end: 1.Rh1!! Be8 (or Bd7 - other moves allow instant mate) 2.Qb1! Bb5 3.Qg1 mate! The rook had to clear the path from b1 to g1, enabling 2.Qb1 to be played at a moment when it defended the knight on b6.

The second diagram is a development that can best be described as an economical pair of Bristols. Composed by Francois le Lionnais in 1930, it is White to play and mate in three again and doubles up on Healey's original idea: 1.Nc2! and now 1...d3 2.Rh1 followed by 3.Qg1 mate, or 1...b5 2.Ra8 and 3.Qa7 mate.

Finally, another problem from 1930, this time a mate in six by Wilhelm Kramer. There's no white rook to perform the Bristol shunt, but White's king does the job in slow but sure Bristol fashion: 1.Ke1 cxd6 2.Kd1 d5 3.Kc1 d4 4.Kb1 d3 (or dxe3) 5.Ka1! d2 (or e2) 6.Qb1 mate!