The key of this three-mover is not too difficult to spot given the
presence of a strong defence, however the play is excellent and an
example of a “continued theme”.
After the key 1.Sg2, threatening 2.Sxc6+ Ke4 3.Rxd4, any move of the bishop or rook will defend. 1...B random is met by 2.Bxc3+ Bd4 3.Re1 or 2..Ke4 3.Qb1, but 1...Bb6 is a correction, closing the queen’s path to b1, but also preventing the rook from moving on the rank. After the continuation 2.Bf3 (threat 3.Sxc6) any move of the rook defeats, giving the variations 2...R random 3.Bxd6 and 2...Rc5 3.Bxc3. Hence correction play is shown on both Black’s first and second moves. A similar thematic repetition is shown after the rook’s defences: 1...R random 2.Re1+ Be3 3.Bxc3; 1...Rxc4 2.Qf3 (threat 3.Qxf4) B random 3.Bxd6; 2...Bc5 3.Sc6. Note how 2.Qf3 only works after the correction defence, keeping the play accurate. The correction play shows a Grimshaw following critical moves. The remaining variation is 1...Ke4 2.Bxd6 threat 3.Qxc6. A masterpiece.