Two tournaments were held last weekend: an over-the-board Open in Ennis, and the Ulster Masters in Q.U.B., with some games available from each. Twelve games from the Ennis event have been added to the archive here.
The round 4 game between Adam Collins and eventual winner Blair Connell produced a very interesting ending. In the first diagrammed position, it’s White to play, and he has a choice between the straightforward 46. Bd4 and the more radical 46. Bxh6 Kg6 47. Bxg5 Kxg5. There is some very interesting chess either way, and the reader is invited to think it through as an exercise. (Don’t read further if you want to try the exercise!)
46. ?
Adam Collins went for the second option, leading to the second diagrammed position. This is within the range of the Lomonosov tablebases, so we can reach definite conclusions, which is just as well, as there are many surprising points along the way.
This second diagrammed position is drawn with best play. White can draw via 48. a6, 48. Kd4 or the game’s 48. Kd5. After 48… Bxa5, though, the only move to draw is 49. Kc5!, keeping the bishop out of b6. In fairness, it is very hard to see why this is important, and the verdict rests on a single tempo in many variations. After 49… Bd8 50. Kb5(!) Kf6 51. h4 Ke6 52. g5 (or 52. h5) 52… Kd7 53. g6(!) Bf6 54. Kb6 Kc8 55. h5 Bg7 56. Kc5(!) Kc7 57. Kd5(!) b6 58. Ke6(!) and White draws, where (!) denotes an only move rather than necessarily a difficult one.
After the game’s continuation, Black played the precise 48… Bb6! (48… Bd2 and 48… Be1 are the only other moves that win), but after 49. Kb5 Bf2 50. Ka5, erred via 50… Kf6?; apart from waiting moves, the only way to win is 50… Kf4!, saving a vital tempo. After 51. h4 (only move), the position was again drawn with best play. After three further changes of fortune, it was White who made the final error, allowing Black to win.