1. g6 seems intuitive, but there are some complicated lines.
After 1. g6 fxg6? 2. f6 wins the pawn race.
After 1. g6 hxg6 2. hxg6 fxg6 3. f6 also wins. However 2... exf5+ transposes the line below...
So after 1... exf5+ White has to be careful.
2. Kxf5 hxg6+ 3. hxg6 fxg6+ 4. Kxg6 is a tied pawn race. So are 2. Kf4, 2. Kf3, and 2. Ke3.
2. Kd4 is losing because Black can queen with a check. 1... hxg6 2. hxg6 fxg6 3. e6 a3 4. e7 a2 5. e8=Q a1=Q+ 6. Kd5 (6. Kd3? Qd1+ and Qe1+) 6... Qd1+! 7. Ke6 Qe2+ or 7. Kc6 Qa4+!
That leaves 2. Kd3, which is interesting because White threatens to stop the A-pawn with Kc2. If 2... hxg6 3. hxg6 fxg6 4. e6 and now if 4... a3 5. Kc2 wins, or 4... Kb3 5. e7 and White queens first. 5... a3 6. e8=Q a2 7. Qb5+ Ka3 which looks a bit tricky, but White just plays 8. Kc2 a1=N+ (8... a1=Q 9. Qb3#) 9. Kc3 with forced mate.
This is master level.
ReplyDeleteSolution...
1. g6 seems intuitive, but there are some complicated lines.
After 1. g6 fxg6? 2. f6 wins the pawn race.
After 1. g6 hxg6 2. hxg6 fxg6 3. f6 also wins.
However 2... exf5+ transposes the line below...
So after 1... exf5+ White has to be careful.
2. Kxf5 hxg6+ 3. hxg6 fxg6+ 4. Kxg6 is a tied pawn race. So are 2. Kf4, 2. Kf3, and 2. Ke3.
2. Kd4 is losing because Black can queen with a check. 1... hxg6 2. hxg6 fxg6 3. e6 a3 4. e7 a2 5. e8=Q a1=Q+ 6. Kd5 (6. Kd3? Qd1+ and Qe1+) 6... Qd1+! 7. Ke6 Qe2+ or 7. Kc6 Qa4+!
That leaves 2. Kd3, which is interesting because White threatens to stop the A-pawn with Kc2. If 2... hxg6 3. hxg6 fxg6 4. e6 and now if 4... a3 5. Kc2 wins, or 4... Kb3 5. e7 and White queens first. 5... a3 6. e8=Q a2 7. Qb5+ Ka3 which looks a bit tricky, but White just plays 8. Kc2 a1=N+ (8... a1=Q 9. Qb3#) 9. Kc3 with forced mate.