Various proto-combinations spring to mind, based on Nxf7 and d5, then eating through the Black position with dxc6, cxb7 and bxa8=Q. It all looks very promising: 1. Nxf7 Kxf7 2. d5 and the pin on the c-file prevents cxd5; so Black's rook must go somewhere, when dxc6+ wins since any reply is met by cxb7. It does not matter if Black plays Qxc4, since bxa8 leaves White winning on material.
When you get down to details, however, it is not so easy. After 2. d5 Black plays Re4] attacking the white queen, when neither 3. dxc6+ Rxe4 nor 3. Rxb7+]? Kg8] works for White.
Mestel's move stemmed from these thoughts. By playing 1. e4] he repaired the fault. After 1 . . . fxe4 2. Nxf7 Kxf7 3. d5, the rook can no longer go to e4. White also threatens 2. exf5, or even 2. Nxf7 Kxf7 3. exf5. Summerscale played 1 . . . Rf6 when 2. Be7] Re6 3. Bh4] eliminated the Rf6 defence. The game ended 3 . . . fxe4 4. Nxf7 Kxf7 5. d5 b6 (If 5 . . . Rd6 6. dxc6+ Kf8 7. cxb7 Qxc4 8. bxa8=Q wins as usual) 6. dxe6+ Qxe6 7. Rbc1 a6 8. Rfd1 Ra7 9. Qxe6+ Kxe6 10. Bg3 Nd7 11. Rxc6+ Kf7 12. Bc7 Ke7 13. Rd4 resigns.
Yesterday's answer: 1 . . . Qf5+] 2. Kxf5 (2. Kd5 e4+ 3. Kc4 Qc5+ 4. Kb3 Qb4 mate) d5+ 3. Kg5 Be7+ 4. Kh5 g6 mate.Reuse content