http://chesstempo.com/chess-problems/43381This is in response to a comment by petrovski. Maybe it's better to post lengthy variations here rather than clutter up the comments bar? Hope this helps someone.
(1.f7 Ke6) 2. f8=Q? Rxf8 3.Rg8 Rf1+ 4. Kc2 Rf2+ = (Crafty 22.0).
Although the lower half of the board looks wide open, black has tricks with square-control that pick up both the g and the h pawn in return for the rook:
1) 5. Kc1 Rf1+ repeating
2) 5. Kd1 Rh2 6. h8=Q Nf2+ 7. Ke2 Rxh8 8. Rxh8 Nxg4 9. Ra8 Nf6 10. Rxa7 Nd5 11. Rb7 Nxb4 12. Rxb6+ Nc6 = (endgame tablebase)
3) 5. Kd3 Rh2
a) 6. Kxe4 Rxh7 = (says computer at depth 20 from here)
b) 6. h8=Q Nf2+ 7. Kd4 Rxh8 8. Rxh8 Nxg4 =, e.g. 9. b5 Kd6 10. Rf8 Ke6 11. Ra8 Nh6 12. Rxa7 Nf5+ 13. Kc3 d5 and it's white who's defending.
4) 5. Kb3 Rf3+
a) 6. Ka4 Nc3+ 7. Kb3 Ne4+ repeating
b) 6. Kc4 Nd6+ 7. Kd4 Nf7 8. g5 Rh3 9. g6 Ne5 10. h8=Q Rxh8 11. Rxh8 Nxg6 =, e.g. 12. Rh6 Kf7 13. Rh2 Ne7 14. b5 Ke8 15. Rh8+ Kf7 16. Ra8 Ke6 17. Rxa7 Nf5+ 18. Kc3 d5 and white is pressured again.
