user2429:        [FEN "8/5p1k/1P4p1/2P4p/2b4P/5Q2/5PP1/4qBK1 b - - 0 44"]

This position occurred on move 44 in the Carlsen vs Gelfand game in the World Championship Candidates, 2013. 
Here, Gelfand played the losing move 44...Qxf1+. However, I analyzed the position after 44...Bxf1! and I do not see a win for White. Black sets up a blockade to stop the queenside passed pawns from advancing. 
       [FEN "8/1Q3p1k/1P4p1/2P4p/2b4P/8/5PP1/4qBK1 w - - 0 44"]



        1. Qf3 Bxf1 
        2. Qxf7+ Kh8 
        3. Qf6+ Kh7 
        4. Kh2 Qe8 
        5. Qf4 Qd7
        6. Qf3 Bb5 
        7. b7 Qc7+  
        8. g3 Kg7 

And how does White win? Black blockades the passed pawns. If White tries to use his kingside pawn majority, his own king gets exposed and could lead to a perpetual check. 

user2429: One winning line involves an exchange of queens and bringing the king to e5. 
      [FEN "8/5p1k/1P4p1/2P4p/7P/5Q2/5PP1/4qbK1 w - - 0 1"]

1. Qxf7+ Kh8 2. Qf6+ Kh7 3. Qf4 Bb5+ (3... Bc4+ 4. Kh2 Bd5 5. c6 Bxc6 6. Qc7+
Kh6 7. Qxc6 Qxf2 8. Qc1+ Kh7 9. Qc7+ Kh6 10. Qd8 Qf4+ 11. Kg1 Qc1+ 12. Kf2 Qf4+
13. Ke2 Qe4+ 14. Kd1 Qb1+ 15. Kd2 Qb2+ 16. Kd3 Qb3+ 17. Ke4 Qc2+ 18. Ke5 Qc5+
19. Ke6 Qc6+ 20. Ke7 Qe4+ 21. Kd6 Qf4+ 22. Kd7 Qd4+ 23. Kc7 Qf4+ 24. Kc8 Qg4+
25. Kb8 Qf4+ 26. Qc7 Qf8+ 27. Kb7 Qf1 28. Ka7 Qa1+ 29. Kb8 Qh8+ 30. Kb7 Qf8 31.
Kc6 Qf6+ 32. Kd5 Qf5+ 33. Qe5 Qd7+ (33... Qd3+ 34. Kc5 Qa3+ 35. Kc6 Qa4+ 36.
Kb7 Qd7+ 37. Kb8 Qd8+ 38. Ka7 Qxh4 39. Qh8+ Kg5 40. Qd8+ Kg4 41. Qxh4+) 34. Kc5
Qc8+ 35. Kd4 Qa8 36. Ke3 Qa3+ 37. Kf2 Qa8 38. Qg5+ Kg7 39. Qe7+ Kh8 40. b7 Qb8
41. Kf3 Kg8 42. Qe6+ Kg7 43. Qc8) 4. Kh2 Qe7 5. Kg3 Kg7 (5... Bc6 6. Qc7 Qxc7+
7. bxc7 Bb7 8. Kf4 Kg7 9. Ke5 $1 $18) (5... Kg8 6. c6 Bxc6 7. Qc4+ Kg7 8. Qxc6
Qe5+ 9. Kh3 Qf5+ 10. Kh2 Qxf2 11. Qc3+ Kh7 12. Qb4 Qe3 13. b7 Qe5+ 14. Kg1 Qe3+
15. Kf1 Qd3+ 16. Kf2 Qc2+ 17. Kf3 Qc6+ 18. Kg3 Qc7+ 19. Kh3 Qd7+ 20. Kh2 Qc7+
21. g3 Qc2+ 22. Kg1 Qc1+ 23. Kf2 Qc2+ 24. Ke3 Qc1+ 25. Kd4 Qg1+ 26. Kd5 Qg2+
27. Kd6 Qxg3+ 28. Ke6 Qe3+ 29. Kf7 Qf3+ 30. Ke7 Qe2+ 31. Kd8 Qd3+ 32. Ke8 Qe3+
33. Qe7+ $18) 6. Qd4+ (6. Qc7 $2 Qxc7+ 7. bxc7 Ba6 8. Kf4 Kf6 $1 9. f3 Bc8 10.
g4 Bb7 $11) 6... Kh7 (6... Kf7 7. Qd5+ Kg7 8. c6 $18) 7. Qd6 Qg7 (7... Qb7 8.
Qc7+ Qxc7+ 9. bxc7 Ba6 10. Kf4 Kg7 11. Ke5 $1 $18) 8. Qc7 Qxc7+ 9. bxc7 Ba6 10.
Kf4 Kg7 11. Ke5 (11. Kg5 $2 Bc8 12. f3 Be6 13. g4 hxg4 14. fxg4 Bc8 15. h5 Bd7
$1 16. c6 (16. hxg6 Bc8 17. Kf4 Kxg6 18. g5 Kh5 19. Ke5 Kxg5 20. Kd6 Kf6 21.
Kc6 Ke5 22. Kb6 Kd5 23. Ka7 Kxc5 24. Kb8 Bf5 25. c8=Q+ Bxc8 26. Kxc8 $11) 16...
Bc8 $11) 11... Bc8 12. Kd6 Kf6 13. Kc6 Ke7 14. Kb6 Kd7 15. f3 Ke7 16. Ka7 Kd7
17. Kb8 Ba6 18. g3 Ke7 19. c8=Q Bxc8 20. Kxc8 1-0

Engine output after 3. Qf4! 
+-  (3.61): 3...Bb5+ 4.Kh2 Qe7 5.Kg3 Bc6 6.Qc7 Qxc7+ 7.bxc7 Bb7 8.Kf4 Kg8 9.Ke5 Kf7 10.Kd6 Bc8 11.Kc6 Ke6 12.Kb6 Kd7 13.f3 Ke7 14.Ka7 Kd7 15.Kb8 Ba6 16.g3 Kc6 17.c8Q+ Bxc8 18.Kxc8 Kxc5 19.Kd8 Kd5 20.Ke8 Ke6 21.f4 Kf6 22.Kf8 Kf5 23.Kg7 Kg4 24.Kxg6 Kxg3 25.Kxh5 Kf3 26.Kg6 Kg3 27.h5 Stockfish Depth 26. 

2429: <pre><code>       [FEN "8/5p1k/1P4p1/2P4p/2b4P/5Q2/5PP1/4qBK1 b - - 0 44"]
</code></pre>

<p>This position occurred on move 44 in the <a href="http://www.chessgames.com/perl/chessgame?gid=1713491&amp;kpage=24">Carlsen vs Gelfand</a> game in the World Championship Candidates, 2013. </p>

<p>Here, Gelfand played the losing move 44...Qxf1+. However, I analyzed the position after 44...Bxf1! and I do not see a win for White. Black sets up a blockade to stop the queenside passed pawns from advancing. </p>

<pre><code>       [FEN "8/1Q3p1k/1P4p1/2P4p/2b4P/8/5PP1/4qBK1 w - - 0 44"]



        1. Qf3 Bxf1 
        2. Qxf7+ Kh8 
        3. Qf6+ Kh7 
        4. Kh2 Qe8 
        5. Qf4 Qd7
        6. Qf3 Bb5 
        7. b7 Qc7+  
        8. g3 Kg7 
</code></pre>

<p>And how does White win? Black blockades the passed pawns. If White tries to use his kingside pawn majority, his own king gets exposed and could lead to a perpetual check. </p>
 2429: <p>One winning line involves an exchange of queens and bringing the king to e5. </p>

<pre><code>      [FEN "8/5p1k/1P4p1/2P4p/7P/5Q2/5PP1/4qbK1 w - - 0 1"]

1. Qxf7+ Kh8 2. Qf6+ Kh7 3. Qf4 Bb5+ (3... Bc4+ 4. Kh2 Bd5 5. c6 Bxc6 6. Qc7+
Kh6 7. Qxc6 Qxf2 8. Qc1+ Kh7 9. Qc7+ Kh6 10. Qd8 Qf4+ 11. Kg1 Qc1+ 12. Kf2 Qf4+
13. Ke2 Qe4+ 14. Kd1 Qb1+ 15. Kd2 Qb2+ 16. Kd3 Qb3+ 17. Ke4 Qc2+ 18. Ke5 Qc5+
19. Ke6 Qc6+ 20. Ke7 Qe4+ 21. Kd6 Qf4+ 22. Kd7 Qd4+ 23. Kc7 Qf4+ 24. Kc8 Qg4+
25. Kb8 Qf4+ 26. Qc7 Qf8+ 27. Kb7 Qf1 28. Ka7 Qa1+ 29. Kb8 Qh8+ 30. Kb7 Qf8 31.
Kc6 Qf6+ 32. Kd5 Qf5+ 33. Qe5 Qd7+ (33... Qd3+ 34. Kc5 Qa3+ 35. Kc6 Qa4+ 36.
Kb7 Qd7+ 37. Kb8 Qd8+ 38. Ka7 Qxh4 39. Qh8+ Kg5 40. Qd8+ Kg4 41. Qxh4+) 34. Kc5
Qc8+ 35. Kd4 Qa8 36. Ke3 Qa3+ 37. Kf2 Qa8 38. Qg5+ Kg7 39. Qe7+ Kh8 40. b7 Qb8
41. Kf3 Kg8 42. Qe6+ Kg7 43. Qc8) 4. Kh2 Qe7 5. Kg3 Kg7 (5... Bc6 6. Qc7 Qxc7+
7. bxc7 Bb7 8. Kf4 Kg7 9. Ke5 $1 $18) (5... Kg8 6. c6 Bxc6 7. Qc4+ Kg7 8. Qxc6
Qe5+ 9. Kh3 Qf5+ 10. Kh2 Qxf2 11. Qc3+ Kh7 12. Qb4 Qe3 13. b7 Qe5+ 14. Kg1 Qe3+
15. Kf1 Qd3+ 16. Kf2 Qc2+ 17. Kf3 Qc6+ 18. Kg3 Qc7+ 19. Kh3 Qd7+ 20. Kh2 Qc7+
21. g3 Qc2+ 22. Kg1 Qc1+ 23. Kf2 Qc2+ 24. Ke3 Qc1+ 25. Kd4 Qg1+ 26. Kd5 Qg2+
27. Kd6 Qxg3+ 28. Ke6 Qe3+ 29. Kf7 Qf3+ 30. Ke7 Qe2+ 31. Kd8 Qd3+ 32. Ke8 Qe3+
33. Qe7+ $18) 6. Qd4+ (6. Qc7 $2 Qxc7+ 7. bxc7 Ba6 8. Kf4 Kf6 $1 9. f3 Bc8 10.
g4 Bb7 $11) 6... Kh7 (6... Kf7 7. Qd5+ Kg7 8. c6 $18) 7. Qd6 Qg7 (7... Qb7 8.
Qc7+ Qxc7+ 9. bxc7 Ba6 10. Kf4 Kg7 11. Ke5 $1 $18) 8. Qc7 Qxc7+ 9. bxc7 Ba6 10.
Kf4 Kg7 11. Ke5 (11. Kg5 $2 Bc8 12. f3 Be6 13. g4 hxg4 14. fxg4 Bc8 15. h5 Bd7
$1 16. c6 (16. hxg6 Bc8 17. Kf4 Kxg6 18. g5 Kh5 19. Ke5 Kxg5 20. Kd6 Kf6 21.
Kc6 Ke5 22. Kb6 Kd5 23. Ka7 Kxc5 24. Kb8 Bf5 25. c8=Q+ Bxc8 26. Kxc8 $11) 16...
Bc8 $11) 11... Bc8 12. Kd6 Kf6 13. Kc6 Ke7 14. Kb6 Kd7 15. f3 Ke7 16. Ka7 Kd7
17. Kb8 Ba6 18. g3 Ke7 19. c8=Q Bxc8 20. Kxc8 1-0
</code></pre>

<p>Engine output after 3. Qf4! </p>

<p><code>+-  (3.61): 3...Bb5+ 4.Kh2 Qe7 5.Kg3 Bc6 6.Qc7 Qxc7+ 7.bxc7 Bb7 8.Kf4 Kg8 9.Ke5 Kf7 10.Kd6 Bc8 11.Kc6 Ke6 12.Kb6 Kd7 13.f3 Ke7 14.Ka7 Kd7 15.Kb8 Ba6 16.g3 Kc6 17.c8Q+ Bxc8 18.Kxc8 Kxc5 19.Kd8 Kd5 20.Ke8 Ke6 21.f4 Kf6 22.Kf8 Kf5 23.Kg7 Kg4 24.Kxg6 Kxg3 25.Kxh5 Kf3 26.Kg6 Kg3 27.h5</code>  <code>Stockfish Depth 26.</code> </p>
