# In Crazyhouse, what is the minimum number of moves to achieve maximum material difference?

If one side captures everything and promotes all pawns (including the opponent's re-placed pawns) to a queen, it is possible to achieve 206 points of material difference 18 queens, 4 rooks/knights/4 bishops).

Here is an example solution.

``````[FEN "8/4k3/8/8/RNBQ1BNR/RNBQKBNR/QQQQQQQQ/QQQQQQQQ b - - 36 137"]
``````

What is the theoretical minimum amount of moves for achieving this material difference, and how would one implement it?

This solution finishes with White's 54th move. Every White move other than the early e-pawn moves is one of the following:

1. A promotion

2. A pawn capture by a Queen moving from the eighth rank

3. Placing a piece

4. Placing a pawn on the seventh rank

``````[FEN ""]

[Variant "Crazyhouse"]

1. e4 d5 2. exd5 c6 3. dxc6 a5 4. p@c7 Ra6 5. cxb7 Rb6 6. p@a7 Rxb2 7. axb8=Q Rxa2 8. bxc8=Q Rxc2 9. p@a7 p@b2 10. Qxb2 Rxd2 11. a8=Q e5 12. Qxa5 Rxf2 13. p@b7 Ke7 14. b8=Q p@b3 15. Q8xb3 Kf6 16. p@b7 Rxg2 17. b8=Q p@b5 18. Q8xb5 Rxh2 19. p@a7 p@a6 20. a8=Q Rd2 21. Qa8xa6+ Kg5 22. N@c3 Kf4 23. p@e7 Kg3 24. exf8=Q f6 25. p@f7 g6 26. fxg8=Q p@a7 27. N@g5 p@a3 28. Qfxa3 p@c5 29. B@h3 Rd7 30. cxd8=Q Re7 31. p@g7 Re8 32. gxh8=Q Rf8 33. Qhxh7 Re8 34. B@h6 Re7 35. p@f7 Rb7 36. f8=Q e4 37. Qfxf6 e3 38. Qgxg6 e2 39. p@e7 Rb8 40. e8=Q Rb6 41. p@b7 Rc6 42. b8=Q+ Rd6 43. Qbxa7 Rd7 44. Qcxc5 Rf7 45. Qexe2 Rf8 46. p@g7 Kh4 47. gxf8=Q Kg3 48. p@g7 Kh4 49. g8=Q Kg3 50. p@e7 Kh4 51. e8=Q Kg3 52. R@h8 Kh4 53. R@f7 Kg3 54. Q@g7
``````

Reference solution in 58 moves by /u/CratylusG on reddit.com - missing last three placements: https://lichess.org/fP8zuniL

``````[fen ""]

1. a4 b5 2. axb5 a6 3. bxa6 Bb7 4. axb7 Ra2 5. e4 f5 6. exf5 g6 7. fxg6 Rxb2 8. gxh7 Rxc2 9. hxg8=Q Rxd2 10. P@g7 Rxf2 11. gxh8=Q P@b2 12. Qxb2 Rxg2 13. P@h7 c5 14. h8=Q P@c3 15. Qhxc3 c4 16. Qgxc4 Rxh2 17. P@h7 P@d4 18. h8=Q d5 19. Qhxd4 P@g3 20. P@a7 Bh6 21. axb8=Q Kf7 22. Qbxg3 Bf4 23. b8=Q Ke6 24. Qbxf4 Qb8 25. N@f5 Kf7 26. P@c7 Rh8 27. cxb8=Q e5 28. Qbxe5 Rb8 29. P@c7 P@b3 30. cxb8=Q P@d6 31. Q8xb3 Kf8 32. B@d8 Kf7 33. P@b7 Kf8 34. b8=Q Kf7 35. N@e7 Kf8 36. Qbxd6 Kf7 37. P@b7 Kf8 38. b8=Q Kf7 39. Q8b4 Kf8 40. P@b7 Kf7 41. b8=Q Kf8 42. Q8b5 Kf7 43. P@a7 Kf8 44. P@b7 Kf7 45. P@c7 Kf8 46. a8=Q Kf7 47. b8=Q Kf8 48. c8=Q Kf7 49. R@e6 Kf8 50. Qaxd5 Kf7 51. P@a7 Kf8 52. a8=Q Kf7 53. P@a7 Kf8 54. Qac6 Kf7 55. a8=Q *
``````