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  3. Cool study, mate!

White to move:

lichess.org/editor/k6b/P7/2N3K1/8/3p4/3P4/8/8 w - - 0 1

Thank you for the puzzle.
Solved against Stockfish level 6 in 80 move (Very hard for me).

[Event "Casual Standard game"]
[Site "lichess.org/V72ha0iZ"]
[Date "2019.04.13"]
[Round "-"]
[White "Just960"]
[Black "lichess AI level 6"]
[Result "1-0"]
[UTCDate "2019.04.13"]
[UTCTime "12:16:19"]
[WhiteElo "1500"]
[BlackElo "?"]
[Variant "From Position"]
[TimeControl "-"]
[ECO "?"]
[Opening "?"]
[Termination "Normal"]
[FEN "k6b/P7/2N3K1/8/3p4/3P4/8/8 w - - 0 1"]
[SetUp "1"]
[Annotator "lichess.org"]

1. Nb8 Kxa7 2. Nd7 Kb7 3. Kh7 Kc7 4. Nc5 Kb6 5. Ne6 Be5 6. Kg6 Kc6 7. Kf5 Kd6 8. Nf4 Bh8 9. Ke4 Bf6 10. Nd5 Be5 11. Nb4 Bf6 12. Nc2 Kc5 13. Ne1 Be7 14. Nf3 Kc6 15. Kxd4 Bb4 16. Kc4 Be7 17. d4 Bf8 18. d5+ Kb6 19. Ne5 Kc7 20. Nf7 Kd7 21. Kd4 Bd6 22. Ng5 Bf4 23. Ne6 Bd6 24. Ke4 Ke7 25. Nd4 Kd7 26. Nb5 Be7 27. Kf5 Bc5 28. Ke5 Bb4 29. Kd4 Be7 30. Kc4 Bh4 31. Kc5 Bg3 32. Nc3 Bd6+ 33. Kc4 Kd8 34. Ne4 Ke7 35. Kb5 Be5 36. Kc6 Kd8 37. Ng5 Ke7 38. Ne4 Kd8 39. Nd6 Bf6 40. Nc4 Ke7 41. d6+ Ke8 42. d7+ Kd8 43. Kd6 Bc3 44. Ke6 Bf6 45. Nd6 Bh4 46. Nb5 Bg5 47. Nc3 Bh6 48. Nd5 Bf8 49. Nf6 Bb4 50. Ne8 Bf8 51. Nf6 Ba3 52. Nd5 Bc5 53. Nc3 Be7 54. Ne4 Bh4 55. Nd6 Bf6 56. Nf7+ Kc7 57. Nd6 Kd8 58. Nb7+ Kc7 59. Nc5 Bh4 60. Na6+ Kd8 61. Nb8 Kc7 62. Na6+ Kd8 63. Nb4 Bf6 64. Nc6+ Kc7 65. Nb4 Bg5 66. Nd5+ Kb7 67. Kd6 Bh4 68. Ne7 Bg3+ 69. Ke6 Kc7 70. Nf5 Be5 71. Ke7 Bf6+ 72. Ke8 Kb7 73. Ne7 Bd4 74. d8=Q Bg7 75. Qc8+ Ka7 76. Nd5 Be5 77. Qd7+ Ka8 78. Kd8 Bh2 79. Kc8 Bf4 80. Qb7# { White wins by checkmate. } 1-0
Analyse de l'ordinateurTemps par coupFEN & PGN

The real solution is here.

[Event "Computer Chess Game"]
[Site "ff0-desktop"]
[Date "2019.04.13"]
[Round "-"]
[White "Stockfish 310318 64 POPCNT"]
[Black "Stockfish 310318 64 POPCNT"]
[Result "1-0"]
[TimeControl "40/120"]
[FEN "k6b/P7/2N3K1/8/3p4/3P4/8/8 w - - 0 1"]
[SetUp "1"]

{--------------
k . . . . . . b
P . . . . . . .
. . N . . . K .
. . . . . . . .
. . . p . . . .
. . . P . . . .
. . . . . . . .
. . . . . . . .
white to play
--------------}
1. Kf7 {+1,02/37} Kb7 {-99,54/35 1,9} 2. a8=Q+ {+56,01/33 0,7} Kxa8
{-99,90/43 1,9} 3. Kg6 {+0,08/34 1,8} Kb7 {-99,58/42 1,4} 4. Nd8+
{+0,00/36 1,8} Kb6 {-99,52/42 1,1} 5. Nf7 {+0,00/38 2,0} Kb5
{-99,54/42 1,2} 6. Nxh8 {+0,00/36 1,7} Kc6 {-99,54/43 0,8} 7. Kf6
{+99,53/38 1,3} Kd6 {-99,60/44 2,3} 8. Nf7+ {+99,53/36 0,7} Kd5
{-99,62/32 1,0} 9. Kf5 {+99,59/40 1,0} Kc6 {-99,68/45 2,0} 10. Ke5
{+99,61/41 0,7} Kd7 {-99,68/44 0,7} 11. Ng5 {+99,65/41 0,8} Ke7
{-99,70/44 0,8} 12. Ne6 {+99,69/45 1,4} Ke8 {-99,70/44 0,8} 13. Nxd4
{+99,69/42 0,7} Kd7 {-99,74/44 0,8} 14. Nf5 {+99,73/45 2,0} Kc6
{-99,76/44 0,8} 15. d4 {+99,77/42 0,6} Kd7 {-99,78/45 1,6} 16. d5
{+99,77/44 0,9} Ke8 {-99,80/50 1,5} 17. Ke6 {+99,81/46 1,1} Kd8
{-99,84/54 1,5} 18. d6 {+99,81/43 0,9} Ke8 {-99,84/56 0,8} 19. Ne7
{+99,85/55 1,0} Kd8 {-99,90/68 1,2} 20. Nc6+ {+99,83/44 1,1} Kc8
{-99,92/77 1,2} 21. d7+ {+99,85/49 1,1} Kc7 {-99,92/82 1,2} 22. d8=Q+
{+99,87/42 1,1} Kxc6 {-99,94/108 1,1} 23. Qa5 {+99,91/73 1,2} Kb7
{-99,94/1 0,1} 24. Kd6 {+99,95/92 1,3} Kb8 {-99,98/127 0,1} 25. Kc6
{+99,95/99 1,4} Kc8 {-99,98/1 0,1} 26. Qa8# {+99,99/127 0,1}
{White mates} 1-0

The idea is just winning one tempo. Kg6-f7-g6 and ...Ka8-b7-a8 win not tempo either.

@Sarg0n #1
Amazing Zugzwang! Thank you for publishing this study again!