Daniele Gatti (Italy)
1.c8Q+! White is in serious trouble, and he should quickly get rid of all his pieces in order to achieve stalemate. Unfortunately, if the first Queen sacrifice appears trivial, the a7 pawn seems to be not an easy deal.
1..Kd6 2.Qb8+ Kd7 3.Qc8+ Kd6 4.Qb8+ Ke7 Black is forced to change his plan or he will run into threefold repetition. Of course, he cannot take the white Queen, or the stalemate for White would be immediate after a8=Q+.
5.Qc7+ Ke6 6.Qe5+ Kd7 7.Qg7+! Re7 8.Qg4+ Kc7 9.Qxg3+!
Thematy Try: 9.a8N+? Kb8! 10.Qxg3+ Kxa8!–+ Underpromotion is untimely. Black quickly improves his position and wins, whereas White still has to capture the enemy pawns.
Thematy Try: 10.Qxf2? Kxa7! 11.Qxf3 Ne6–+ To obtain the draw, White should win both the f2 and f3 pawns in one move, so that Black wouldn’t have time to reorganize his army. That’s obviously impossible. As there is no way to capture them with check, the only chance to draw is to force Black to lose some tempos. This can be done only with the correct-timed underpromotion 10. a8=S+!. Black is now forced to lose 2 tempos in order to reach a8 and capture the Knight; this prevents him to improve his position.
10…Ka7 11.Qxf2! Kxa8 12.Qxf3! Ne6 13.Qf6! Re8 14.Qf7! Rh8+=
Right on time! Black King is in the corner of the board, no black pawns have been pushed, and black Rook and Knight are still uncoordinated, so white Queen can come into play. This will be enough for White to hold a positional draw.
Note: Every variation has been deeply tested with Stockfish 12 – 64 bit version, to ensure the soundness of the study.