SeanWinshand vs ShaakSiv: game review

26…e5 is a mistake: Black's winning chances go from 43% to 24%.

• White answers 27.fxe5, which takes the pawn on e5.
• After fxe5, White wins 1 point of material within 2 moves.
• Better was 26…g6 (+0.76): makes an escape square for the king, so back-rank checks lose their sting.

Better: 26…g6 makes luft for the king and takes h5 away from the queen. Engine line: 27.Re5 Qf8 28.Rbe1 Bc6 29.Qg4 Qg7 (+0.76).

28.Rh5 is a blunder: White's winning chances go from 70% to 13%.

• Black answers 28…Qg6+: the queen forks the king and the rook: both can't be saved at once.
• After Qg6+, Black wins 5 points of material within 4 moves.
• Better was 28.Rbe1 (+2.25): the rook takes the open e-file.

Better: 28.Rbe1 stops …Qg6+. After 28…Re8 29.Qg5 Qf8 30.R1e3 Rxe5 31.fxe5 Qd8, the rooks are traded (+2.25).

28…Qg6+! The only good move here: every alternative is clearly worse.

• The queen forks the king and the rook: both can't be saved at once.
• The queen joins the attack: it now hits 2 squares around the White king.
• The next best move, 28…f5, would drop Black's winning chances from 87% to 7% (+6.84).
• 28…Qg6+ wins a rook, picking it up with 29…Qxb1+.
• Sets up a sequence and wins a rook once the captures settle, picking it up with 29…Qxb1+.
• White answers 29.Kf1.

32…Bxf5!! A real sacrifice: Black gives up material and the engine still rates it best.

• Puts the bishop on f5 where it can be taken.
• White can take, but after 33.Nxf5 Rd1+ 34.Ke2 Re8+ the engine rates it −5.01.
• Takes the pawn on f5.
• Protects the queen on g6, which was hanging.
• 32…Bxf5 stops the mate threat fxg6.
• White was threatening fxg6, with mate in 5. Bxf5 takes care of it.

• The idea: 32…Bxf5!! offers the bishop on f5. Taking it gives Black an attack worth more than the bishop.
• What Black gives up: 32…Bxf5 puts the bishop on f5 where it can be taken by the knight on d4 and the rook on h5. That's a bishop on offer.
• If White takes the bishop: 33.Nxf5 is met by 33…Rd1+. Then 34…Re8+ gives check, and 35…Rd3+ gives check. Black is still two pawns down, but the attack is worth more: Black is winning (−4.52). This is White's best try.
• Without the sacrifice: The best move without the sacrifice, 32…Qxh5, is clearly weaker (+0.53 against −5.01). White answers 33.Qxh5, taking the queen on h5. That would leave Black a little worse.

34…Re8+!! A real sacrifice: Black gives up material and the engine still rates it best.

• Leaves the rook on d1 where it can be taken.
• Taking is too dangerous: White's best reply is 35.Kf3 Rd3+ 36.Ne3 b5 instead (the engine rates it −4.51).
• The rook takes the open e-file, aiming at the king.
• The rook joins the attack: it now hits 2 squares around the White king.
• 34…Re8+ takes the open e-file, aiming at the king, and joins the attack on the king.
• Gives check, so the reply is forced.

• The idea: 34…Re8+!! leaves the rook on d1 hanging. Taking it leads to mate.
• What Black gives up: The rook on d1 is attacked by the king, and 34…Re8+ doesn't save it. That's a whole rook on offer.
• If White takes the rook: 35.Kxd1 is met by 35…Qg1+. Then 36…Qe1+ gives check, and 37…Re2# is mate.
• White's best try: White's best is to leave the rook alone and play 35.Kf3. Black answers 35…Rd3+. Then 37…Kf7 threatens …Qf5+, winning a knight, and 38…Kxe8 takes the rook on e8. Material is level and Black is winning (−4.51).
• Why not save the rook first?: Saving it with 34…Rd7, the best way to do that, is clearly weaker (0.00 against −4.51). White answers 35.Rh8+. That would leave Black level.

35.Kxd1 is a mistake: White's winning chances go from 16% to 0%. It allows mate in 3.

• Black answers 35…Qg1+: the queen joins the attack: it now hits 2 squares around the White king.
• Better was 35.Kf3 (−4.51): the king steps out of check to f3.

Better: 35.Kf3 threatens Rh8+, with mate in 5. After 35…Rd3+ 36.Ne3 b5 37.Rh8+ Kf7 38.Rxe8 Kxe8 39.Qh8+, the rooks are traded (−4.51).

• Both sides followed opening theory up to 11…Bd7: 22 moves in all, 11 by White and 11 by Black.
• Theory runs out after 11…Bd7: too few games between strong players reached this position to go further.