Through 10...Qf6, both players played the best moves. Then 11.Qe2 and 11.Qd1 are about equally good according to Stockfish 17.1 at low depth, but I got nowhere with 11.Qe2 in F Rhine vs S Valladares Caron, 2024. 11.Qd1 appears to be better. On Black's 12th move, Stockfish 17.1 at low depth says that 12...Qg6 is the only move. But around depth 35 it changes its "mind" and says that 12...h6! is significantly better. At depth 43/82, it assesses 12...h6! as giving White a +0.96 advantage, and 12...Qg6 as +1.25. My opponent held a draw with 12...h6! in F Rhine vs O Thau, 2024.

Chan played 12...Qg6?! instead, as almost everyone has. Another crossroads occurred at Black's 19th move. Black played 19...b6! in five games of mine (four as Black, one as White). See https://www.chessgames.com/perl/che... and O Thau vs F Rhine, 2024. Those four games were all drawn, although my opponent missed a win in M Ulenaers vs F Rhine, 2024. In the fifth game, I am Black against Johnny Owens. We have reached an ending with his queen and pawns (including one on a7) against my rook, two bishops, and pawns. I am worse, but should draw. Ulenaers played 21.Bg5+ against me, while everyone else played 21.Rh5.

In the present game, Chan played 19...Nxd3? At depth 45/89, Stockfish says that 19...Nxd3? is winning for White (+1.81). 19...b6! may be barely tenable for Black (+1.37), but it is quite possible that deeper analysis will show that it also loses. I have not yet looked deeply at Ulenaers-Rhine to see whether the line played in that game (21.Bg5+) is winning for White or if I could have improved.