One of my online chess games. White had a significant advantage, squandered it, then misplayed a forced draw. Some annotations below . . .
3. Bb5 Ruy Lopez
3. Bxc6 Exchange Variation
5. …f6 Gligoric Variation
17. …c4? This opens up the b-file for White’s rook, although he ends up not using it.
20. a5? 20. Rb1 is better.
20. …Bxd3?? This looks like a losing move. I could have defused the king-side problems with 20. …b5.
21. Rxd3 21. axb6 was probably worth a try.
22. …b5 This is now a little late.
23. d4? White is still winning but 23. Rb1 Qd7 24. Nxb5! axb5 25. a6 was the way to go.
36. Rb6? At this point, White has pretty much defused his own attack. 36. Rd4, opening b6 for the queen, looks better.
37. e4? Don’t like it because White can survive 37. …Rxe4 38. Qf7+, and White is going to have back rank problems.
40. …Re5? Believe it or not, Black can draw with 40 …Qf5+!! 41. Kxe1 followed by an endless series of checks. The rook move actually gives White some chances.
49. Rf2 White should have no worse than a draw at this point.
64. g7?? Losing. White can draw with 64. h5 or 64. Kg7