I probably get this position at least once out of every 100 games, and probably more so.
Here is the problem I have with caring about my online rating; I lost this game in the opening, but won it back because my opponent didn’t know Lucenna, and didn’t play the endgame confidently. Okay, I hope he learned something from my valuable instruction time, but I probably didn’t get anything out of this game, and certainly got no fix for this lingering opening-hole, other than to suggest going back to the Ruy Lopez opening.
I meant to play 21. a4 instead of c4, simply moved too quickly. Either way, the game should be his but I’d say his level of play in this game went downhill once he started putting his pawns on the light squares (the bishop threats on that diagonal were now blocked by his pawns, and perhaps his king could have got over to the queenside with a rook to cover behind the king.