It's one of those times when your position looks like it came out of an endgame manual. Which pawn to push? I chose the wrong plan which begins with 37...Ra1. The white king was able to menace tha passed A pawn and rook, and ultimately the A pawn was captured. The right plan would have started with 37... Rg4, seeking an exchange of rooks. White will, of course, refuse to exchange the rooks and play something like 38. Ra6. At this point, black should move his king and passed H pawn down the file while his rook screens them from any attack. The passed A pawn will serve only as a diversionary tactic.