Not every game is because of a single decisive mistake. Going into an ending two pawns down is usually enough to lose. Not sure if this would've been a draw or loss with best play, but here's a free endgame tablebase I found that should give you some insight:
http://www.shredderchess.com/online-chess/online-databases/endgame-database.html
I'm not good enough, but it seems to me that all your problems came from your weak queenside pawns. Perhaps what I'm going to say makes no sense, but looking at your game I like the idea of 10... c4.
Well defended although it was bad chess etiquette to offer the draw - in such positions (even in totally drawn ones) it's up to the player with the material advantage to extend the offer.
That said, it did seem to pay off as the final position is probably winning for him.
Really? Hmmm....
Chess is too gentleman-ish.
I agree with tliu -- if you want to offer a draw, offer a draw. Etiquette shouldn't bear on that decision. If he doesn't want to accept your draw offer, then he doesn't have to.
You can, there's no law against it - but you (and I don't mean anyone specifically!) just make yourself look like an idiot when you offer a draw in a position which your opponent can never realistically lose anyway and you're the one defending. Any half-decent player understands this.
If the h-pawns are traded you could probably win. So 37.Rf2 maybe. If 37...h4 then 38.Kf2 looks like you can win by going for mate with your passed f-pawn.
Idunno about 38.g4 Ra3 39.h3 Ra4. If 40.Rg8+ then I go Kf4 threatening Ra2+.
If 40.Rf8 I spam checks and if your king gets too far away from the pawns and I might have tricks with Ra3. One idea I had was 40.Rf8 Ra2+ 41.Ke3 Ra3+ 42.Kd4 Ra4+ 43.Kc3 Ra3+ 44.Kb4 Re3 45.Kc4 Ra3 46.Kd4 Ra4+.
You can, there's no law against it - but you (and I don't mean anyone specifically!) just make yourself look like an idiot when you offer a draw in a position which your opponent can never realistically lose anyway and you're the one defending. Any half-decent player understands this.
In your first post you said it's bad etiquette to offer a draw in a dead drawn position. I can't say that really makes any sense to me at all. To me bad etiquette would be offering a draw, having the opponent decline, and then continuing to offer a draw every move for the next 20 moves.
That's obviously just rude - you're right. It's not necessarily bad etiquette to offer a draw in a dead drawn position ...in the example here, the OP was completely busted when the draw was proposed.
But for example if you have a totally drawn K and P vs K ending (and you only have the K) then it's always bad etiquette to offer the draw no matter how drawn it is.
Someone that doesn't understand that is either very weak, or has played very little OTB chess, or both.
Thanks for the comments everybody.
paulgottlieb, 29...Rc6! So simple! Whoops.
JamesColeman, thanks for the pointer. I don't completely agree, but it would have been easy for me to hold off for five or so moves to see if he could make progress.
I definitely agree that repeated draw offers are very rude.
In this game I felt cramped the entire time and got into an ending down two pawns. But I don't see where I made a truly decisive error. Any thoughts?
Thanks in advance.