Playing to safe?

Here's a game I just drew today by argeement. I had offered a draw earlier but when my opponent declined, I thought he had something up his slevee; then he offered a draw several moves later. Can one of you give a fresh look at this game and tell me if I should have played differently somewhere in the later part of the game?

8. Bb3. Your light squared bishop is your "good bishop" because your central pawns are on dark squares. This is an important piece to keep. Since 8. Bb3 allows black to trade a knight for it, I prefer 8. Bd3.

12. Ra5. Rooks work much better from behind than from the side. I don't see any future for the rook here. 

17. Na4. Your knight doesn't really have anywhere to go from a4. It's really lucky that your opponent plays a6 to let your knight go to b6. Even on b6, though it's far into your opponent's camp, it never proves useful.

You should be looking for ways to open the position. Maybe 17. Nce2 followed by c4. 

20. c3. I think 20. c4 to open the position is better. 

23. cxd4. I prefer Qxd4 and c4. Notice how once the pawns all get locked you couldn't find a way to make progress.  You want to open the position by making pawn exchanges. 

Did you play it too safe? In the final position you dominate the queenside and have possible pawn breaks--your opponent does not. You should have taken your time to build up a winning assault, then attacked without much risk.

Eg, 42.Rc1 Qe8 43.Rca1 Qc6 44.Qa3 Qe8 - Now you must see Black's problem.  Your queenside space advantage allows you to triple up your major pieces, while your opponent can't do much at all. Now it's time to attack.

45.Na4! 45.Bxa4 46.Qxa4 Qxa4 47.R1xa4 Kd7 and again the position is quiet and closed and you have time to prepare for your final breakthrough.

48.b3 Ra8 49.Ra2 Rcc8 50.Kd3 Rab8 and it's time again. 51.b5! axb5 52.Rxb5 and White's a pawn up with clear queenside superiority--an easy win.

 8. Bb3 & 12. Ra5: So I need to keep the opposite color bishop of my pawns, got it. I had planned for my opponet to take that bishop and then I'd have the open file for my rook to support my knight in the middle. 

17. Na4 : I would have played Nb6 regardless of wether he pushed a6 or not.Doesn't that win the rook on a8?

 20. c4 : I wanted to protect the pawn on b4, if I don't then 20. ... Nxb4 21. Qb3 Bxc5.

 23. cxd4 : I had wanted the extra support for my e pawn in case he played g5 and then f4, but you're right, that was probably my last chance to open things up and I would have had enough time to protect it anyway.

Thanks, Loomis! 

"I had thought about tripling up my pieces on the a-file"

You discarded a winning plan because...

"I didn't want to move my knight because the would have freed up his other rook, there wasn't any assurance that line would have occured."

Free his rook to go where? Black has no counterplay in the center or kingside because the pawns are completely locked, and Black doesn't have enough space on the queenside to organize an effective defense.

You should assume your opponent will play his best move. After 45.Na4, do you see any defense for Black that holds? If he doesn't play 45...Bxa4 then 46.Nc3 and either 47.Nxb5 or 47.b5 again lead to a winning breakthrough.