Graham Banks wrote:Okay - a possible danger for you to consider before you decide on a4.
16.....a4; 17.Bd3, g6; 18.Bxg6+, hg; 19.Qxg6+, Bg7; 20.Bd4 followed by Rd3.
Interesting line...it looks like black MIGHT be able to defend with 20...Qe7 with the idea of 21 Rd3 e5 and if 22. Re1 Rf6. If its remotely possible I would rather defend this kind of thing than the pawn down endgame.
I have not got a vote yet, but my time to look at this is expiring so I will present what I looked at.
16...a4
17. b4 axb 18 axb Qc7 (I am not sure about 18...Ra5 as it helps the advance of the b pawn, but I would need to look at it more to be sure) is ok guess.
17. Bd3 g6 18. Qg4 Qc7. Maybe white goes for another trade with 19. Be4.
16...Qc7 17. Bb5 might be a bit annoying (17...Qxc2 18. Qxd7 does not look good) 17...BxB 18. QxB then what? maybe 18...d5 19 c3 a4 and white's queenside is a bit stymied I guess.
16...Rb8 might be interesting. If 17. Bd4 Be4 gets complicated....maybe in a good way for black. Of course white can play 17. b3 or 17. c3 but the queenside is looking a little less mobile.
No vote now...I will check in later to see other people's thoughts and vote for something.
-Sam