I just found out that my game ended differently than I thought. I thought that Swiss_dragon played 22... Nxb3 and after the 23.cxb3 Rc2, seems I didn't read my email very well    
But it doesn't matter, the game ended anyway at move 23 with the evaluation of Houdini. 
The difference in evaluation I found between Rybka and Houdini was however in the variation with 22 ... Nxb3. Even then I think it is pretty good playable for black.

I think that 15.Na3 is also interesting: I mean 14.Ndxb5 Qb6 15.Na3 Black will probably go slowly with moves like Be6, Rfc8, Rb8 but I think white can cause problems with Rhe1, f4, e5.
The knight on a3 is passive for the time being, but it cannot be chased away by the not-longer-existing b-pawn and it covers c2.

Very entertaining stuff! Looking at the games without an engine running at the background my favourite White's aproach is MamboVipi's 15.Nxd6! Maybe you are right that the objective evaluation is not a White's advantage but OTB i believe that Black will face some hard time. Are there any reasonable alternatives for Black on the 14nth move according to your analysis? (instead of 14...Qb5)

I am surprized to see only one corr game in my database after this ...b5 gambit:

[Event "DDR"]
[Site "corr"]
[Date "1988.??.??"]
[Round "?"]
[White "Mittag"]
[Black "Reichel"]
[Result "1-0"]
[ECO "B78"]
[PlyCount "46"]
[EventDate "1988.??.??"]
[Source "Chess Mail Ltd"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be3 Bg7 7. f3 O-O 8. Qd2 Nc6 9. Bc4 Bd7 10. Bb3 Rc8 11. h4 h5 12. O-O-O Ne5 13. Bg5 b5 14. Ndxb5 Qa5 15.Na3 Be6 16. Nd5 Qd8 17. Kb1 Nxd5 18. exd5 Bf5 19. Rhe1 Re8 20. Ka1 Qb6 21. Be3 Qb7 22. Qa5 Bxc2 23. Nxc2 Rxc2 1-0

Bring it on Swiss Dragon! I would very much like to play with you a game in this line but i have very very much work to do right now (for other things and of course for my Tarrasch book for QC  ) so my spare time is very limited or simply not existant. Browsing at interesting post on chesspub is really a luxury for me! But i'll keep an eye on this because i'm waiting to see some hardcore Dragon analysis!

MNb wrote on 01/26/11 at 22:23:18:


Well, one challenge game is still running. It probably wouldn't be too clever to make anything public before it is over. But if my opponent keeps taking weeks of time to play one move, we may need to abort it for the sake of the curiousity of other readers. If you have specific questions, you can email me and I can give you some advice.

Another game has ended, MamboVipi-Swiss_Dragon and ended in a draw (with Houdini evaluation close to 0.00). MamboVipi found a pretty interesting approach to play it safely and I had to find a couple of accurate moves to equalize. 

So then 0.5:3.5 in Black's favour and my (so far perfect) performance is ruined.

The third game is also finished.

Pending Houdini analysis, I think that Black's Position is preferable.

White play can be improved, but b5 is a very interesting alternative.

I suppose that some analysis will be published when the challenge has ended.

I've taken up the challenge as well.

Just sended my first movement on the Challenge to your personal e-mail.