Originally posted by tomtom232 The reason for ...0-0 and ...Bg6 is that after the line 9. Nd2 0-0 10. f3 Bg6 11. e4 Nh5 threatens Qh4+ so 12. g3 weakening the white structure somewhat and black is more flexible with a possible ...f7-f5 pawn break or ...Ne7 for a ...c5 break or ...c6 then ...d5 break.
Edit: I would still go in for the f3, e4 idea as white instead of exchanging on e4.
Originally posted by PhySiQ I wouldn't disagree. I think white looks better here. Do you agree that the position is very playable for each side?
Q
Yes, I do. Move 9 is still, IMO, the most critical in the game because, as you've seen, there are many vastly different positions that can result depending on what white does... it is not a very easy choice.
Originally posted by tomtom232 Yes, I do. Move 9 is still, IMO, the most critical in the game because, as you've seen, there are many vastly different positions that can result depending on what white does... it is not a very easy choice.
Agreed.
Things can unravel very quickly - Be4 is quite sharp, but not in a tactical sense. Its very positionally sharp... It demands clarity very early. There aren't many positions like it, forcing whites hand so early -- while black remains to absolutely flexible. That is of course the motif of the QID. However I think this individual line is very illustrative of that idea. Both for white, and for black.