Once I encountered an opponent who used a very early a6 in his Sicilian Opening.
[FEN ""] 1. e4 c5 2. Nf3 a6
What could be his objective with this move and how should I have encountered it?
This is called the O'Kelly variation of the Sicilian.
If white plays normally (i.e.
White's best plan is to play either
An unambitious plan for white would be to play into a closed Sicilian - in the closed Sicilian, black frequently plays a6-b5 in order to get counterplay on the queenside. Furthermore, in the closed Sicilian, tempi matter a lot less because the position will not change radically from one move to the next.
As I understand it, the purpose of
It seems premature, because white might not want to go there anyway (for some time). Meaning that it could easily become a wasted move.
As White, I would concentrate on king side development, knowing that b5 was "off limits," but not caring, because I have "better" things to do.
One disadvantage of a6 is that Black may want to play a5 later to try to "chase" a White knight on b3. But if he does so, he would have wasted a move with a6.