What is the purpose of 8.a3 here?

eddins
eddins
May 7, 2011, 5:39 PM |
4

Black has just played 7...a6. This position appears 3 times in the ChessBase 2009 reference database. In each game, White played 8.a3. (White player ratings were in the 2300s and 2400s.)

Can anyone help me understand the purpose of 8.a3 here?