Botvinnik Semi-Slav, The (Pedersen)

11 7 a4
1 d4 d5 2 c4 c6 3 lLlf3 lLlf6 4 lLlc3 e6 5
.i.g5 dxc4 6 e4 b5 7 a4 (D)
B
7 a4 is usually chosen by practical
players who are looking for something
not too theoretical but at the same time
want an interesting position. 7 a4
serves both purposes. White aims to
disrupt Black's queens ide while keeping
the 'threat' of e5 in the reserve.
Quick Summary
7 ... b4 (Line A) is a relatively new attempt.
After 8 lLlbl .i.a6 9 'ii'c1 c3 10
bxc3 .i.xfl 11 ~xfl lLlbd7 Black has
had good results in a few recent
games. If White does not find an improvement
here, this looks like the
easiest path for Black against 7 a4.
7 ... .i.b7 (Line B) is generally regarded
as the safest approach for Black
and usually leads to approximately
equal positions following 8 axb5 cxb5
9 lLlxb5 .i.xe4, while the other two options
for Black, 7 ... .i.b4 (Line C) and
7 ... 'tWb6!? (Line D), lead to much
sharper play. I have always thought
White to be much better in the line
7 ... i.b4 8 e5 h6 9 exf6 hxg5 10 fxg7
.l::.g8 11 h4!, but this might not be that
clear. The safest is 11...g4 (although
11...gxh4 is not that clear either),
when 12 lLle5 f5 13 h5 ':xg7 14 .i.e2
'tWg5!? seems to be about equal.
7 ... 'tWb6!? leads to messier positions,
with White having to justify his
pawn sacrifice. Here, I find the idea
of the small rook-lift after 8 .i.xf6
gxf6 9 i.e2 a6 10 0-0 ':a7!? interesting.
Black intends to meet 11 d5 with
1l....l::.d7.
The Theory of 7 a4
1 d4 d5 2 c4 c6 3 lLlf3 tiJf6 4 lLlc3 e6 5
.i.g5 dxc4 6 e4 b5 7 a4
Now:
A: 7 ... b4 141
B: 7 ... .i.b7 142
C: 7 ... .i.b4 144
D: 7 ... 'WWb6 147
A)
7 ... b4 (D)