Botvinnik Semi-Slav, The (Pedersen)

THE MAIN LINE: 17 a3 17
~xd5 exd5 30 lIc7 b3 one has to find
31 ~g2!, which creates the crude but
very effective threat of 32 lIlc6 followed
by lIxf7. 31... 'Wa3 is then the
only move. Black needs to keep attacking
the posterior rook, thus being
able to meet 32lIlc6 with 32 ... 'Wa4!.
However, 32 lIc8+ ~xb7 33 lIlc7+
~b6 34lIxf7 looks winning for White.
White will simply exchange his f6-
pawn for Black's b-pawn, converting
to a winning rooks versus queen ending;
e.g., 34 .. :ti'd6 (what else?) 35
lIff8 b2 36 l:tb8+ ~a6 37 lIfc8 'Wxf6
38l:tc2, etc.
c) 22 ... e5 is, as against 21...'itc7,
the best try, but Black is then better off
with the king on c7. 23 b3! and now:
el) 23 ... ~h6 24 bxc4 l:txc4 25
~xa7+ ~c7 26 ~b6+ ~d7 27l:tadl+
'ite6 28 ~h3+ ~xf6 29l:td8! +-.
c2) 23 ... ~d6 24 bxc4 lIxc4 25
~xa7+ ~c7 26l:tfc1l:txcl + 27lIxc1 +
~d7 28 .!Db6+ ~e6 29 lIc6 and White
wins.
c3) 23 ... cxb3 24l:tfcl ~d6 25 ~xd4
exd4 26 lIc6 d3 27 lIacl 'Wxb7 28
l:txd6 'ii'b5 29 .!Db2 l:tc8 30 lIel a5 31
.!Dxd3 a4 32 l:td5 'Wb6 33 .!De5 and
White eventually won in Meissner­
Skomorokhin, Brno 1993.
c4) 23 ... c3 24 lIadl! ~d6!? (or
24 ... ~h6?! 25 ~xd4 exd4 26 l:txd4
c2?! 27 l:tc4 cl'ii' 28lIfxc1 ~xcl 29
l:txc1 lId8 30 .!Dc5 a5 31 h4