Botvinnik Semi-Slav, The (Pedersen)

4 Uhlmann's 16 z:.bl
1 d4 d5 2 c4 c6 3 It:)f3It:)f6 4lt:)c3 e6 5
i.g5 dxc4 6 e4 b5 7 e5 h6 8 i.h4 g5 9
It:)xg5 hxg5 10 .txg5 It:)bd7 11 exf6
i.b7 12 g3 'ii'b6 13 i.g2 c5 14 d5
0-0-0150-0 b416 l:tbl (D)
White from opening the b-file. A further
example of what might then happen
is:
B
B
For many years Uhlmann's 16 l:tb1
failed to attract the attention it deserves.
Despite a few very nice wins
by the German (former East German)
grandmaster in the early 1980s, it is
not until the late 1990s that the system
was practised regularly. Shirov describes
it as not very logical but terribly
dangerous, and indeed it is. Its
immediate justification may be seen if
Black accepts the sacrifice by capturing
the knight on c3, i.e. 16 ... bxc3 17
bxc3 'ii'a6 18 l:txb7! followed by 19
dxe6 with a strong attack. In general
Black should do his utmost to prevent
Piket - lIIescas
Dos Hermanas 1995
White has just met 16 ... i.h6 with
17 i.xh6 l:txh6 18 b3!, in the hope of
opening the b-file. This may be the
case if Black chooses the greedy, albeit
consistent, 18 ... bxc3?!, when 19
bxc4 'iVa6 20 l:txb7 1i'xb7 21 dxe6 is
terribly dangerous. The key point is
that 21...1i'b2?! is met by 22 e7! (22
exd7+ is less clear). Then 22 ... :e8 23
i.c6 'iVd2 24 'ii'b3! 1i'b2 25 i.xd7+
led Black to resign in Khalifman­
Galkin, Elista 1998. There are other
options for Black, of which the best attempt
is probably 18 ... cxb3, but after