Botvinnik Semi-Slav, The (Pedersen)

UHLMANN'S 16 'J:.b1 49
e3) 21 'iWe2 is more resilient; Black
must then play accurately:
e31) 21...'iWxa2? 22 .tf4+ (Black
may survive 22 ~xg2 'ir'xbl 23 .tf4+
~b6!?) 22 ... J.d6 (22 ... ~b6 23 'iWc2 ±)
23 .txd6+ l:f.xd6 241:txh8 'iWxbl + 25
~xg2 c2 26 'iWe7+ and White wins.
e32) Black should investigate the
disruptive 21...c2. For example, after
22 'iWxc2 the idea from 'e2' above,
22 ... 'iWc6, is less powerful: 23 .tf4+
.td6 24 .txd6+ l:f.xd6 25 l:f.xh8 .te4
26 'iWxc4 J.xb127 'ili'xf7+;t. Nonetheless,
Black can try 22 ... J.d5 23 J.f4+
~c6, which looks risky but is far from
over.
f) 18 ... fxe6!? 19 ~xg2 gives Black
two options:
f1) 19 ... 'iWc6+ 20 lUe4 lUe5 21 'iWe2
lUd3 (the serni-active-looking 21 ... l:f.d4
22 f3 lUd3 is worse since after 23
l:f.edl Black is tied up with no real
prospects of improving his position)
22 'iWf3 (22 l%edl!? lUxf2 23 'ili'xf2
'iWxe4+ 24 ~gl1:td5 is rather unclear
but probably not worse for Black,
whose pawn-mass on the queens ide
counts for just as much as White's
three passed pawns on the kingside)
22 ... ttJxel + (22 ... lUe5!? is worth considering,
but an even better option is
22 ... l:f.d5 !, which introduces the idea
of ... l:f.f5, a not uncommon activation
of this rook) 23 l:f.xel. The position is
unclear but probably quite good for
White. The exchange sacrifice has
served to remove the knight from d3,
and with White's terribly strong centralized
knight on e4, Black has few
chances of pushing his queenside
pawns forward, while White almost
has a clear run in on the kingside.
f2) 19 ... bxc3 20 bxc3 'ii'c6+ 21
'iitgl J.h6 (2l...ttJb6 22 'ili'g4 presses
against the e6-pawn and is rather uncomfortable
for Black) 22 'ili'g4. Black
can now try:
f21) 22 ... l:f.dg8 23 'iWxc4 l%xg5 24
1:txe6 'ili'f3 25 'ili'a6+ ~d8 26 l:f.d6! and
White seems to win in view of the
threat l:f.b8+.
f22) 22 ... J.xg5! is more prudent.
23 l:f.xe6 'ii'd5 24 'ili'xc4 has the finesse
that 24 ... 'iIt'xc4? 25 l:f.c6# is mate, but,
of course, Black can defend by means
of 24 ... lUb6!, when I do not see anything
convincing for White.
Returning to the position after 18
e7 (D):
B
18 ... .txfl
Recent top-level games suggest that
this is close to being a forced draw.
The alternative is 18 ... .ta8!?, but it is
not clear whether Black can really
equalize here: