Botvinnik Semi-Slav, The (Pedersen)

UHLMANN'S 16 'f1.b1 45
19 tLJa4 'iWb5 20 axb3 exd5 21 l:tc1
~b8, White can, according to Piket,
claim an advantage by 22 lVd2! (instead
of the game's 22l:tel).
The powerful queen
While the open b-file might be Black's
biggest concern, one should also be
wary of the possible consequences following
conceding the as-hI diagonal.
White's knight sometimes gets access
to d5 or e4 but more frequently White
moves his queen up to d5, which is a
very powerful post, whence it not only
attacks pawns on c5, c4 and f7, but
also pinpoints the possibility of a check
on as. The following example shows
that Black must be on his utmost alert
to parry all threats:
B
Kasparov - Kramnik
New York peA rpd 1994
19 ... .txe7
Black takes the opportunity to save
his rook but nowadays 19 ... .th6 is
more popular.
20 fxe7 l:tdg8
Here 20 ....td3! has been shown to
be the best defence. Black walks a
tightrope to avoid defeat after 21 tLJe4
i.xbl! 22 tLJd6+ ~c7 23 .tf4 but
Kramnik managed to do so against
Topalov in Dortmund 1996.
21 tLJe4! l:tg6
Black has to defend against tLJd6+.
Now Kasparov took his chance to recoup
some of the material investment
with 22l:txfl ? but he later pointed out
that 22 lVaS+ would have given Black
serious problems. One line continues
22 ... tLJbS 23 .tf41Vb7 24 'ir'xb7+ ~xb7
25 ~xfl ~c6 26 l:tdl tLJd7 27 tLJd6!
:'e6 2S tLJxf7 and White wins. He
threatens both 29 tLJxhS and 29 tLJdS+.
Quick Summary
There are a few interesting things to
note about Uhlmann's 16 :bl. First of
all, I think the briefly popular 16 ... .th6
(Line A) should be disregarded in
view ofPiket's idea 17 .txh6 :'xh6 IS
b3!, which looks very strong.
Hence, the key question is whether
White can find any advantage following
16 .. .'ii'a6 17 dxe6 .txg2 IS e7
.txfl. Line Bl, 191Wd5, seems close
to a forced draw, but 19 'iitxfl (Line
B2) is very interesting. White seems to
hold the better chances after 19 ... 'ir'c6
20 exd81W+ 'iitxdS 21 tLJd5 :'xh2 22
'itgl :'hS 23 .tf4! but 19 ... .th6!? (a
move which has hitherto been ignored)
deserves attention. However,
there is virtually no practical experience
with this move.