This was written for the July issue, but appeared later due to a mishap in
publication.
Since it was published, two people have sent me corrections to my analysis. I
have included these; they are marked by square brackets, [like this].
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When I watched the following game, I realized that it would be very instructive
to play over. After the time control it looks like a draw, but some time in
the next 20 moves it goes over to a win for Black. Can you figure out where?
White: Tom Martinak, Pitt I
Black: Jim Booth, Double Trouble I
Pittsburgh Chess League, February 1996, board 2
Benko gambit declined
1 d4 Nf6
2 c4 c5
3 d5 b5
4 Nf3 g6
5 a4
If Black now plays 5 ... b4, the game tends to a draw, because the whole
queenside is out of action. Instead he playes a more double-edged
continuation.
5 ... bxc4
6 Nc3 d6
7 e4 Bg7
8 Bxc4
White might consider the well-known Benoni maneuver 8 Nd2 and 9 Nxc4. Black
could not easily trade the white-squared bishops; White's knight would find
a strong square; and White's f-pawn would be available to advance to f3 or
f4 in some lines.
8 ... O-O
9 h3
A waste of time.
9 ... Ba6
10 Bb5!? Bxb5
Is White's pawn on b5 going to give him an advantage? If Black had thought
so, he might have tried 10 ... Ne8. After 11 Qe2 Nc7 12 Nd2 Qc8, it appears
that White will eventually have to retreat or exchange the bishop.
11 axb5 Nbd7
12 O-O Nb6
13 Qe2 Ne8
14 Bg5 h6
15 Be3 Nc7
16 Nd2 Qd7
17 Ra5 Nc8
18 Nc4 Rb8
19 Qd2?
White could now defend the pawn with 19 Na3. His pieces would then be
awkwardly placed, but not more so than Black's. Instead, he falls victim to
the "Benoni delusion", thinking that his beautiful center will compensate
for a pawn.
19 ... Kh7
20 e5 Nxb5
21 Ne4 f5!
22 exf6 exf6
23 Bf4 f5?
Simply 23 ... Rb7 maintained a solid defense. 24 Ncxd6 Nbxd6 25 Nxc5 Qf7
26 Nxb7 Qxb7 looks OK for Black.
24 Nxc5 Qc7
diagram:
1rn2r2
p1q3bk
3p2pp
RnNP1p2
2N2B2
7P
1P1Q1PP1
5RK1
25 Na6?
The position is now extremely complicated. A variation that shows some of
the possibilities is 25 Ne6 Qxc4 26 Nxg7! (but not 26 Nxf8+ Bxf8 which leaves
White with no compensation) 26 ... Kxg7 27 Bxh6+ Kg8 28 Bxf8 Kxf8 29 Qh6+ and
Black's exposed king is doomed.
In this variation Black might save himself by 26 ... g5, though his position
doesn't look entirely healthy after 27 Ne6 (if 27 Bxg5 hxg5 28 Qxg5 Rb7,
Black escapes perpetual check and wins) 27 ... Rg8 28 Rc1 and 29 Bh2.
The insertion of 26 Rc1 doesn't appear to change things, but it sets a trap:
25 Ne6 Qxc4 26 Rc1 Qe4? (Qb3 is correct) 27 f3! Bd4+ (forced, to save the
queen) 28 Kh1 Qxd5 29 Nxf8+ winning.
[Ken Davenport points out that in the variation 25 Ne6 Qxc4 26 Nxg7 g5
27 Bxg5 hxg5 28 Qxg5, my 28 ... Rb7 probably loses to 29 Ne6. There is no
good square for Black's rook, as 29 ... Rg8 and 29 ... Rh8 both lead to
mate. Also 28 ... Rf7 is very shaky due to 29 Nxf5 or 29 Ne6. 28 ... Qxd5
may be safest although 29 Ne8 Qf7 30 Qh4+ is a perpetual.]
White can also consider 25 b4, but this move only serves to prepare a retreat
of the knights, and is not better than 25 Ne6. The move actually played
appears to win the exchange, but backfires horribly.
25 ... Qxc4
[Tom Martinak points out that White should now play 26 b3! After 26 ... Qxb3
26 ... Qxb3 27 Nxb8 Bc3 28 Rxb5 Qxb5 29 Qxc3 Qxb8 30 Rc1 White has more
than enough for the pawn, although Black may hold. In this variation
27 ... g5 may be an improvement for Black, because 28 Be3 f4 traps the
bishop. Thus 28 Bh2 is necessary, and after 28 ... Bc3 etc., Black's
defense is easier than in the first variation, although it's probably
still a draw.]
26 Nxb8 Nd4
Black threatens 27 ... Ne2+ or 27 ... Nb3. If 27 Re1 Nb3, White's queen
cannot retreat to e1, and White loses a whole rook. If 27 g3 Nf3+ wins the
queen.
27 Ra3 Ne2+
28 Kh1 Ng3+
28 ... Nxf4 may have been better. White gets some counterplay; an example
of this is 29 Rc1 Qe4 30 f3 Qd4 31 Qxd4 Bxd4 32 Ra4 Be5 33 Rc7+ Kg8
34 Nd7 Rd8 35 Rxf4! Bxf4 36 Nf6+ with perpetual check. However, this line
is more cute than accurate: Black gets out with 34 ... Nxd5! If White
cannot keep up his initiative, Black will end up with a winning material
advantage. The variation chosen leaves material equal, but Black has some
surprising chances.
29 fxg3 Qxf1+
30 Kh2 Re8
30 ... Qb5 31 Nc6 Qxb2 32 Qxb2 Bxb2 33 Ra2 and 34 Nxa7 is no better.
31 Re3 Re4!?
32 Rxe4 fxe4
33 Nc6 Qd3
34 Qxd3 exd3
35 Bc1??
The last move of the time control. 35 Nb4 was necessary. After 35 ... Bxb2
36 Nxd3 Ba3, Black is better, but it's still a fight.
35 ... Nb6??
35 ... Bxb2!
36 Nb4 d2?
36 ... Bxb2 was still stronger: 37 Nxd3 Bxc1 38 Nxc1 Nxd5. The game now
enters a new phase. Black's passed a-pawn is potentially dangerous, but it
seems like an impossibly long journey to the eighth rank.
37 Bxd2 Bxb2
38 Nc6 Nc4
39 Bb4 a6
40 g4 Kg7
41 Kg1 Ba3
42 Bc3+
42 Bxa3 was safer. It's hard to believe that White could not then defend
the knight endgame.
42 ... Kf8
43 Kf2 Nb6
44 Bd2 Nxd5!?
Other lines, such as 44 ... g5 45 h4 or 44 ... h5 45 gxh5 gxh5, leave Black
with advanced and potentially weak pawns on the kingside.
45 Bxh6+ Kf7
46 Bd2 Ke6
diagram:
8
8
p1Npk1p1
3n4
6P1
b6P
3B1KP1
8
47 h4 Nf6
48 Kf3 d5
49 Be1 Bd6
50 Ba5 Ne4
51 h5 g5
52 Nd4+
White is angling for counterplay based on his h-pawn, but it's not clear that
he wouldn't have been better off just sitting tight.
52 ... Kd7
53 Nf5 Bc7!
54 Bb4 a5
55 Ba3 Be5!
Alertly seizing an important diagonal.
56 Ke3 Nf6
57 Kf3
Compare this with the position before White's 47th move. White's adventure
on the kingside has been a disaster.
57 ... a4
58 Ne3 Ke6
59 Nd1 Nd7
60 Nf2 Nb6
61 Nd3 Nc4
62 Bc1 a3
63 Bxg5 a2
64 Bc5+ Kf7
65 Nb3 Na5
Resigns