A Perennial Trap Claims Another Victim
See here.
Sunday, August 13, 2006
An Interesting Move-Order Trick in the Caro-Kann
The following sequence introduces the absolute main line of the Caro-Kann Defense: 1.e4 c6 2.d4 d5 3.Nc3 (or 3.Nd2) dxe4 4.Nxe4 Bf5 5.Ng3 Bg6. From here, most of the games continue 6.h4 h6 7.Nf3 Nd7 8.h5 and so on.
But what's the reason for this funny stutter-step approach by the h-pawn? Why not 7.h5, or 6.Nf3 first and then h4 and h5? One conjecture, which may or may not be compelling, is that White wants to induce ...N(b)d7 as soon as possible, perhaps for as many as three reasons. First, White can then play Bf4 without worrying about ...Bd6 in reply. Second, if Black can achieve ...c5 before playing ...Nd7, the knight could instead reach the more active c6 square. And third, an open d-file with the knight back on b8 facilitates exchanges favorable to Black.
Thus returning to the variation above, 6.h4 induces ...h6, as Black doesn't want to give up this bishop for a knight (if he did, he wouldn't have retreated to g6!) and 6...h5 weakens Black's kingside without any commensurate gain. Then 7.Nf3 encourages 7...Nd7, as a move like 7...e6 allows White to play 8.Ne5. Black can try to remove it (after 8...Bh7 9.Bd3 Bxd3 10.Qxd3) with 10...Nbd7, but 11.f4 maintains it, as 11...Nxe5 12.fxe5 gives White nice prospects along the f-file.
Black has been playing the provocative 7...Nf6 every so often the past 5-10 years (though still far less than 7...Nd7), and while it sometimes transposes to 7...Nd7 lines, it can have an independent cast as well. (For example: 8.Ne5 Bh7 9.Bd3 Bxd3 10.Qxd3 e6 11.Bd2 Nbd7 12.f4 etc.)
Still, 7...Nd7 is the most common move, and then White plays 8.h5 and we're off on the road most traveled. But the foregoing doesn't explain the reason for 6.h4 rather than 6.Nf3. Granted, there are some minor, trappy lines like 6.h4 h6 7.N1e2 (or 7.Nh3) followed by 8.Nf4, but they're pretty rare, considered second-rate against best play (but Caro players had better know them!) and thus not likely to be the full story.
I'm not sure that there is a full story, but if there is, I recently discovered at least another piece of it a few days ago, when I came across the game Antoms-Rausis from a rapid event in Latvia. Antoms played 6.Nf3, Rausis played 6...Nf6, and after 7.h4 uncorked 7...Nh5!? This move was new to me, but as it turns out it has a prehistory. The Mega2006 database gives 29 games with the move, going back to Koblencs (aka Koblentz)-Ratner, Moscow 1945.
And it's not bad, either! The White h-pawn is stopped, without Black having to create any potential kingside weaknesses, and White must either accede to the deformation of his pawn structure or else swap, placing the Black bishop on the very good h5 square.
Without any further ado, here's Antoms-Rausis.
But what's the reason for this funny stutter-step approach by the h-pawn? Why not 7.h5, or 6.Nf3 first and then h4 and h5? One conjecture, which may or may not be compelling, is that White wants to induce ...N(b)d7 as soon as possible, perhaps for as many as three reasons. First, White can then play Bf4 without worrying about ...Bd6 in reply. Second, if Black can achieve ...c5 before playing ...Nd7, the knight could instead reach the more active c6 square. And third, an open d-file with the knight back on b8 facilitates exchanges favorable to Black.
Thus returning to the variation above, 6.h4 induces ...h6, as Black doesn't want to give up this bishop for a knight (if he did, he wouldn't have retreated to g6!) and 6...h5 weakens Black's kingside without any commensurate gain. Then 7.Nf3 encourages 7...Nd7, as a move like 7...e6 allows White to play 8.Ne5. Black can try to remove it (after 8...Bh7 9.Bd3 Bxd3 10.Qxd3) with 10...Nbd7, but 11.f4 maintains it, as 11...Nxe5 12.fxe5 gives White nice prospects along the f-file.
Black has been playing the provocative 7...Nf6 every so often the past 5-10 years (though still far less than 7...Nd7), and while it sometimes transposes to 7...Nd7 lines, it can have an independent cast as well. (For example: 8.Ne5 Bh7 9.Bd3 Bxd3 10.Qxd3 e6 11.Bd2 Nbd7 12.f4 etc.)
Still, 7...Nd7 is the most common move, and then White plays 8.h5 and we're off on the road most traveled. But the foregoing doesn't explain the reason for 6.h4 rather than 6.Nf3. Granted, there are some minor, trappy lines like 6.h4 h6 7.N1e2 (or 7.Nh3) followed by 8.Nf4, but they're pretty rare, considered second-rate against best play (but Caro players had better know them!) and thus not likely to be the full story.
I'm not sure that there is a full story, but if there is, I recently discovered at least another piece of it a few days ago, when I came across the game Antoms-Rausis from a rapid event in Latvia. Antoms played 6.Nf3, Rausis played 6...Nf6, and after 7.h4 uncorked 7...Nh5!? This move was new to me, but as it turns out it has a prehistory. The Mega2006 database gives 29 games with the move, going back to Koblencs (aka Koblentz)-Ratner, Moscow 1945.
And it's not bad, either! The White h-pawn is stopped, without Black having to create any potential kingside weaknesses, and White must either accede to the deformation of his pawn structure or else swap, placing the Black bishop on the very good h5 square.
Without any further ado, here's Antoms-Rausis.