Thursday, February 21, 2008

How hard is it to spot a transposition?

Bear with me, for this is not so complicated as the variation it discusses. Consider the following line and the position that it brings about:

1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 e6 5.Bg5 dxc4 6.e4 b5 7.e5 h6 8.Bh4 g5 9.Nxg5 hxg5 10.Bxg5 Nbd7 11.exf6 Bb7 12.g3 Qb6 13.Bg2


There are various different ways of reaching this much-played and complicated position, and more than one way of proceeding from it: but if we take the advice of Steffen Pedersen (The Botvinnik Semi-Slav, Gambit, 2000, p.99-100) then Black should castle queenside before advancing the c-pawn. This is because, after 13...c5, White doesn't have to play 14.d5 but has a better move in 14.dxc5!. Pedersen explains:
After 13...c5 White can of course transpose to the main line, Chapters 2-4, with 14.d5 O-O-O 15.O-O b4, but with (sic) 14.dxc5! Bxc5 15.O-O is a good alternative.
Now Pedersen considers both 15...Bxg2 16.Kxg2 and 15...O-O-O 16.Qe2 good for White. More specifically, he describes the latter as "a favourable version of Line B22", which variant crops up on the following page and goes 13...O-O-O 14.O-O c5 15.dxc5 Nxc5 16.Qe2. Oddly, though, in a note at Black's fifteenth he actually gives a game which proceeded 15...Bxc5 16.Qe2.

Now as far as I can see, 13...O-O-O 14.O-O c5 15.dxc5 Bxc5 16.Qe2 gives precisely the same position - with precisely the same last move - as 13...c5 14.dxc5 Bxc5 15.O-O O-O-O 16.Qe2. It's just that in the second case the castling comes after the captures, rather than vice versa. Which makes it not so much a "version" of another line but a note within it. This is a little clumsy. Given that page 100 and page 101 are facing one another, it means in effect that Pedersen is giving a line on one side of the fold that he doesn't realise he's also giving on the other.

Well, you may say, never mind, we can still follow what he's saying and moreover, Wells (The Complete Semi-Slav, Batsford, 1994) concurs, going so far as to mark 13...c5?! as dubious, and commenting:
14.dxc5! really looks promising, as Black cannot follow up...Nxc5 with ....O-O-O for legal reasons.
So it's all well and good, and next time, I shall know this: 14.dxc5 is the move to play and 13...c5 is not.

But it does beg the question - why, if 13...c5 is inexact, does Pedersen, at the start of the aforementioned chapters 2-4, give the standard move order as 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 e6 5.Bg5 dxc4 6.e4 b5 7.e5 h6 8.Bh4 g5 9.Nxg5 hxg5 10.Bxg5 Nbd7 11.exf6 Bb7 12.g3 Qb6 13.Bg2 c5 14.O-O - thereby missing, on several prominent occasions, precisely the crucial detail he is careful to point out later?

4 comments:

ejh said...

For what it's worth, my assumption is that the "correct" line is supposed to be 12...c5 and only then 13...Qb6. Why it wasn't actually presented this way, only Pedersen and Gambit (the best of the UK chess publishers, for my money) can tell us.

As it is, the unsuspecting player of the line would only know there was a problem if he or she happened upon a couple of notes in a section about sidelines.

The complaint, by the way, has nothing to do with my game played on Saturday and featured in the blog this week - I looked at the book only after the game, having prepared another opening entirely from the one my opponent produced....

Anonymous said...

This often happens with books. Sometimes i think it stems from the days when a lot of the lines were sourced from things like ECO which often omitted transpositions when showing 'unusual' lines.

My favourite, because i play it, was a Nunn (?) and Burgess book on the Najdorf Sicilian, which included the line 6. Bg5 Nc6 with the comment "transposes into a dubious line of the Richter-Rauzer".

The usual move order in the Richter-Rauzer is 5... Nc6 6. Bg5 e6 7. Qd2 a6.

The "dubious line" (given in ECO) is 5... Nc6 6. Bg5 a6 7. Qd2 Nxd4 etc. ECO didn't feel the need to point out that 7... e6 is a direct transposition to the mainline, and the book in question didn't notice this rather crucial point.

Richard

ejh said...

I should say that I don't wholly blame the writer for this sort of thing. Books aren't written in a neat sort of way from the first page to the last and it can often be that you revise one section and then overlook that this impacts on any section entirely.

Moreover as anybody who's ever written a book will tell you, after a whle it's really hard to spot your own errors because your eye naturally skips over material it's seen dozens of times already.

It's to a large degree a problem which ought to be caught at the copy-editing stage. Which I'm convinced that, in the case of at least one chess book publisher*, barely exists at all.

But either way, this is a poor effort. It's not just a side-variation, it's the main line.

(* = not Gambit)

gorckat said...

Books aren't written in a neat sort of way from the first page to the last and it can often be that you revise one section and then overlook that this impacts on any section entirely.

Wow. Someone needs to invent a word processor with referential integrity (the thing in a database that changes every record affected when info is updated, basically).

That would probably border on AI and put editors out of work. Not such a bad thing!