Tuesday, March 10, 2009

Could it be a picture in your mind?

Gavín Roche - Horton, Aragón v Casino Jaque, Aragón Team Championship, 7 March 2009, position after White's 30.g3.

Black's holding this more than comfortably against a player ranked a good hundred points above him and thinks he'll maybe have a punt at winning so he goes 30...Rd5 to which White responds with 31.Rxd5 exd5 32.Qf4.

There follows a short period of sparring: 32...Qc4 33.Qf6 Qc6 34.Qg5 d4 35.Re1 Qe6 36.Rd1 Rc5 37.Qd8+ Kg7

before the queens come off: 38.Qxd4 Qxe5 39.Qxe5+ Rxe5 bringing about the following position

in which Black is confident that he can meet 40.Rd6 with 40...Re6, because if the rooks are exchanged he'll win the ending a pawn up.

If the rooks aren't exchanged, it'll be harder work, thinks Black, but he'll still have all the chances with his extra pawn. And as he awaits White's move, he has a look at the pawn structure to see what the best way to make progress might be.


Anonymous said...

Wow, a game that hasn't even been played yet, reported in advance on the blog. The wonders of modern technology, eh?

ejh said...

It's just an illusion...

Anonymous said...

So when did you make your gain - when the e6 pawn struck out on its own by recapturing on d5?


ejh said...

I think so. I think it's something to do with having acquired the passed pawn, yes. Somehow this translated in my mind as being a pawn up.

Like an overlap in a rugby game, I suppose, you've got a man over but you haven't actually got a man extra!

(For the record the game, and the match, were drawn.)

Anonymous said...

Sorry to spoil the illusion, but you have no passed pawn.

Tom Chivers said...

What an awful song, and worse video!

ejh said...

Sorry to spoil the illusion, but you have no passed pawn

Have a think about it....

Anonymous said...

I got pretty far in maths (tensors and all that), still remember in competition one step in a proof involved "25-7=12" (!). It was in my head and not on paper, but still.

Just a week ago I had as black (in outline):
I had seen the tactic a long time before, 1...Nxf3+ 2.Qxf3 Qxd2 wins a pawn, but I played 1...Qxd2 instead because "it wins a pawn *and* it forces a queen trade" (!).

Everybody does it sometimes, at least I hope it's not just me! What is interesting in your example is that the idea was so persistent, even once the position was on the board. Were you in time-pressure again?

ejh said...

You're always in time pressure with a Fischer clock.

(Well actually you're not, but when the sequence started I probably had a little more than five minutes to my opponent's one, plus thrity seconds a move.)

Not sure I understand your example - am I missing something?

Anonymous said...

The point is that ...Qxd2 won a bishop, not a pawn. Which I didn't realize until after I played it, and even then it took a couple of seconds.

I think when I follow through quickly on a calculated line, all the assumptions I made in my calculation persist for a while. Dangerous, as I only "visualized" the position, and I don't do that perfectly. (Plus as we have seen, I am not terribly good at arithmetic.)

It takes some effort to re-orient myself after, so that I "see" the chessboard instead of the visualized position. The longer the line and the quicker I play it, the worse this effect is.

ejh said...

The point is that ...Qxd2 won a bishop, not a pawn.

Ah, OK, I thought you (it was you?) were saying it was a mistake!

Actually, I may not even have noticed. Which may prove your point as well.

I find I have persistently difficulties in remaining aware of the material situation when calculating exchanges - so much so that I find myself saying "pawn up, knight for pawn down, rook and pawn for knight up, rook and pawn for bishop and knight" and so on at each nmove. This can't be healthy but if I don't do it naturally what else can I do?

Obviously in time trouble it will all fall apart and I'm bound to end up making exchanges and finding out I'm in a different material balance from what I thought. I'm sure there was another game not long ago where I suddenly realised I was two pawns down instead of one.

There was also a game some years ago against the Lancashire player Mike Surtees where in time trouble I didn't realise I was a piece up - and played for a draw. Perhaps I'll look that one up for a future post!

In the example here, it didn't matter very much in the end. But it mght have.