dinsdag 17 maart 2009

Space and capacity

BDK's planning exercise and the follow up made me grab Michael Stean's classic "Simple chess" again. I especially felt the urge to read what Stean had to say about space and the advantage it is to suppose to offer. And again I was impressed by the clarity of his explanation. This a small part of his treatise of this subject:

Space is not an easily definable or recognizable concept. The visual impression you obtain by glancing at a position and estimating who seems to have the lion's share can be misleading. The following is nearer to the truth. Any given pawnstructure has a certain capacity for accomodating pieces efficiently. Exceed this capacity and the pieces get in each other's way, and so reduce their mutual activity. This problem of overpopulation is easy to sense when playing a position, it "feels" cramped. To take an example, compare the next two positions.

They do, of course represent the same position, but with two pairs of minor pieces less in the second case. In the first diagram black is terribly congested. There is no way he is ever going to be allowed to play b7-b5, while alternative methods of seeking some breathingspace by (after due preparation) ... e7-e6, or ... f7-f5 would compromise his pawnstructure considerably. White on the other hand can build up at leisure for an eventual e4-e5, safe in the knowledge that as long as he avoids any piece exchange, his adversary will never be able to free his game.

The second diagram is quite a contrast. The size of blacks forces is here well within the positions "capacity". As a result there are no spatial problems at all and black can very quickly seize the initiative by ... a7-a6 and ... b7-b5 or even by ... b7-b5 as a pawn sacrifice, e.g. 1 ... b7-b5 2 cxb5 a7-a6 3 bxa6 Rxa6 with tremendous pressure.
We see from this pair of positions that blacks structure is very good, but his capacity is small. Visually white has a spatial advantage in both cases, but in the second the eye flatters to deceive. In fact he is grossly overextended. A vast empire requires an army of equal proportions to defend it.

I have nothing to add to this, besides a glance at the position BDK gave us in his planning exercise.

Indeed, white has space? But why should this be an advantage, considering the explanation given above? It seems to me that blacks forces are will within the capacity of his pawnstructure

5 opmerkingen:

Anoniem zei


I wondered if black may have a temporary space disadvantage in the BDK position as the e7 pawn prevents him from quickly playing Ne7-d5. White on the other hand has both the c4 and d5 squares.
1. Ng5 might be a good first move for white, it prepares to answer ..RxR; BxR f6 with Bb3+ soon winning the b7 Bishop. It also threatens Ne4.

I wonder if black could have problems in this position. He would like to move his c6 knight (although to where is a question) so that he can cover e4 with his bishop but he may also wish to keep the knight on c6 to stop the plan mentioned in BDK's blog of a4 then a5 then PxP (or a4 a5 by black) to be followed by an eventual Nc4 (and/or white playing his king to b5). He must also worry about white playing Ne4 then Nxc5 PxN; BxP getting 3 pawns for the piece or if black plays e6 to prevent this:a3 then Nd6 Ba6; b4. White also has the threat of playing Bf3 to eventualy force Nd8.
For me the knight and b7 bishop seem to be in each others way which would imply a lack of space in blacks camp where as white has lots of room to manoeuvre. I imagine that black's position would be better if he could exchange off is c6 kight witch again implies that in this *particular* position he has one piece more than he needs.

Furthermore, it crossed my mind that if white plays passivley then black could undo his space trouble with e6 and Ne7.

Phaedrus zei

If white has an advantage her it appears to me that it is probably caused by the fact that he has the initiative and not because he has more space.

I thank you for your analysis, but will not go in to concretely. My aim in this post was not to go into the specifics of BDK's position, but to widen the perspective on the concept of space.

I hope you brought your thoughts on the position under BDK's attention. If not I encourage you to do so. What you say about the night on c6 certainly makes some sense. Even though in my view this has more to do with structure and piece placement than lack of space.

Blue Devil Knight zei

Very interesting stuff! Funny you mention those Stean quotes Phadrus as I think Coach B mentioned that passage explicitly in our last lesson. :) That is a great example.

I agree with anon in that it seems black does have a position in which his pieces' capacity is a bit smaller, cramped. However, it also isn't clear that white has enough tempi to exploit this. That is, his pieces aren't exactly perfectly mobile, fulfilling their missions either!

In many ways I feel I understand this position less now than before I posted it originally :)

Blue Devil Knight zei

I think one of the main take-home messages is that a really good spatial advantage is something you can really exploit (as Phaedrus mentioned at my blog originally).

You know the kind of games: you can take your time to build up an attack against his king, as his position is so cramped that he has no way to get things mobilized to stop you or intitiate a counterattack. When he is really cramped, you effectively have extra tempi and he is hopeless, caught in the constrictor's web.

My planning position obviously isn't such a clear-cut case of a boa-constrictor spatial advantage.

But space (i.e., more advanced pawns) also has other consequences: it ties down his pieces because of the threat of promotion. And the two senses work together. If he is really carmped, he can't move around much, and if my pawns are advanced then I am restricting his freedom even more as he must defend against pawn promotion dangers.

Clearly my position doesn't have that either. So my position, while technically an example of a space advantage, isn't a strong example of a case in which it can be turned into a clear and tangible advantage such as an attack.

However, with good play, and some cooperation from black, it could become like that. I want to play in a way that will make black restrict himself more, give myself more space, launch an attack, and win.

Unfortunately it isn't clear how to do that, especially with the rooks traded. So I think it would be fun to combine Azil's idea of keeping the rooks on, and my idea of starting a Kingside pawn storm.

I'm not sure it would be sound, though.

Phaedrus zei


I agree that white may have something to play for. But still I would think that this has more to do with the structure and his slight initiative. Ng5 and Bc4 as mentioned in some of the comments to your post are an example. They more or less provoke e7-e6 and this might give you an outpost.

I do not believe white has enough material to create a dangerous attack on blacks king.

The threat of promotion you mention is in a way indeed a potential threat. But, as often in chess, this kind of activity of the pawns also has a downside. Active pieces also tend to be more vulnerable. This is why we often shy away from advancing pawns. If they are stopped we risk to lose them.