Material and exchange tendencies

[simonhue]

Hi,

I'm currently doing some work on calculating the average material per move (exchange tendencies) for chess players.

Is anybody aware of any work done in this direction beyond what I could find in the paper Computer Analysis of World Chess Champions?

Also I would be interested to point me if you know that any of this was discussed somewhere: In the paper from 2006 the authors calculated the exchange tendencies for several world champions however I believe that in their work they assumed in the measurements that the material after the game has ended is zero. Thus the conclusions in the paper (That, e.g. "Kramnik obviously dealt with less material on board") are possibly incorrect, or at least ambiquous. Counting the material after the game has ended as zero leads to lower average numbers, for which one explanation could be tendency to simplify positions, but also just that the player has played shorter games (by faster accepting draws, resigning, or making his opponent to resign earlier).

(P.S. I hope this is the right forum section for those kind of question).

[User923005]

In order to obtain favorable material exchanges, computers use material imbalance tables as pioneered by Larry Evans and Rybka.
It's all over the internet. See, for instance:
http://www.chess.com/article/view/the-e ... ry-kaufman

It does not matter what the opponent likes, as long as you only choose exchanges that benefit you.

[User923005]

Of course, that should be Larry Kaufman rather than Larry Evans

[simonhue]

Hi,

Trying to improve how material value of pieces is calculated is interesting point, I can try to rerun the analysis with Larry Kaufman's formula, or some of the others (I like Larry's approach, as it's rather practical, i.e. based on many tournament games).

The point here I believe, however is not really how accurate you have calculated the material difference, but still the inclination to simplify position (And of course this has nothing to do with is such player stronger or weaker). Just comparing the super GMs, over more than 1000s games for each, the positions of Giri e.g. vs. the positions of Topalov (both at move 20 and 40), Giri's positions has on average 3 points (pawns) less material. I don't know for Giri, and might be a bit far fetch to conclude this, but this seems to me consistent with the sayings that Topalov is more of a tactical player, who prefers more complex positions (OK, this is too far fetched, as complexity of position you don't get out of the material, but rather with algorithms utilizing the difference of the best engine move with second best, etc.).

On the other hand for weaker players you can see much bigger differences (upto 6, or 9 points) at move 20/40 so you can really spot players that really like to exchange pieces and simplify positions.

[hyatt]

This seems to be a psychological issue. Do you like to attack or defend against attacks? Do you like complicated positions, or do you like to use your endgame skills/knowledge to grind out a slow but clear win? I've always been a tactical/attacking player. I've known some that play boring (but incredibly solid) chess. To each his own. Some football teams like the old 3 yards and a cloud of dust approach. Some like the spread offense scoring a point a minute or better.