Tuesday, October 25, 2005

Bishop Fetishism

I have criticized myself in an earlier post of the same subject, and after the Winterthur Chess Week Open I must come back to this issue. Preferring Bishops over Knights, as Tempo does, is completely ok. What I call Bishop Fetishism is to make weak moves because of this preference. I did twice in my last tournament, and once it was the beginning of loss in the opening, and once it was a direct cause of loss in a late middlegame.

Let's assume for the moment that a single Bishop values more than a single Knight (it does not), then we speak of a maximum of 0.25 pawn units (half the bishop pair bonus of 0.5). In general, of course, as a mean value of 1 million positions. Making one passive move loses 0.25 pawn units, giving away the hypothetical maximum plus value of the Bishop. In reality, in most cases, you will be not equal after a passive move, but considerably down by at least 0.25. In many cases a weak move starts a chain reaction of more weak moves, and this is what you will end up with: A position where your Bishops have nothing to pin and where the opponent's Knights have wonderful perspectives to fork your weaknesses and to occupy outposts.

Here is my list of bad bishop moves:
  • Developing on a passive square to prevent being attacked or traded away.
  • Not recognizing that the Bishop will become a bad one and missing the opportunity to trade against a strong piece.
  • Using too much time to maneuver the Bishop to its best square.

And these are the jobs I think a Bishop should do in a game:
  • Pin or x-ray a target
  • Work together with a Queen in a diagonal battery
  • Work together in a Bishop Pair, controlling open space
  • Eliminate dangerous or guarding Knights
  • Destroy the castle of the opponent King
  • Being a life insurance in an opposite coloured endgame with pawns down


At 3:24 PM, Blogger CelticDeath said...

Silman enhances the bishop vs. knight debate with further guidance:

1. N on ranks 1 - 3 < B
2. N on 4th rank = B
3. N on 5th rank = R
4. N on 6th rank > R

Of course, there are other questions that need to figure into the evaluation - is the knight on the rim, is the bishop bad and/or inactive, etc.

At 5:29 PM, Blogger Mousetrapper said...

In my last game I had to decide to play a N or a R to 6th rank. My intention was R, but computer analysis showed later that N would have been better. I think the point is that a N is much better on 6th rank, but a R is good anywhere on an open file or rank. R on 6th would have been better if my opponent did not see the tactic threat, but because his cellphone rang ...

Silman's point 4 seems rather too optimistic for the N. Do we see masters sac the exchange all the time against N on 6th? Certainly not!

Also it should be added that it must be an outpost not to be attacked by pawns.

At 12:44 PM, Blogger Druss said...

The bishop pair definitely has some value. A pair of bishops vs a B + N is an advantage, often worth about 0.5. A lone B vs a N is a different matter, this depends on the position.

A N is good if it's on an outpost. B are good in endgames with pawns on either side of the board. It depends on the situation.

At the moment I really like knights because they are great for tactical shots. I know some people at our level think that bishops only have one use ... getting rid of knights!

As with most things, you've got to know how to use them. I got really into Silman and analysing the imbalances between N & B. But then I found I was loosing too many games because I'd miss some tactical combination because I was spending too much thinking time on establishing my excellent knight on an outpost on the sixth rank.

My feeling at the moment is that while it is useful to know some of this stuff, you don't really have to master it until you are quite a high level. Indeed, you may end up missing tactical stuff if you think too much about it. So I'm not going to bother until I've conquered the tactical stuff.

Fischer is a master of knights and bishops ... running through his games is a great learning experience.

At 2:12 PM, Blogger Temposchlucker said...

In doing tons of problems I noticed that with a king attack, the bishops are very often placed in the opposite corner. For example black king on g8,
white bishop(s) on b1 and c3.
So I always try to place my bishops there.

With the bishoppair, I always force to open up the position, even by saccing pawns. Because in an open position the hostile knights don't have a good place to stand and the rooks can't hide, so the chance of winning the exchange increases.

At 6:08 PM, Blogger Mousetrapper said...

My two best wins at Winterthur Chess Week Open both started with my B removing an opponent N and then launching a N attack. In the decisive tactic the N always played the key role. That's why I love knights.

At 9:10 PM, Blogger Pawn Sensei said...

Wasn't there an Grandmaster a long time ago that had the same fetish? They said his opponents knew that and would use it against him. I can't remember which one at the moment.



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