Sunday, July 28, 2013

my favorite lessons 6: bishop takes knight?

Kids love knights. I find myself reminding students 10,000 times a year that bishops are usually better than knights, and they need to have a good reason to trade a bishop for a knight. To overcome their natural tendency to favor the knight, I like to give a lesson directly on the subject.

So what is a good reason to trade bishop for knight? Most of the time, you should either be
1) winning a pawn,
2) opening up a king (in a situation where it's realistic to attack) or
3) creating a real pawn weakness that you can attack.
It's also ok to trade if your bishop is bad and you have no good retreat square for it.

Of course, there are some situations that don't fall into these categories, but I make it clear that students are responsible to me for having a good reason.

I explain to the class that I'm going to give them 8 positions and they have to tell me if white should trade the bishop for the knight, or not. Notice that in most (5/8) positions, the answer is simply no, you should not take the knight.

Here they are: (or here if you'd prefer a cbv file)

1. No

2. No

3. No

4. yes, since white can follow up by taking on e5

5. yes, because white creates a serious weakness: doubled isolated pawns on a half open file. Notice that White needs to continue correctly: 1. Bxc6 bxc6 2. Na4! (otherwise black will get rid of his weakness by playing 2....c5), followed by Rac1 and either Qc2 or doubling rooks on the c file.

6. no


7. Yes, because it opens up black's king. White can follow up by castling queenside or playing Qd2 to attack the weak h6 pawn. Point out that after 1. Bxf6 gxf6 2. Qd2 Kg7 3. 0-0-0, white doesn't have to be afraid of 3...Bxf3, since opening the g- file only makes black's king less safe.
8. No. What white would actually like to do here is play Bg5-h4-g3 and try to trade off black's excellent dark squared bishop.


Marc Widmaier said...

Hi Elizabeth,
One of my biggest problems with kids from 0 to 1000 is to prevent them from making every even trade available. I think kids love to take pieces because it feels like they are doing something. Do you have a future lesson for this problem?
Love the lessons, they are excellent! You must write a book one day about teaching.

Joseph Knecht said...

What do you think about Larry Kaufman's finding ( that bishops and knights are on average of equal value, apart from the exception that the advantage of the bishop pair is worth about half a pawn (i.e., bishops aren't better unless you have two of them and your opponent doesn't)?

I, like most players, feel that the bishop is stronger in more situations even when not having the advantage of the bishop pair, so I don't know what to make of Kaufman's findings.