Bishop or Knight: Which is more valuable?

Their values change, depending on the needs of the position.

In an open position, bishops are usually more valuable than knights.

In a closed position, knights are usually more valuable than bishops.

Both bishops and pawns can be dominated or boxed in by pawns or other pieces, so sometimes, if immobilized, their value drops down to that of a lowly pawn, or even lower.

In some positions, even, a bishop or a knight can be worth more than the queen.

It depends on a lot of factors.

The trick is to learn how to recognize the ever-changing value of your pieces ... and it's not an easy trick to learn, at all ...

I'll add that some years ago Kauffman a la Rybka calculated that the bishop pair gives a small bonus... meaning the first bishop you lose was worth more than the 2nd. Individual B vs N was calculated as equal on average (simply depends on the position).

A pair of Bishops can be brutally effective in all but the most closed positions. When teamed up, they are considerably stronger than Knights.

Curiously, a Queen + a Knight is stronger than a Queen + a Bishop... possibly because they interfere with each other less.

two bishops are always complementary.

two knights often fight over squares & outposts.

Two bishops can never combine on the same square though.

But other than being complementary, typically the player with the two bishops is the one who decides when and where to transition to a B vs N, (or B vs B) so that's one way to compensate.

One can pressure a square, the other can pressure an enemy Knight that is defending the square.

... so in that sense, they can both coordinate pressure on a specific square.

I guess that's common enough to be a good counter example, ok, good point.

bishops can corral knights & are able to maintain control over the same squares when they move... they can also operate in two sectors simultaneously & are better than knights at stopping distant passed pawns.

http://bitly.ws/nF5Y.

It's probably because the knight covers more unique directions than bishops.

Bishops can cover more squares, but only up to four diagonals at a time. 

Knights cover up to eight directions at a time (north-north-west, north-east-east and so on).

If we have a knight on e5, it covers squares g6 and f7 to support a queen on those squares. I think this ability is what makes knights and queens complementary to each other.

If the two bishops reside on the same colour square, it's possible.

(Though we are not going to see this situation that often in practical play)

queen & knight complement each other because between them they cover every possible way a chess piece can move.  🙂

I suppose even in practical play, there are two light square bishops (one for white and one for black). They can "combine" on a square, heh.

But yeah, that's not what I meant.

both are important

a bishop is good at assisting but knights are good for close range

This is quite a big discussion among chess player. There is a good summary of the topic on chessily: https://chessily.com/questions/bishop-or-knight-which-is-better/

depends on position

Lol

Bishop looks strong in the midgame, knight is in the endgame, but the most powerful is when you have both bishops.