I think it depends on what you prefer playing with. I find players tend to over look moves with knights rather than bishops knights are also good at getting in awkward spots for the opponent, so i usually prefer them. They tend not to be quite as strong as bishops in most end game scenarios though.
I often try to swap so the opponent has only one bishop, as i think having only one colour makes them weaker.
This depends mostly on play style and position.
Most books give knights and bishops the same piece value. So this is OK, but that does not mean it is good.
Some people use their knights more than bishops and other are the other way around. So you may be helping out their play style.
Also, for your comment that bishops only move on their color may be restricting, but you may want to consider is this: 2 Bishops and a king can deliver checkmate, whereas 2 knights and a king cannot.
Generally you want to trade inactive pieces for active pieces.
There is no set *rule* for exchanging pieces. Sometimes even trading your bishop for their queen could be a bad move, because they might deliver checkmate.
So you have to look at the position more than anything else. Decide what is more deadly on a per game basis.
If position is open bishops are usually stronger than knights, if closed knights are usually better. I think in modern chess bishops are more valuable than knights. Some players value bishops as 3.5 points against 3 points for a knight. Also, bishop pair is deadly weapon in open/semi open positions (bishop pair, when 2 bishops placed next to each other, almost doubles the power of bishops). In the endgame bishops are usually stronger too (especially bishop vs. knight endgame open/semi open position).
Do not always trade your bishops, they are very good long range, quick pieces.
hope that helps
I have heard things such as "two bishops are better than two knights, but one knight is better than one bishop" but like every else was saying, it depends on the situation. I was surprised to hear that many who have commented prefer bishops. I would gladly trade my bishop for an opponents knight just because the knight can be so tricky and evasive, I'd rather play with them than against them.
My name says all : The Noob. . . . .
I am trying to ask . . . Is exchanging all bishops for knights OK?
I was thinking. . . . Bishop only goes black or white. . . so if I take out 1 of my opponents Bishop with exchange of a knight. . . will that do me any good??