It's worth very little in my opinion.
There are certain positions where bishops are just better, but it's a fallacy to think that having two bishops is an advantage per se.
Also, if you have the bishop pair your opponent most of the times has a remaining bishop, and in most cases it's not too hard from to trade a pair. BB is a fleeting advantage imo.
Depending on the situation a bishop pair is more deadly than a knight pair, right? And vice versa. I've devastated my opponent and been devastated by opponents with both types of pairs. They both can hold each other at bay. But it's always interesting to play with a pair of bishops vs. a pair of knights. And sometimes the difference as to which prevails or is stronger is just one tempo
I really like using the bishop pair in my games. on an open board, they be an unstoppable killing force. However, in a closed game with many pawns locked togeather (like a stone wall for example) the knight tends to be quite a bit stronger. for example, pawns on d4 and f4 for white, and d5 and f5 for black. A white knight on e5 will be better than either bishop. but now, consider a center without a single pawn on it, and a 0-0 black king. now put those bishops on c2 and c1. looking good eh? In conclusion, depending on the openings you play, the bishop pair is more or less important.
Conventional wisdom doesn't always hold up. For example this pair of bishops is definitely a lost position:
They have great practical value. You can sac a pawn or two to open the position, so with the bishops you don't have to keep the material balance at any cost (the pawn sac for two bishops has become a standard in modern opening theory). Likewise you don't have to avoid simplifications, because the bishops tend to become stronger with the reduction of material.
Depending on the situation a bishop pair is more deadly than a knight pair, right? And vice versa. I've devastated my opponent and been devastated by opponents with both types of pairs. They both can hold each other at bay. But it's always interesting to play with a pair of bishops vs. a pair of knights. And sometimes the difference as to which prevails or is stronger is just one tempo
Bishop pair is generally better than knight pair (and read my post above, I'm not a fan of the bishop pair). The reason is that the bishops have a better synergy
In fact, the weakness of the knight is that they are short range. This weakness does not go away if you have two. While the bishops compensate each other's weakness.
The problem is, it's very rare for me to see a situation of BB vs NN.
95% of the times, it's BB vs BN.
Open to general discussion.
Not just talking point value etc.