Bishop pair is powerful than knight pair

I think the bishop pair is devastating toward the end game. Two fianchettoed bishops can inflict misery on your opponent. 

Well it's a well known fact that two knights tend to not particularly work well together.

More powerful*

The GM's are right. However there can still be exceptions. If your bishops are blocked in by its own pawns they are useless compared to the knight.

Generally speaking though, the bishop pair is more powerful.

People that know how to use their knights really well are dangerous opponents still. And it is possible to checkmate with 2 knights in the right positions. Plus they are tricky, some of the best forks, and most beautiful games involve excellent knight play, never underestimate them. Definitely learn to use them properly, they are a great weapon.

I had to add this, a single knight can give checkmate as well, in the right positions, and circumstances, the TT has loads of examples of smothered mates. Lets see if the bishop pair can do that, lol.

The bishop pair can even give a knight and rook a real fight if used effectively. With regard to the question of 2xN vs. 2xB it seems as though the less congested the board is, and most notably as the game heads into or towards the endgame, the bishop pair are likely to prove much more effective. Should you find yourself in a very blocked game, however, (see, for example, the classic Johner vs. Nimzowitsch game)*, the two knights may well be more useful.

* You can find this game on YouTube, in My System and in the Mammoth Book of Best Games edited by Nunn et al. not to mention many other books, websites and so forth.

Actually, the bishop pair is not a strength, but rather the lack of a bishop pair is a weakness. Look at it like this, the knights are completely interchangable, they can cover the exact same squares, whereas the two bishops are actually the only duplicate pieces that are opposites, they cannot defend eachother. Therefore, the lack of the dark squared bishop for example will cause a permanent weakened dark squares. If you have the bishop pair, you do not have any permanent weaknesses.

Very good point Nino. I've had numerous games where the knights out performed the bishops. From both sides of the coin, sometimes on the winning side, and sometimes on the losing side. I've played many where the bishops were the best as well.

Sometimes you don't get a chance to choose which you would like either. Generally knights are better in the end game if the opponents pawns aren't on both sides of the board, the bishops can go from one side of the board to another in a single move, the knight can't do that. This can mean a single knight or bishop as well.

The thing about bishops also is the queening square color of a potential passed pawn, you can usually notice this in the middle game, If your bishop doesn't match that square color, you may want to get rid of that pawn asap, or make sure your king can get to it. You can also do this with a knight (make sure its in a good position to be able to stop it.). These are things you look for in the middle game, before you simplify the position.