Often times, players will trade their rook for the opponent's knight and bishop.
This seems to have a slight advantage materialistically as a rook is worth 5 and a knight and bishop are worth 6 total. But from a strategic view, this seems quite unnecessary as it is very hard to coordinate the knight and bishop together (it takes 33+ moves to checkmate by themselves versus a King) let alone deal with a rook at the same time.
Midgame though, they might have an advantage as with all (or most) of the pieces all over the board, the rook may have trouble navigating through the board. The bishop-knight pair though should be sound since the knight should just jump all over the board. Endgame though, I just don't see how a knight and bishop can overpower a rook.
So my question is, when is a bishop-knight pair generally stronger than a rook?