I wouldn't take four points for a rook unless:
- It improves my positional advantage more than the lost material.
- I am up in material and need to take out a threat. (ex. pawn getting close to promotion with bishop defending it.)
- My rook is trapped and I would lose it entirely if I don't take the four points for it.
Usually you would want to be the one giving up four points for one of your opponent rooks.
IS A ROOK WORTH 5 POINTS: A Bishop gets 3. So would 4 points for a ROOK be enough???