You never know an exact value and can't find them anywhere, VIP doesn't show you anything with hiddens either. Basically for those who have played the game a bunch, it's been a testing process and it's mostly using the tale of the tape, confidence drop after loss, and reading many fights. If you see a guy get cut in every fight, you know he has a low cut hidden. If his confidence drops to 0 after a loss and he took a couple punches and stopped fighting you know he has low confidence. etc. If tale of the tape shows granite/good chin he's tougher to knockout and so on and so forth.