Quote Originally Posted by pat1002
in live poker there is also betting patterns but there is small tells that certain people do that you have to pick up on. I suggest reading mike caro's book of poker tells.
I don't think this is a major part of anyone's game. Maybe you find something against one specific player, or maybe you get a very vague guess about the strength of a hand.

Betting patterns is the key. What is this guy's range when he raises? Why did he check when he usually bets? Why did he bet twice the pot? Why did he bet half the pot?

They're all clues, and after you watch enough hands played out, you can put the pieces together some or most of the time. There's no way that I know of besides playing (or watching) lots of hands to develop this skill.