[Luzion]

This isnt really a good question to post in this section. Its better off you post it in the PLNL forums because you are asking some very beginner-ish questions on NL. But anyway, NL is all about implied odds. The way you "calculate" it is simply reads you have on someone combined with common sense.

The question you should be asking yourself is, can you make up for the money lost by "chasing," if you hit your draw? In NL you have to consider your implied odds, which is how large your stack is compared to your opponents.

If you and your opponent have large stacks, obviously you can play more hands preflop and draw more liberally for the chance to take your opponents large stack. If you are your opponents have smaller stacks, you cant play as liberally preflop and you have to draw with better odds. You must also factor in your opponents tendency to be willing to put in lots of money into the pot once you hit that draw...