When to Fold and When to Raise

We have said, up to this point, that the two main defenses against the semi-bluff are simply giving up and folding, or raising. (In all cases we are assuming the pot is relatively small.) The question now is when to do the one and when to do the other. That is, when do you fold, and when do you raise?
Obviously when you have a very poor hand, you fold. When you have a big hand, you raise unless it's so big you want to slowplay and trap your opponent later. The difficult decisions occur when you have a medium-value hand. There are three principle criteria you should use in deciding whether to raise or fold:
1. The chances your opponent is bluffing or semi-bluffing.
2. The chances that opponent will outdraw you if he is betting with the worst hand.
3. The chances you will outdraw that opponent if he is betting the best hand.
The more you believe your opponent is bluffing or semi-bluffing, and the greater your chances of outdrawing him if he does have a legitimate hand, the more you will tend to raise. On the other hand, the smaller these chances are and the greater the chances your opponent will outdraw you if he is betting the worst hand, the more you would tend to fold. Recall an example earlier in this chapter. The chances that your opponent had the best hand were quite high (48 percent); the chances of your outdrawing him were so low as to be virtually nonexistent. At the same time the chances of your opponent outdrawing you were very high (you were only a 6-to-5 favorite if he didn't already have you beat). It was the combination of all these chances that dictated a fold.