See also
Some useful mathematical facts:
Holdem:
If you flop a flush or a straight draw, with no other ways of winning, you are approximately a 2 to 1 underdog.
If you have a small pair and need to make trips to win, you will not have sufficient pot odds in limit hold'em to take a card oil on the turn.
If you have 13 outs on the flop, you will typically be a slight underdog.
If you have 14 outs on the flop, you will typically be a slight favorite.
A big pocket pair against a small pocket pair is slightly more than a 4 to 1 favorite to win the hand.