Morton's Theorem on Poker
Morton's theorem is similar to The Fundamental Theorem of Poker by Sklansky which states that "If your opponent makes a mistake, you profit." This theory is for the heads-up play while Morton's theory is more appropriate in multi-way pots with schools of fish and with calling stations.
Morton's theory states that, "If there is a multi-way pot, the individual errors of the opponents are reduced by the larger pot size." This means that the hands with the greater draw potential have an increased value as they will make the draw more frequently and in the multi-way pots the drawing hands typically win. The value of hands with the nut-draw potential is increased while the value of pairs is considerably reduced. Most of the time, the unlikely straight, full houses and flushes will take down the pot crushing wired large over-pairs.
The question is how will this affect your play? You will put a lot less value on over-pairs in a multi-way pot. More or less the straight or flush draws that complete the river will win the money crushing the big pair starting hands. The hands with solid draw potential, you will limp in for the flop and if you hit two of the three needed for you hand, multi-way pot odds typically make calling a no-brainer.
What will be the most excellent play with large over pairs? Your keen observation on how your opponents play in a given situation will help you. In a very close game you must try to chase the draws out of the pot and win right away. You can end up in the heads up match and then you can play the flop insistently to end the hand and win the money.
In a loose game, you can tend to try to play the hands less aggressively. When your pair flops into trips and you do not see many draws on the turn you can play aggressively but with the draws on the board and there are more than three people on the pot your chances of winning will decrease.
This is the basis of Morton's Theorem. Every player has the opportunity to crack your hand but if the players in the multi-way are put together they will have more than 50/50 of besting the large pair.
This is the classic case of the sum of a group of players being greater than the single player.