The main difference between a 3 piece and a 2 piece golf ball is in the short game. The extra layer of the 3 piece golf ball allows the ball to compress and create spin characteristics that are not possible with a two piece ball. 2 piece balls are almost always made of surlyn which is a harder material then urethane which is common in the multi-layer golf balls. The urethane ball will provide more spin and also a softer feel then the surlyn ball.