Palming the basketball, also known as carrying, is a violation that results in a turnover when called on a ball handler. A palming violation should not be confused with "palming the ball," which is a technique that refers to gripping the ball with one hand.
A player has committed a palming violation if he/she places his/her hand under the ball while dribbling and moves to another spot on the court or stops his/her dribbling motion briefly before continuing again. Because a good crossover is often quick and low to the ground, a player might accidentally palm the ball when performing the move. This is because palming the ball makes it easier to control, even when done unintentionally.
Palming the ball is illegal because it gives the ball handler an unfair advantage over the defender. If the ball handler can pick up the ball and and easily make the defender think he/she is going to stop dribbling, only to put the ball back down on the floor, then it would be much easier for the ball handler to shift the defender off balance and get to the basket.
Sometimes, a player is thought to carry the ball if he/she loses control of the ball, leading to a particularly high dribble. However, as long as the dribbler's hand stays on top of the ball, it is not a palming violation.
In earlier eras of the game, players could only dribble with their hands on the top of the ball. As time went on, though, players got away with bringing their hands further and further down on the side of the ball. The evolution of the modern legal dribble started with Archie Clark, who is credited with being one of the first users of a real crossover. Countless players have continued to use what was once considered to be a palming violation, such as Allen Iverson, but have continually gotten away with breaking the rules. These players have now essentially changed the rulebook.