The game of college basketball is essentially the same as the pro game with a few exceptions. One of the most important distinctions between the pro and college game is in terms of the shot clock. The NBA and other professional leagues use a 25 second shot clock, in which a team must have the ball hit the rim or lose possession. However, college basketball employs a 40 second shot clock for each possession. In this way, college basketball allows a more patient offensive and defensive setup, with many teams making a number of passes on offense before taking their first shot. The 40 second shot clock allows college teams to create better opportunities through longer offensive sets and requires greater stamina in man and zone defenses.
Another timing difference between the pro and college game comes with the game clock. Professional basketball uses four 12 minute periods to divide up the game, while college basketball uses two 20 minute halves. The college basketball game clock stops every four minutes for a television time out, which gives teams five additional time outs to their usual array of full and twenty second timeouts. The difference in time is often attributed by rookie professional players as a reason why they hit a proverbial wall part way through their first professional season.
A final difference between the pro and college basketball game is in terms of legal defenses. While the NBA has opened up the option of zone defenses, previously illegal throughout league history, there are still restrictions on the type of defense played. However, college basketball features unfettered defensive formations, whether it is man or zone. Often, teams will be defined by the defense they play. For example, Temple University is renowned for its skilled zone defense while Texas Tech and Indiana University, both coached by Bobby Knight, have been known for their man-to-man defense. While both leagues share the three-second lane violation, the defensive schemes for both are quite different.