The slam dunk is a simple maneuver in basketball, defined as the delivery of the ball through the rim of the basket, or cylinder, by one hand or by two. Dunking is a relatively easy shot for the tall player, given that the 10-ft-high (3 m) basketball rim can be touched by the many National Basketball Association (NBA) players standing flat footed beneath it. The ability to dunk the ball is more often a function of leaping ability; many dunks in competitive play are made by players shorter than 6 ft 2 in (1.8 m). From a physiological perspective, the presence of a larger number of fast twitch fibers in the calf and thigh muscles, the muscle construction that is capable of speedy reactions, is an important factor in the leaping ability of a player.
The basketball slam dunk: it is only worth two points, the same value as a medium-range jumper or a simple lay up. A consistent three-point shooter will have a greater value to a basketball team than a flamboyant slam dunker. The dunk is so often an exclamation point, but not the story: a slam dunk is rarely a tactic that will win a basketball game.
However, in many respects the slam dunk has come to represent basketball proficiency in the public consciousness. Lisa Leslie, a 6 ft 5 in (1.9 m) Women's National Basketball Association (WNBA) player, slam dunked the ball to much acclaim. Sports television highlight packages accentuate flashy dunks, as do basketball advertising and basketball shoe promotional packages. Many players acquired an identity through their proficiency as dunkers, even when they possessed other, more sublime playing skills. Men such as Julius "Dr. J" Erving, Darryl "Chocolate Thunder" Dawkins, a notorious backboard breaker in the early 1980s, Dominique Wilkins, "The Human Highlight Film," and Michael "Air" Jordan are notable examples. It is these players who elevated the dunk to an exciting example of body control, an emphatic statement that transcends the two-point value the shot is awarded on the score sheet.
In specific game situations, the slam dunk has tactical advantages. The first is the certainty that the delivery of the ball directly into the basket brings to an offensive play. Players are taught that on an offensive rebound, they must be "strong to the rim," meaning they are not to risk handling the ball for any longer than is necessary. The securing of an offensive rebound, a quick step to the basket and the dunk achieves this end, generates a possible additional benefit if the offensive rebounder is fouled, which creates a free throw opportunity, as well as the two-point basket.
The second specific tactic involving the slam dunk is the use of the lob, or "ally oop," pass, where the ball handler lobs the ball to a point above the basket. The lob is taken by a team mate, who leaps to take the pass and then to slam the ball through the basket. Properly executed, the ally oop is very difficult to defend.