A tweener in basketball is a term, sometimes used derisively, for a player who is able to play two positions, but is not ideally suited to play either position exclusively, so he/she is said to be in between. A tweener has a set of skills that do not match the traditional position of his physical stature. NBA.com's definition of "tweener" is as follows: A player who is ideally suited to play two positions is sometimes referred to as a swingman, although that term is more commonly reserved specifically for those who are suited to play small forward and shooting guard.
This tweener has the skills of either a center or a power forward, but is usually stronger than traditional power forwards and quicker and often more skilled than traditional centers, and is generically called a "big" or "big man" in American basketball, where the distinction between power forwards and centers has become increasingly blurred. Many times C/PF tweeners are used to create match-up problems. Usually, this tweener will have a power forward’s inside shooting abilities and a center’s height or blocking abilities. Amar'e Stoudemire is an example of a tweener. Other prominent NBA players who switch between power forward and center are Dirk Nowitzki, Tim Duncan, Kevin Garnett, Pau Gasol, Chris Bosh, Kevin Love, LaMarcus Aldridge, David Lee, and Anthony Davis, among others. A good example of such a Euroleague player is Mike Batiste.
Shooting guard / small forward (swingman or guard-forward)
This tweener is not suited to exclusively play either at shooting guard or small forward. For example, he may be too short to play small forward, but lacks a guard's jumper or ball-handling skills to play the two-man. To counter this, this tweener could play as a swingman. Some swingmen have been known to play both the small forward and shooting guard position effectively, having the size and strength to play the small forward position, as well as the outside jump shot and quickness to play the shooting guard position, such as Kobe Bryant, Jimmy Butler or Michael Jordan. These tweeners are known to cause match up problems, and have proven to be very difficult to guard. Such NBA players are Kobe Bryant, Jimmy Butler, Josh Howard, Andre Iguodala, Jason Richardson, Manu Ginóbili, Paul Pierce, Vince Carter, Shane Battier, Jaylen Brown, and Tracy McGrady. One WNBA example is Elena Delle Donne, who has been listed as a guard and forward throughout her WNBA career despite being similar in size to most of the league's centers. A good such example for a Euroleague player is Ramūnas Šiškauskas.
Point guard / shooting guard (combo guard or ball handler)
Some NBA players, most notably players like Luka Doncic, Boris Diaw, Larry Bird, Scottie Pippen, Grant Hill, Lamar Odom, Magic Johnson, Draymond Green, James Johnson, Blake Griffin, LeBron James, Nicolas Batum, Gordon Hayward, Ben Simmons, Pascal Siakam, and Giannis Antetokounmpo, possess the size, strength and rebounding skills to play a forward position, yet they also have the passing and ball-handling skills, along with the "basketball IQ", to perform at the point guard position. These players often cause match-up problems on both ends of the court, because while the tall, strong point forward can dominate a traditional point guard on the offensive end of the court, he is sometimes at a disadvantage on the defensive end against smaller, quicker guards.