The stretch four is a fairly recent innovation in the NBA (with an "explosion"[1] of players coming through since the 1999–2000 season),[2] but is still becoming increasingly common in today's game, as many NBA coaches now use the "small-ball" line-up/tactical play.
[4] A stretch four is a player that is of power forward size, but has superior shooting skills (especially three-point field goals), spending more of their time away from the basket.
[5] While using these skills on offense, the player retains the ability to defend the opposing power forward.
The ability to score a high percentage of catch-and-shoot three-point shots from distance (the distinct feature of a stretch four[6]) causes defensive problems for the other team, as it pulls the opposing power forward defender out of the low post area, opening up driving lanes for teammates to exploit (these can be running lanes or passing lanes).
[7] Unlike some traditional, plodding power forwards, stretch fours must also be able to defend counterparts who can shoot from outside.