Isolation, or iso, is an offensive tactic that clears one side of the floor so a scorer can attack a single defender one-on-one.
Isolation is basketball reduced to a duel. The offence spreads its four other players to the far corners of the floor, removing help defenders, and the ball handler attacks one defender with dribble moves, strength, and a step back jumper, while the shot clock drains. It is the least systematic tactic and, in the hands of a great scorer, one of the most reliable, because no scheme can help without leaving a shooter.
Its reputation swings by era. The 1990s and 2000s leaned on isolation for their star driven offences, the analytics era criticized it as inefficient and stagnant, and the playoffs rehabilitated it, since late in a close Finals game an isolation bucket against a set defence is often the best available shot. James Harden's step back era made him its modern emblem, a system of one.
Isolation defence is its own specialty: the defender who needs no help, who can be left on an island, is among the most valuable players in the sport. Glossary neighbours double team and help defence exist precisely because isolation exists, and quiz questions about late clock strategy are usually asking which duel a coach chose to trust.
In use"With the shot clock dying, they spread the floor and let their scorer work in isolation."