The switch is a pattern that uses a misdirection cut. The ball carrier runs in one direction, the receiver cuts back against that direction, and the defense ends up tracking the wrong shoulder.
The mechanics are precise. Carrier A runs across the field at an angle — say, drifting left. Receiver B starts on A's outside, but as A approaches the pass, B cuts hard back the other way. A passes to B as their paths cross. B is now running in the opposite direction, into space the defense has just vacated chasing A.
The switch works because of defensive momentum. As A drifts left, every defender's body and weight commits to the left. When B cuts back right with the ball, the defenders are out of position — they're moving the wrong way and have to brake, turn, and restart. That moment of reset is the gap.
Where it sits in a set: usually touches 3, 4, or 5, when the defense has committed to a direction across the previous touches. Less effective on the first touch when defenders haven't committed to anything yet.
The most common failure modes are forward passes (very common — B is cutting across A's running line, and the timing of the pass has to respect that B is at or behind A at the moment of release), B cutting too early so the defense has time to read the switch, A not selling the original direction strongly enough so no defender commits, and B running flat instead of cutting at a hard angle.