In “switch” the two defenders swap responsibility for guarding the offensive players. This is most commonly used where the two offensive players are similar, although particularly late in the “shot clock” a team may switch all screens. In switching, the defender initially guarding the screener must move aggressively to deny the cutter the ball. The other defender must similarly move quickly to establish a position to defend the screener.

Defending Middle Pick & Roll Switch
Defend Side Pick & Roll Switch
Defend On Ball Screen Switch