In amateur 5v5 the pick-and-roll murders defences not because the offence is fancy, but because nobody decides who guards what. Three coverages handle every scenario. Pick one as a team, call it before every possession.
Coverage 1: Drop
The big sags into the paint, lets the ball-handler take the mid-range pull-up. Use this when your big is slow + your guard fights over the screen. The trade is clear: you concede the long two, you protect the rim and the roller. Most amateur teams should default to drop.
Coverage 2: Hedge and recover
The big steps out hard at the ball-handler for one or two dribbles, then sprints back to the roller. Use this when the ball-handler is a known shooter you can't let pull up. Hard rule: the on-ball defender MUST get back on time, otherwise it's a 5-on-4 the moment the big recovers.
Coverage 3: Switch
Big and guard simply swap men. Use only when both defenders are similar size + foot speed, otherwise you give up either a post mismatch (small on big in the paint) or a perimeter mismatch (big on small at the arc).
The talking is the whole defence
The on-ball defender must call the coverage out loud before the screen lands. "Drop!" or "Hedge!" or "Switch!" Loud, every time. Without the call, you'll get two defenders on the ball-handler and a free roll to the rim.
Drill it in 10 minutes
5v5 half-court, every possession starts with a pick-and-roll. Defence calls coverage before the screen. Reset, repeat. Two sessions and your team gives up half the points.
Find a 5v5 game and try this. The improvement shows in one game.