333 stands for playing 3-on-3 and needing 3 stops. The 333 Drill has mostly a defensive focus, but you can also coach offense at the same time. This drill forces your players to defend at a high level over a period of time.
333 starts with three offensive players and three defensive players playing 3-on-3. The remaining players form three lines near half court waiting to get into the drill.
The goal is for the defensive team to get three clean stops. A clean stop is when the defense prevents the offense from scoring. A clean stop also means that the offensive team does not get an offensive rebound during the possession. If the offense shoots and misses, gets an offensive rebound, and then turns the ball over this would NOT be a clean stop for the defense because they gave up an offensive rebound.
The defensive team must get three clean stops before they are "out". After each possession a fresh group of three offensive players comes in to play against the three defenders. This makes the challenge even greater for the defense, as it forces them to play through fatigue while competing against fresh players.
Once the defensive group gets three clean stops, a new group of three defenders come in to attempt to get their three clean stops.
*Coaches can allow the offense to just play. But you can also have the defense defend ball screens, down screens, dribble handoffs, back cuts, flare screens, or any other specified movement by requiring the offense to execute these during their possession.
*Cap the number of defensive possessions a group of three defenders can have. For example, if you cap it at six possessions the defense has to get their three clean stops within six possessions. If they don't, the run.
*Require the offense to get a paint touch before they shoot. This keeps the offense in an attack mode and prevents them from settling for jump shots. A paint touch can come from a post entry pass, dribble penetration, or passing to a cutting player in the lane.