Definition: A technique in which a defender follows the path of an offensive player receiving an off-ball screen while physically preventing him from cutting backdoor.
Synonyms: Lock and Go
Explanation: The “lock and trail” is the favored defensive technique among most NBA coaches for guarding screens away from the ball. Because
pindowns and
staggers are so frequent in NBA offenses, the ability to guard these actions is of paramount importance.
Navigating off-ball screens is one of the most difficult jobs on defense due to its reactionary nature: Defenders never
really know where the offensive player is going. He could use either of multiple screens in both directions. He could start to use one then cut backdoor. He could cut, stop, then continue sprinting to the three-point line. He could cut backdoor, pivot, and fly off the screen. The possibilites are endless, and the defender has to mimick these movements without committing a foul.
The lock and trail is a defensive attempt to dictate to the offense. In short, it gives an offensive player looking to spring free off a pindown or stagger one option:
Use the screen.
By eliminating the offensive player’s choice, a defender can prepare his teammates for the subsequent action. Even though the lock-and-trail is technically the action of one defender, it’s use sets off a chain reaction of defensive movements to cover its weaknesses.
Most commonly, a lock and trail is used against strong shooters. When an offensive player coming off a stagger or pindown recognizes that a defender is about to trail his path, his natural inclincation is to curl to the rim. With the defender constantly trailing from behind, the offensive player will, at some point, find a path to the rim with his defender
not between himself and the basket.
So why would a defense encourage a curl for the easiest shot in basketball?
Two reasons: Firstly, it drives shooters off the three-point line. Would you rather Steph Curry dart out to the three-point line or try to finish around the rim? Even though you might be giving up a potentially easier look that’s closer to the basket, the lock and trail defense, in a properly executed scenario, stations a big in the path of the cutter. Instead of a layup at the rim, the shooter is attempting a mid-range two-pointer or a difficult finish against a rim-protector. And of the league’s elite shooters, most struggle finishing in the paint. 99% of coaches would prefer a J.J. Redikk floater at 10 feet to a J.J. Redikk catch-and-shoot three-pointer.
Well-coached teams will predetermine which players will be locked-and-trailed and rehearse the defense ad nauseum. Even though every NBA player knows how this defense works, even minor slipups in game action leads to a barrage of three-pointers.