Useful loophole or distasteful trickery?

349 instances of 3-shot fouls over just the past two seasons, according to data provided by the NBA.

So what happened? In short, players and teams found a loophole in the rules, a way to game the system, and have begun exploiting it as much as possible.

Harden and fellow guard Lou Williams have become synonymous with the play, excelling at it more than virtually anyone else.

It’s a simple concept: Initiate contact, as opposed to letting a defender fly by. But it has become virtually impossible for defenders to stop.

Their aggression helps players such as Boston Celtics star Isaiah Thomas notice when defenders are chasing them hard over screens on the perimeter. Thomas can then take advantage — baiting a foul call the defender has virtually no way of avoiding.

“When I’m coming off screens and they’re trailing me kind of fast, I watch them and see when they can’t stop on a dime like I can,” Thomas said. “It’s just something I picked up.”

Against the Rockets, the Spurs encountered a 3-shot foul situation that begged for a solution. In its five-game series against the Oklahoma City Thunder earlier in the playoffs, Houston racked up 17 such fouls, and garnered four more — including Harden’s ridiculous half-court heave in Game 2 — during the opening two games of its series against San Antonio. Those four were the only three-shot calls Houston earned during the series. What did San Antonio do? Mills said San Antonio had a clear plan: Give Houston’s offensive players as few opportunities as possible to bait defenders into foul calls. The Spurs even had a name for it — keeping their hands out of the “strike zone.”

“It’s all about getting your hands up,” Mills said, “and keeping them out of the strike zone, as we call it.”

Not surprisingly, the dramatic increase in three-shot fouls has led to calls for the NBA to do something.

“Well, obviously we’re aware of it,” said Kiki Vandeweghe, the NBA’s executive vice president of basketball operations. “It’s a difficult play to officiate. It really is.”

Given the amount of attention that’s been paid to these plays over the course of this season and the playoffs, it seems likely that some sort of change will be coming.

Even Thomas, who has become one of the most successful players in the league at drawing such fouls, believes a tweak will be made.

“They’re going to have to change that rule, probably,” Thomas said. “I mean, everybody is doing it.”