The pick-and-roll is a reliable action with endless wrinkles, but unless Miami can start taking advantage of the gravity it produces — with more movement and passing — they are going to be more predictable than desired.

As halftime approached, the bottom-dwelling Chicago Bulls are giving the Miami Heat a run for their money. Goran Dragic and company are having trouble generating good shots, and Miami’s double-digit lead dwindles to 2 by half.

Rewind. Miami’s bench unit is on the floor at the beginning of the second quarter. Featuring Kelly Olynyk and Justise Winslow in the frontcourt, it’s without Miami’s most notable players — no Dion Waiters, Goran Dragic, or Hassan Whiteside. And that second unit created open shot after open shot.

Miami ran its offense through Olynyk — a simple read and react pick-and-roll. The Heat enjoyed offensive fluidity; the ball was popping, as NBA coaches might say.

Some NBA coaches have been recalcitrant regarding switching on defense — having players switch defenders when it is convenient, to avoid defensive collapse — because it makes their players passive. They want their players fighting around and through screens, playing dogged defense. It keeps them attentive. The same ideology might be said for the offense.

The pick-and-roll is the NBA’s darling. The two-player duet can often result in an open shot for any of the five players involved, even if they’re standing on the perimeter, hands jittering, waiting for a pass. Think the Houston Rockets 2 years ago: James Harden dribbling the ball, waiting for a screen, then whipping a pass to one of his triggermen on the perimeter.

Though the action warps the gravity of an NBA court, it can also become stagnated and guardable, especially when it’s predictable:

Dragic is coming downhill off the pick; Whiteside is a non-shooter for the most part, and Winslow is camping out near the lane. All the Bulls’ defense has done to nullify this Dragic-Whiteside toilet clog is guard the perimeter and pack the paint.

There was no rescreening, the Bulls weren’t worried about Dragic dumping the ball to Whiteside and him setting up a teammate. They knew what to expect.

Even on a more active pick-and-roll, the Bulls are able to key in on Miami’s shooters and strangle the possession:

Though the pick-and-roll is one of the NBA’s preeminent actions, the best teams don’t utilize it as much as you’d think. Both the Golden State Warriors and San Antonio Spurs are in the bottom-five in pick-and-roll frequency, with the Warriors sitting dead last. Pick-and-rolls take up less than 10-percent of the Warrior’s offense, according to Synergy.

In an ESPN.com report, Warriors coach Steve Kerr said, “[...] there's a makeup in every player who's ever played," Kerr says, "that if you get to touch the ball and you get to be a part of the action -- whether it's as an assist man, ball mover, shooter, dribbler -- the more people who are involved in the offense, the more powerful it becomes.”

There is something to be said about the fluidity of constant movement, something Miami’s pick-and-rolls can stymie.

Miami’s most-played lineup — featuring two lead ball-handlers in Waiters and Dragic, James Johnson, Josh Richardson and Bam Adebayo — is minus 21.8 points in 44 minutes. Meanwhile, Miami’s second unit — Kelly Olynyk, Justise Winslow, Richardson, Tyler Johnson, and Wayne Ellington — which doesn’t feature a true point guard is plus-14.9 in 36 minutes. Those numbers translate into plays like this:

With the pick-and-roll drive cut off by Robin Lopez, Kelly Olynyk is able to get himself open for a pocket pass, collapse the defense and find Richardson for a decent look at a corner three. Constant motion and ball movement were what got Miami that open shot. Kelly Olynyk was able to make the defense pay for collapsing on him. That possession could’ve looked very different, though:

Take that Dragic-Whiteside pick-and-roll. The defense got off easy; all they did was pack the paint. Tyler Johnson was open on the wing, but Whiteside didn’t look for him. These are the types of pick-and-rolls that make Miami guardable, even when they stretch the floor with a sharpshooter.

The pick-and-roll is a reliable action with endless wrinkles, but unless Miami can start taking advantage of the gravity it produces — with more movement and passing — they are going to be more predictable than desired.