“Thumb Down/Up”

Term: Thumb Down/Up

Definition: A half-court set in which a ball-screener receives a down screen from another offensive player before initiating a pick-and-roll with the ball-handler.

Synonyms: Rub

Explanation: The notion of a good screener usually refers to an offensive player’s ability to create hard contact. Great screeners, the thinking goes, dish out punishment on every ball-screen or pindown. But this is an incomplete, and somewhat inaccurate, characterization of the screening process. On any given screen, contact is not necessarily a requirement — sometimes it’s more beneficial for the offensive player to slip the screen or roll to the basket before connecting with a defender.

What is less negotiable is the separation a screener creates with his man before contact. This is why many coaches urge their bigs to sprint into ball-screens. If they can literally run away from their man before the pick-and-roll begins, they can screen freely without getting bumped off their spot by their defender. Furthermore, a ball-screener who creates adequate separation ideally can prevent defenses from utilizing an ice, weak or aggressive pick-and-roll defense. This is because the separation created by a hard sprint forces defensive bigs to organize, line up and call out a coverage within a much tighter time frame. Any type of miscommunication or hesitation can give the offense a significant advantage. To avoid these errors, defenses will rely on a single, conservative pick-and-roll coverage: the deep drop.

Although many defenses actively opt for this type of coverage due to personnel strengths and weaknesses, many offenses prefer to face it. The runway provided by the distance between the screener and his defender gives ball-handlers room to attack athletically, and for great shooters, it can lead to clean, pull-up three-pointers.

One of the ways offenses aim to mold ball-screen defense in this way is through a pick-and-roll series known as “Thumb,” with variations of “Thumb Up” (Up = pop) and “Thumb Down” (Down = roll). The action in its most regular sense is simple: One big screens down on another, and the low big sprints out of the hole into a ball-screen. The hope is that, in the process of navigating this extra screen before the pick-and-roll, the ball-screener’s defender gets caught up in the chaos. In a perfect world, this delay leads to some type of defensive breakdown. More often than not, however, it leads to a drop of some kind and room for the offense to operate.

(Note: Not at all teams call this action “Thumb,” since NBA terminology, especially when it comes naming half-court sets, can vary.)

Here’s an example of “Thumb Down 4” — the number at the end indicates which position sets the ball-screen — that illustrates these concepts. As Dwight Buycks of the Detroit Pistons awaits a ball-screen, teammate Eric Moreland sets a big-on-big down screen for Blake Griffin.

With the smaller Justise Winslow guarding Griffin, Detroit hopes to target him in a pick-and-roll situation. But simply setting a ball-screen wouldn’t quite do the job: Winslow could show or pressure the ball-handler in some other way that would disintegrate the seemingly positive offensive mismatch.

Going to a Thumb action — and knowing Miami doesn’t want to switch Winslow onto a further mismatch in Moreland — means Winslow will have to chase Griffin to the ball-screen through bodies. And in order to execute an aggressive pick-and-roll coverage, Winslow must be at or near the point of the screen as it occurs. The Thumb action, however, prevents this. By the time Winslow gets through the Moreland screen, look where he is:

Because he knows he’s going to be late — and doesn’t want to get caught moving up the floor while Buycks starts heading downhill — Winslow is forced to stop in his tracks and audible to a deep drop.

This is the exact situation Detroit hopes for, because Winslow, as a 3/undersized 4, is not accustomed or built for this coverage. When Buycks comes off the pick and throws an easy pocket pass through the window created by the deep drop, Winslow is no match for the bigger Blake Griffin rumbling to the rim.

Although it might not look like much, an intelligently applied Thumb action can have very positive consequences for the offense.

Thumb Against Switches

To prevent the deep drop caused by the screener’s defender lagging behind, many teams will switch the big-on-big screen in a Thumb action. Given that it invovles two like-sized players, defenses can survive this switch with limited consequences.

Offenses typically counter this defensive response by changing up who sets the initial screen. Instead of using a big-on-big screen — the effectiveness of which could be eliminated by a defensive switch — offenses will stick a wing into the action. When the wing gets the 5, a defensive switch is not only less likely, but it is also even beneficial to the offense should it occur. If the defense guards the action traditionally — with the 5 fighting through to get into proper defensive ball-screen position — the offense has accomplished its goal.

(Note: A sample playcall for this type of action might be “Thumb Down 25,” indicating positionally who screens for whom. Some teams however, use the numbers to indicate the ball-handler and the screener, meaning “Thumb Down 25” ends with a 2–5 ball-screen.)

Look at how Rudy Gobert of the Utah Jazz changes his path up to the ball-screen here as the Portland Trail Blazers run what could be termed a Thumb Down 35 set. Although Donovan Mitchell, the on-ball defender, switches his stance into an ice, Gobert is approaching the ball-screen from the wrong side. His attempt to avoid the initial screen from Mo Harkless causes this distortion.

Although Utah prefers Gobert to drop deep anyway, his imprecise route to the ball-screen forces him to move laterally across the floor. C.J. McCollum, the ball-handler, takes advantage of this by engaging Gobert and quickly crossing him over back toward the direction from which he came. This allows McCollum to create enough room for a pull-up.

In the previous example, Thumb Down 4 worked because Justise Winslow got stuck in a guarding position to which he is not accustomed. Here, Thumb Down 35 works because Gobert is unable to properly line up his defense.

Thumb As An Attachment

Not all Thumb actions result in middle ball-screens, nor do they always live on their own. Given its simplicity, many teams attach Thumb to other sets as a way to create further separation. Here’s an example of that, with the Golden State Warriors entering a “Weak”-like ball-swing action before Omri Casspi screens for teammate David West, who heads into a ball-screen with Patrick McCaw.

The Thumb series is a great blend of natural creativity and designed action. When targeting the right matchup or opponent, it can put your two best players in not just a ball-screen, but an advantage ball-screen. For some of the league’s best players, even the slightest initial edge is enough to pick apart any defense.

Film Study: “Thumb Down/Thumb Up”

Below is a video compilation of Thumb actions from NBA games. Take note of how the contact on the initial down screen impacts the defensive big, and in particular whether his altered route toward the ball-screen coverage hurts his chance to defend the play.