How Texas' Ball Screen Defense Beat Baylor

Having lost four straight games and still needing wins to have a reasonable chance to make the NCAA tournament, things did not look good for Texas on Monday night. Baylor had led the game from almost the opening tip, and with a little more than six minutes remaining was sitting on a ten point lead. The end looked near.

During Texas' struggles this season, I have pointed out on several occasions how the team's biggest weakness seems to be its perimeter defense, and that the Longhorns have struggled in particular defending ball screens. It made Baylor a problematic match up, as Baylor's highly effective offense leans heavily on using the ball screen to break down the defense and create chances for the Bears many dangerous shooters.

But at this critical point in the season, Texas' ball screen defense transformed from a weakness to a strength. All it seemingly took was making a simple adjustment.

Texas started switching screens.

Why isn't switching ball screens more common?

Basketball as it is played in this day and age is heavily dominated by ball screens, with many top college offenses learning what the NBA guys have known for years -- the pick and roll is a great way to get a good shot with a minimal amount of messing around. It is a low risk, high reward play.

With so much emphasis on screening for the dribbler in the modern game, modern defenses have developed a diverse range of tactics to counter ball screens. Many of these concepts come from the NBA, where the cat and mouse game between offense and defense in the pick and roll is high art. These ideas have trickled down to the college game, following closely after the pick and roll invasion. This excellent article from SB Nation reviews ball screen defense at the NBA level.

There are a handful of ball screen defenses that show up more often than most in the college game. Perhaps the most common are:

• "Hard show" -- a tactic where the big man defending the screener steps out and attempts to alter the path of the dribbler, before both he and the defending guard (who is typically fighting over the screen) recover. This is a heavily used tactic all over the college game.
• "One man zone" -- the big man defending the screener plays back and attempts to keep both the ball handler and the roll man from getting to the basket, while the guard fights over the screen. The defense in this case is choosing to live with a pull up jumper off the dribble if the ball handler wants to shoot it, although the guard defending is attempting to prevent a three point shot. For a good example of how this works, watch Wisconsin defend ball screens.
• "Ice" -- the guard heavily overplays his man, forcing the ball handler away from the screen, while the big man defending the screener stands in a direct path between the ball handler and the basket. This defense was once mostly confined to the NBA, but now shows up in college as well; Texas has used it frequently this season, with mixed results that seem to relate mostly to poor communication between the two defenders.
• "Trap" -- the guard and big man double team the ball handler, while the other defenders look to guard four offensive players with three men. This is a quite popular defensive tactic that is typically favored by pressure-oriented defenses who are looking to disrupt an offense. It is a more high risk, high reward proposition than the other approaches.
• "Switch" -- if you play pickup, this is probably how you defend ball screens. It is simple; on the ball screen, the two defenders switch responsibilities. This is a less common tactic in the college game, but Kentucky uses it frequently.

The switch is not the most popular way to defend ball screens these days, because it comes at a cost. Switching frequently creates two individual mismatches on the floor, with a big man defending a guard, and a guard defending a big man.

These sorts of mismatches are just the sort of things that NBA teams live to exploit. Isolating a lumbering defender on a quick guard, or creating a mismatch in the low block where an experienced artist can filet his defender is frequently a dream come true.

But at the college level, things don't proceed so cleanly. College teams frequently don't do the best job of exploiting these mismatches. Sometimes they don't even seem to recognize them. Even when they do, they don't often get a very good shot as a result.

Let's talk a little bit about why this is. The image below is taken from late in Texas' win over Baylor. The image was captured in a possession where Texas has switched a ball screen. You will see that Kenny Chery has the ball, and is defended by Prince Ibeh. Meanwhile, Rico Gathers is defended on the low block by Demarcus Holland.

Baylor has a few mismatches to exploit, or at least it thinks it does. But if you watched the game, you know the rest of the story. Chery was isolated on Ibeh, and chose to attack the basket. He looked for a moment as if he would beat Ibeh to the rim, but in the end Ibeh rejected Chery's layup attempt, which preserved the tie for Texas.

Like so many other things in life, basketball is fundamentally an unfair game. While Chery may have the edge over Ibeh in the quickness department, Ibeh's trump card is size. Ibeh is a good enough defender that he isn't all that easy to beat off the dribble, even for a player like Chery. And Ibeh is so much larger that even if he does get beat he can quickly make up the difference, recover and block the shot.

The fact that this isolation on Ibeh did not go well should have come as no surprise to anyone watching the game. Because for nearly the last five minutes of the contest, Texas had been switching virtually every ball screen, with Ibeh and Myles Turner successfully defending a smaller, faster guard each and every time.

Texas' late game ball screen defense

I went back and rewatched the last 10:22 of regulation of the Texas - Baylor game, as well as the five minute overtime. During this 15 minute sequence of the game, I attempted to chart every ball screen that Baylor executed. I think I caught them all, although I could have missed one or two, as Baylor runs a lot of ball screens. (Note that for the purposes of this analysis, I am not treating dribble hand-offs as ball screens. There were a few of these executed as well, although none led to direct scores.)

Over 19 possessions (some of which were transition chances, or quick Baylor turnovers) Baylor ran ball screens 18 times. I classified each ball screen by the way that it was defended. In two cases, the guard refused the screen, and I could not assess the defense's approach. In all other cases it was reasonably straight forward to assign a specific defensive tactic (either intentional or unintentional) to the play.

The table below shows the results. Note that with approximately five minutes remaining in regulation, Texas started defended pretty much every ball screen by switching, and did not give up a single score on a ball screen for the rest of regulation and overtime. The other defensive approaches were mixed and matched prior to this end of game stretch.

Charting Texas' Ball Screen Defense Over the Final 15:22 of Play Against Baylor

Play Type	Occurrences	Points Scored
Guard Rejected Screen	2	0
Hard Show and Recover	4	5
Trap	2	2
One Man Zone	2	0
Switch	8	3
Total	18	10

The Longhorns did give up a single three pointer after switching a screen. This happened with about 9:50 remaining in regulation, when Myles Turner switched onto the ball handler and did an excellent job of containing him. But the play resulted in a three because Isaiah Taylor tried to freelance and made a foolish gamble for a steal, leaving the dangerous Lester Medford open for a three that he buried. This was the play that got Taylor benched until overtime, as Rick Barnes removed him from the game at the next stoppage in play.

Aside from that silly play, Texas' ball screen defense was nearly flawless. Baylor frequently ended up attempting to isolate guards on Ibeh and Turner, and the two mobile Texas big men held their ground. The result was an odd mix of terrible shots by Baylor (including a three point shot that Chery attempted over Turner that didn't come anywhere near the rim), and turnovers where guards attempted to drive into the paint and had to deal with the fact that the person defending them was now a seven foot tall man with bad intentions.

Texas' other ball screen defenses worked to varying degrees. But the simple switch, where there was none of the ambiguity about defensive assignments between the big man and the guard that has caused the Horns so many problems this season, worked wonderfully.

Does this mean Texas' ball screen defense is fixed?

I am not ready to broadly claim the Longhorn perimeter defense is fixed. Texas has blown pick and roll defense frequently this season, and while simplifying and moving to an approach of switching all ball screens from here on out sounds appealing, it may have some pitfalls.

First, is what we saw against Baylor repeatable? We just don't know right now; perhaps another opponent will be better able to take advantage of the mismatches created by switching. Perhaps Ibeh and Turner can't defend in this way all the time.

Then there is the matter of personnel. One can imagine Cameron Ridley struggling with this sort of defense, while his more mobile teammates thrive. When Ridley is on the floor, this sort of approach may not work quite as well.

Finally, there is the question of if it is a good idea to commit to an approach like this, with the inherent mismatch issues that it creates, as opposed to deploying it in short doses as a surprise. And with this comes the additional question of if Rick Barnes would want to commit to this style of defense. I don't have clear answers to these questions.

I absolutely believe that, with the right athletes, switching ball screens can work at the Division I level. Offenses aren't good enough to consistently exploit the mismatches, and are probably better prepared to attack the more common styles of pick and roll defense that they see all the time.

There is no better example of how this can work than in the play of the Kentucky Wildcats, a team blessed with agile big men like Willie Cauley-Stein and Karl-Anthony Towns. The big man doesn't have to be as fast as the man he is guarding; just fast enough to let his size take care of the rest.