Anticipating breakout candidates requires assessing opportunity and ability. Those two lanes are merging in Los Angeles with Tobias Harris, the scoring swing forward now playing with the Clippers. Harris was phenomenal for the team after being acquired at the trade deadline in the Blake Griffin blockbuster, and after the departure of DeAndre Jordan this summer, Harris may become the de facto face of the franchise.

Clippers head coach Doc Rivers mentioned how impressed he is with Harris back in March after the team acquired him:

“First of all, he’s better than I thought. I knew he was a good player. We didn’t know how good. He’s just so efficient offensively. He’s a way better shooter, even though all the numbers said he was. You just don’t see that he is. He’s better off the dribble. Terrific post game. So he really does the three things you need to do offensively. And at his size, he’s a nightmare to match up with. Threes don’t want to guard him because he’ll post and he’s quicker than most fours. So he’s a really, really good basketball player.”

The perception of Harris around the league might mirror how Rivers began to view Tobias after his breakout campaign. Averaging 18.6 points, 5.5 rebounds and 2.4 assists per game last season while shooting 46 percent from the field and 41 percent from three has brought Harris to light as one of the players primed for an even stronger campaign next season. Rivers accurately assesses the offensive profile and strengths he holds in today’s league, exploiting whichever type of defender he draws based on a well-rounded offensive prowess. All the tools are there for him to put up big numbers while remaining efficient.

While his versatility on that end of the court is highly sought-after, Harris may be lacking in terms of his defensive production. As he adjusts to his role with the Clippers as their No. 1 option and go-to scorer, his raw numbers should remain high, causing him to become a trendy breakout pick for All-Star recognition.

But regardless of his scoring output, his defensive aptitude and attention to detail might bring pause to the many watching for a huge jump in perception.

Understanding Different Defensive Metrics

Two massive gripes I have with using analytics to evaluate defensive impact is that most statistical measures are either estimates or incomplete assessments, and that several important defensive plays aren’t quantifiable. Using readily-available metrics on sites like Basketball-Reference requires a great deal of understanding about what each means. Likewise, a positive number doesn’t always mean a defender is above-average, and a negative mark might have more backstory.

Defensive win shares (DWS) is the first—and perhaps most dangerous—statistic available, as it is directly related to the amount of playing time someone receives. Defensive box plus/minus (DBPM) does better in comparing a given player to the league average and attempts to account for most quantifiable variables. But in order to achieve high individual scores on most defensive metrics, players must be statistically credited with a measure (defensive rebounds, steals, blocked shots).  Those do not encapsulate complete positive impact on a defensive possession.

How would one attribute value to Tobias Harris for his impact on this possession?

The Clippers are trapping against the Milwaukee Bucks whenever they see a high pick-and-roll. DeAndre Jordan and Austin Rivers swarm Khris Middleton, who keeps his eyes on the rim and looks for an open target. On a trapping ball screen, the screener is usually the open man—unless someone rotates to pick him up. Harris makes such a rotation away from the opposite corner and towards the front of the rim. You can see Middleton double-clutch, and with poor spacing on the weak side, he throws the ball away.

Synergy Sports Tech breaks its metrics down by play type and logs this as a pick-and-roll opportunity. Austin Rivers is credited as the primary defender, DeAndre Jordan defending the screener and Milos Teodosic with the steal. But it’s really Harris who helps cause the turnover, even if he will see zero individual uptick in this measurement of his defensive performance. Seems like a bit of a flawed system.

The best solution to assigning defensive value might be to look at only team statistical measures. What matters most is how a team performs when a player is on the court, not whether one individual is responsible for the team’s performance. Team performance, evaluating the difference between when a player is on the court and when he is off it, is the most accurate look we have.

Those numbers don’t bode well for Harris during his time with the Clippers. When he was on the court, Los Angeles gave up 5.3 more points per 100 possessions than when he was off, placing him in the bottom 10 percentiles across the league in defensive impact. That number was worse in Detroit, where the Pistons gave up 7.8 more points per 100 possessions with Harris in play.

Even those metrics might need to be taken with a grain of salt. The five-man unit is ultimately a reflection of the defensive prowess of all five players. Who was on the court with Harris greatly impacted those lineups metrics. Per Cleaning the Glass, only seven five-man Clippers lineups including Harris played at least 100 possessions together. Of those seven, only two were in the bottom third of the league in points per possession and effective field-goal percentage rates. Those two lineups were porous three-guard outfits featuring both Austin Rivers and Lou Williams. How would those numbers change if Harris were slotted in with Avery Bradley and Patrick Beverley—two of the better on-ball defenders in the league?

Some other lineups featuring Harris fared quite well. The grouping of Rivers, Avery Bradley, Harris, Danilo Gallinari and DeAndre Jordan only ceded 92.4 points per 100 possessions—a rate far better than league average. Meanwhile, every one of those remaining five-man units featured Jordan at center. Jordan, long considered a high-caliber defensive player, saw the Clippers give up 2.8 more points per 100 possessions than when he was on the bench. Few would argue he was a worse and less impactful defender than his backups last season.

So the moral of the story? Five-man units are easily sabotaged by poor defenders, therefore they’re not complete explanations of individual effectiveness across the board.

There may not be an accurate way to best interpret the defensive metrics of any individual player, and that’s exactly the point. Defensive statistics can be manipulated in any direction to either illustrate a player’s weaknesses or excuse them. Film study, team metrics and a dash of individual impact measures all go into determining whether a player has a positive defensive contribution to his team.

In regards to Harris, we don’t know whether his statistics are poor because he’s a below-average defender or because his teammates aren’t of high enough quality to post strong five-man numbers. So much in the game of basketball is relative, and the answers to understanding the relativity lie within game tape.

Evaluating his Defensive Impact

A long and athletic 6’8”, Harris has routinely drawn the top defensive assignment against scoring forwards. Not being an elite defender, his on-ball metrics can suffer as a result. Since joining the Clippers, he played for Doc Rivers, who would frequently ask his team to switch ball screens. That exposed him to many types of assignments, player types and, above all, time spent guarding the basketball.

While Harris can check multiple types of players, that versatility is only a strength if he is effective in those multiple areas. He hasn’t demonstrated such a skill. Harris has been torched by quick moves in the post or in isolations when guarding high-caliber players. Often his feet will plant in one spot, and he’s a split-step behind in cutting his man off from the basket:

When Rivers tasks Harris with switching on a screen, he does so aggressively, trying to catch the ball-handler off balance and cause him to recoil. If done successfully, it will negate any advantage usually gained at the point of the screen. However, his aggressiveness can be a detriment, taking too long of a stride and jumping out beyond the screen, which actually gives his opponent a lane to the basket. The key to switching a screen is to do so tight enough to where the action cannot get “split,” meaning the ball-handler has space between the screener and his defender to drive right to the rim:

Those are clear errors on Harris as the man who switches into the responsibility of stopping the ball.

He’s shown to be a bit of a sucker for quick-burst moves after a hesitation, too. Often, bigger players who end up on a small guard will play a bit further back, using their length to shadow a shot or pass attempt while giving themselves cushion against a drive to the hoop. Here, Harris gets caught between jamming CJ McCollum with an aggressive switch and playing back to protect against a rim attack. One stutter-step and dribble move from McCollum freezes Harris and gets him to open his hips too much, creating a clear lane to the basket:

The frustrating part with Harris is that he’s proved capable of defending guards off switches when he’s engaged. While he opened his hips up at a poor angle against McCollum, this defense against Victor Oladipo at the end of a quarter was stellar:

Displaying great mechanics with his feet, he shows his naval to the ball and puffs out his chest to cut off the drive, then he uses that great length to contest the step-back with a perfectly-balanced closeout. It’s as good as anyone can do in that situation, and proof that he has all the tools to be an above-average defender.

Tricky three-man actions in crowded spaces tend to give Harris the most trouble. His gait brings incredibly long strides, but he’s not quick in tightness, so he struggles to navigate crowds and change direction with the ball. In the action below against the Philadelphia 76ers, there’s a ton of movement, all of which is centered around getting the ball to Ben Simmons going to his left. Harris is unable to get through the action and gets hung up on Joel Embiid, leading to a dunk:

Off the ball, Harris is just as inconsistent.

He’s proved able to stay engaged in different coverages, helps where he should when guarding shooters in the corners and has a nose for the ball as a rebounder. But against some players, he still struggles to come up with the right read. More times than not, Harris gets in trouble from over-helping, either running toward the ball and leaving his man by a step too much or jumping into a standard help position when that isn’t his assignment.

Watch here against the Phoenix Suns after a standard floppy set. Alec Peters, a fairly one-dimensional stretch-shooting threat who Harris is marking, floats from the elbow to the three-point line. Harris leaves to help on a baseline drive when he shouldn’t, gets lost navigating the traffic and leaves Peters with a wide-open three from the wing:

Harris may accumulate the offensive volume to become a borderline All-Star, but his defense could continue to hold him back. His on-ball work is suspect, and his showings in help situations are generally hit or miss. There’s enough evidence to show that, when engaged and against the right matchups, he can be a solid defender.

But now, it’s a matter of will, not ability.

This season, with Harris flanked by more plus defenders and a stronger backcourt, we may finally know whether his sporadic team defensive metrics are attributed to him or to the poor defenders around him. Just be warned: The answer may not be too friendly to those who consider Harris an All-Star breakout candidate.

Unless otherwise noted, all stats are courtesy of Basketball-Reference, Synergy Sports Tech or NBA.com.