Celtics' Kemba Walker nearly replicating Kyrie Irving's production, but there's one major area of discrepancy

Correlation does not prove causation. It's a fallacy you're told to watch out for in high school speech and debate classes, but it especially proves true in sports. Just because there's a correlation between two events does not necessarily mean that one caused the other.

As we head into Wednesday night's matchup between the Boston Celtics and Brooklyn Nets, it's easy to look at the Celtics' early success this season and point the finger at Kyrie Irving: "Look, Kyrie left and now the Celtics are unstoppable! It was all his fault! The earth is once again round!" Yes, many of last year's Celtics, including Irving himself, have noted the poisonous locker room situation that led to a disappointing 2018-19 season, but suggesting that Boston's hot start is solely the result of Irving heading to Brooklyn in free agency is shortsighted and unfair.

The most intriguing part of the equation is that Celtics president Danny Ainge managed to replace Irving with a near identical double -- statistically, at least -- in Kemba Walker. As you'll see below, by most measures this season, Walker has come extremely close to reproducing Irving's contributions, and in some cases has exceeded them.

Stats aren't the whole story, of course. There have been rave reviews about how well Walker is fitting in with his new team, beginning with chemistry built between him, Jaylen Brown, Jayson Tatum and Marcus Smart with Team USA this summer. There hasn't been one public or reported complaint about the former Hornet -- but then again, there were no complaints about Irving as Boston rattled off 16 straight wins early in his Celtics tenure during the 2017-18 season.

Things change rapidly in the NBA, so for now all we can do is look at the present. And as it stands, Walker is doing a tremendous job filling in for Irving in Boston. Here's a look at how Walker's 2019-20 season so far compares to Irving's 2018-19 production.

*All stats from NBA.com and Synergy, accurate as of Nov. 26

Counting Stats

Counting Stats with CelticsPTSASTREBSTLTOV

Kemba Walker (2019-20)

21.1

4.7

4.6

0.9

2.1

Kyrie Irving (2018-19)

23.8

6.9

5.4

1.1

2.6

The biggest discrepancy here is in assists, where Irving averaged about two more than Walker. This is somewhat unexpected, because both joined the Celtics with identical career assist averages of 5.5. It is important to note, however, that Irving averaged 5.1 assists during his first season with the Celtics in 2017-18. Otherwise, outside of Irving scoring a couple more points per game, the stats are pretty close.

Efficiency

Efficiency with CelticsFG%3P%FT%PPP

Kemba Walker (2019-20)

40.0

38.9

91.7

1.016

Kyrie Irving (2018-19)

48.7

40.1

87.3

1.056

Efficiency is the biggest difference between the two so far. Last season Irving was remarkable in this regard, putting up nearly 50-40-90 splits on significant volume. Walker's career averages suggest he'll get somewhere around the 43 percent mark from the field, but even that would fall well below Irving's mark. The discrepancy in points per possession is also significant, as Irving was one of the best in the league in that area last season.

Possession

Per game with CelticsTouchesSec per touchDribbles per touchPTS per touch

Kemba Walker (2019-20)

73.7

4.9

4.46

0.287

Kyrie Irving (2018-19)

76.8

4.27

3.91

0.310

There's a contingent out there that believes part of why Irving didn't lead to Celtics success is that he's, for lack of a better term, a ball hog -- a tremendous individual scorer who sometimes hurts the offense by stopping the ball. These stats, however, indicate that Walker actually holds the ball longer and dribbles more than Irving did last season, while scoring less efficiently. For those interested, Walker has actually passed the ball fewer times per game (49.5) than Irving did last season (51.3).

Isolation

Isos with CelticsIso%PPPPercentile

Kemba Walker (2019-20)

8.3%

1.038

76%

Kyrie Irving (2018-19)

13.2%

0.975

74%

While the touches and time of possession are relatively equal, the stats definitely back up the eye test that Irving ran isolations more often than Walker has. Irving ended up with scoring chances out of isolation 13.2 percent of the time last season, while Walker is at 8.3 percent. It appears that Walker has chosen his spots wisely, however, as he has put up a strong 1.038 points per isolation possession.

Defense

Defense with CelticsOpp. PPPPercentileDeflectionsContested Shots

Kemba Walker (2019-20)

0.961

34%

2.1

7.5

Kyrie Irving (2018-19)

0.908

62%

2.5

5.3

Take any set of defensive stats with a grain of salt, since so much of defense depends on teammates. For example, Irving had Horford and Baynes to offer help and protect the paint, while Walker doesn't. While neither Irving nor Walker is considered a defensive stalwart, Walker's height (6-0) compared to Irving's (6-2) may play a part, as Walker's opponents are scoring significantly more efficiently on jump shots this season -- even though Walker is contesting more -- perhaps because they have an easier time shooting over the top.

Clutch

Clutch stats with CelticsPTSFG%3P%Usage%

Kemba Walker (2019-20)

4.0

39.1

46.2

34.5

Kyrie Irving (2018-19)

4.3

49.6

36.6

42.8

There's no doubt that Irving was the Celtics' go-to player in clutch situations (games within five points with five minutes remaining) last season, as was Walker in Charlotte. This season the stats say that Boston has spread the wealth a little bit more down the stretch, and Walker has scored less and had less usage than Irving as a result. Irving was spectacularly efficient in such situations, but Walker has been lights out from 3-point range late in the fourth quarter.

On/Off Court

Celtics Net RatingOn CourtOff CourtDifference

Kemba Walker (2019-20)

+8.0

+6.5

+1.5

Kyrie Irving (2018-19)

+6.2

+1.6

+4.6

Overall the Celtics are playing better with Walker both on and off the court, while the drop-off when Irving sat last season was much more severe. The bottom line is that the Celtics have been more efficient this season overall, so you would expect the on/off court numbers to reflect that. The offense has been worse with Walker off the floor than it was with Irving, but defensively the Celtics have been an absolute juggernaut with Walker on the bench, allowing just 94.8 points per 100 possessions.

Conclusion

It's too early to draw significant conclusions or predictions about how well Walker will fill in for Irving, but it certainly appears that Walker is well on his way to approximating the production. Efficiency, however, is the biggest area of discrepancy -- Irving made the most of his shot opportunities in a way that Walker has yet to duplicate. What you can't measure is the impact that Walker's had in terms of chemistry and leadership, but the wins and losses indicate that he's doing well in that regard. After experiencing his fair share of losing in Charlotte, Walker is relishing his new surroundings.

"I love this winning, I can't lie to you," Walker said after the Celtics beat the Warriors for their 10th straight win earlier this season. "I've never won this many games in a row. I've never had a start like this. I'm just liking the way I'm feeling after the games. I'm just feeling good. That's all I'm thinking about. I'm really just taking it in."

Our Latest Stories