As a general rule, advanced stats tend to move in, if not lockstep, at least some reasonable degree of correlation with each other. Higher PER, higher win shares. Higher Win Shares/48, higher Box Plus/Minus. Better BPM, better VORP. And in any combination thereof, when one stat moves, so do the others.
But there’s one very notable exception; PER tends to undervalue catch-and-shoot wings.
Need examples? Well, earlier this week I pointed out that Bojan Bogdanovic has a PER better than league average (15, by definition and baked in the stat) in just one season in his career, namely this one, and he had to shoot 50.5 percent from three to do it.
Khris Middleton is having a monster season in Milwaukee, with a .554 eFG%, .601 True Shooting, .160 WS/48, and nearly 3.0 VORP/82.
But his PER is just 17.9, which is decent but not in line with the borderline All-Star numbers he’s putting up.
And the player whose PER makes the least amount of sense in the entire league? He’s the guy Phoenix is rumored to be shopping around to try to trade him for guard help when he becomes trade-eligible on December 15.
How crazy is Ariza’s PER?
Since 2004, when Ariza was picked 43rd overall by the Knicks in that year’s draft, Ariza’s career PER is 13.3, and the best he’s ever posted in that stat is 16.2, in Orlando in 2006-07, his third year in the league.
Yet Ariza has .097 WS/48, right around the “starter’s Mendoza Line” of .100 (so named because a team with a .100 WS/48 from every player would be expected to win 41 games). He’s got a positive BPM on both offense (0.3) and defense (1.3) for his career. And he’s accumulated 25.6 VORP, an average of over 2.1 VORP per 82 games, which is very strong (it suggests a value of nearly six wins compared to a “replacement player”, as in a guy from the G-League. He hasn’t gone below 1.9 VORP per 82 games since 2008.
In fact, try this stat on for size. (and huge tip of the hat to Basketball Reference’s Play Index for making it possible)
Take every year in which a player posted a PER of 13 or worse since Ariza’s rookie year. Then sort them by VORP.
Ariza has the fourth (2015, 12.7 PER, 2.9 VORP), 13th (2017, 12.4, 2.6), and 15th (2015-16, 12.9, 2.5) seasons out of hundreds in the sample. Further down the list, he’s got Nos. 32 and 33 locked down as well, a total of five seasons in a 15-year sample.
In the top 33, Shane Battier (1, 2, 11, and 21) has four such seasons, Raja Bell (9, 10, and 22) has two, and Bruce Bowen has two of the greatest seasons by a guy who was atrocious on offense (9.1 PER and 2.7 VORP in 2006 and 9.5/2.1 on the Spurs’ title team in 2005) of all time.
Starting to see a pattern developing here?
With all due respect to John Hollinger, who is a brilliant mathematical mind, he created the ultimate stat to undervalue the ever-loving crap out of 3-and-D wings.
In fact, in those top 32 seasons, almost all of them were by guys who were respectable 3-point shooters; only Tyson Chandler (2006, 12.2, 2.2, who didn’t shoot threes at all) and Corey Brewer (2014, 12.7, 2.4, and a dreadful 28 percent from three) are complete exceptions.
Ariza’s not a lights-out three-point shooter by any means (35.3 percent for his career), but he’s always been a workmanlike shooter who does his best work when an offense can create shots for him; this is why he had so much value in Houston.
And yet Ariza had an 11.8 PER last year. In theory, hot garbage. In practice, one of the most sought-after wing shooters and defenders in the league.
You can’t exactly call Ariza a statistical anomaly; he has way too much obvious company in the form of a specific kind of player.
And what’s more, Ariza’s comps tell you exactly what you’re getting. Battier, Covington, Korver, even Metta World Peace (who has two appearances in the top 32) are all guys who played a specific kind of role.
So when the Suns are shopping Ariza, keep that in mind if your team needs a guy who’s a good-not-great shooter and a fantastic defender. If you can play to his strengths, he’s solid. If not, you’re the Suns.