Measuring a Coach’s Success


Neil Paine of Basketball Prospectus published an interesting post to “quantify” potential coach of the year candidates. Toronto coach Dwane Casey screens well, as you might have expected.

His first screen was based on year over year improvement in winning percentage.

Coach Casey ranks a solid 5th. However, as Mr. Paine points out, “there has to be a better way of accounting for the raw talent on a team beyond simply using the franchise’s previous W-L”. Certainly, player changes (such as LAC’s addition of Chris Paul) should be considered.

Here’s where Daniel Myers’ Advanced Statistical Plus/Minus (ASPM) is valuable.

In essence, ASPM is a boxscore-based, more stable version of Regularized Plus/Minus that is probably the most predictive all-in-one advanced box-score stat out there right now. Denominated in efficiency differential, ASPM is ideal for projecting a team’s performance via a minute-weighted average of the individual ratings of its players. – Neil Paine

Coach Casey still ranks well, but drops to 8th using this methodology:

If he had a healthier Andrea Bargnani, Jose Calderon, and Jerryd Bayless he would likely have screened much better. Starting two 10-day contract players isn’t ideal if you’re trying to win games, yet he’s pulled out a couple.

Advanced Statistical Plus/Minus

Speaking of ASPM, it revealed what I thought may be true: the Raptors do not have any good “two way” players:

I like the ASPM methodology and the presentation of both offensive and defensive scores. It also appears to meet the “eye test”. Most Raptors’ observers would agree Bargnani, Calderon and Bayless are solid offensive weapons, yet are not as effective on defence. Meanwhile, James Johnson, Amir Johnson, Ed Davis and Aaron Gray are solid defenders, but struggle to varying degrees on the offensive end. What’s glaring is the absence of any player in the quadrant for both positive offensive and defensive production.

Questions? There is a dedicated to “Statophile Q&A” forum thread here . If you prefer to send questions privately, you’re welcome to email me at tomliston [at] gmail [dot] com or find me on Twitter (@Liston).