WNBA: Player Efficiency Ratings for 2009

Attached are John Hollinger's Player Efficiency Ratings (PER) for 2009. If you want to know more about PER ratings, you might want to the Wikipedia article about PER and how it works.

PER is an "all-in-one" metric and has the faults of an all-in-one metric. Whenever you try to describe a player using one numerical stat - even if that stat purports to sum up all that player accomplishes - there is the danger of losing information. Metrics suffer from what I call the "gamer's dilemma" - the fewer numbers, the greater the chance of losing information; the more numbers, the more complex and unwieldy the metric.

There are other problems with PER. It doesn't measure defensive statistics very well, but no basketball metric does. It is not an additive metric, which means that player who played limited minutes have a chance of scoring a very high PER. (See Sherill Baker.) It also rewards inefficient shooting.

So what's good about PER? First, PER takes into account individual team paces as well as how well players and teams perform against the WNBA average. Teams with a fast pace like the Mercury can't stack up points the way they would in an additive metric.

Furthermore, it's easy to understand. The league average player has a PER of 15.00. This is a deliberate choice; all PER ratings are normalized to force the league average player to be at 15.00. There is also a scale that Hollinger provides for PER:

A year for the ages: 35.0
Runaway MVP candidate: 30.0
Strong MVP candidate: 27.5
Weak MVP candidate: 25.0
Bona fide All-Star: 22.5
Borderline All-Star: 20.0
Solid 2nd option: 18.0
3rd Banana: 16.5
Pretty good player: 15.0
In the rotation: 13.0
Scrounging for minutes: 11.0
Definitely renting: 9.0
Next stop: Latvia: 5.0

So what can PER tell us about the 2009 season?

Sherill Baker - who played one game - is not the very best player in the WNBA this year. Baker shot 2-for-3 in her lone game and PER rewards her greatly. You have to keep in mind that PER only means something if the player has a lot of minutes.

Seimone Augustus's injury hurt the Lynx a lot. If Augustus could have kept that 30+ PER all season, it would have been one of the WNBA's great seasons. Only eight WNBA players have managed a PER of 30+ while also playing significant minutes. The best? Lauren Jackson's PER of 34.72 in 2006.

Furthermore, the argument could be made that Jackson deserved the MVP over Taurasi. However, Taurasi played more minutes than Jackson (976 vs. 843) and also played the Mercury to a WNBA title. Despite Jackson's higher rating, the MVP voters made the correct decision.

Who was the real Rookie of the Year? If you believe PER, it's Angel McCoughtry, who makes it to the Top 10 in players with significant minutes.

You can even judge - or try to judge - trades if both players played enough minutes. Take the Tamera Young/Armintie Price trade. One problem with PER is since that it's based on performance relative to team/league, a player can have two different PERs if they played with two different teams. (I suppose you could weight each component PER by minutes played on each squad and built an overall PER for the player.)

Before the trade, Young had a 12.05 PER with the Dream and Price had a 10.48 PER with Chicago. They seemed to be fairly equal players. Afterwards, Young's PER went up to 14.34 during her time with the Sky. Price's PER, on the other hand, collapsed to 4.23 with the Dream. There were considerations other than talent that necessitated that trade - Young and her agent essentially forced the trade - but the trade was more of a bonus to the Sky than it was to the Dream.

So here are the 2009 Player Efficiency Ratings. If you have a problem with the results, don't call me - call John Hollinger. I hear he's on Twitter!

Sherill Baker DET 33.26
Seimone Augustus MIN 31.12
Lauren Jackson SEA 26.08
Diana Taurasi PHO 25.30
Nicky Anosike MIN 24.38
Becky Hammon SAS 23.54
Khadijah Whittington IND 23.47
Angel McCoughtry ATL 23.19
Tamika Catchings IND 23.14
Lisa Leslie LAS 22.86
Rebekkah Brunson SAC 22.39
Cappie Pondexter PHO 22.18
Kara Braxton DET 22.14
Janel McCarville NYL 22.01
Charde Houston MIN 21.77
Kristi Cirone CON 21.64
Sophia Young SAS 21.50
Nicole Powell SAC 21.32
Sancho Lyttle ATL 21.32
Jia Perkins CHI 21.10
DeWanna Bonner PHO 21.04
Candace Parker LAS 20.80
Katie Douglas IND 20.53
La'Tangela Atkinson SEA 20.08
Erika Desouza ATL 19.97
Lindsay Whalen CON 19.69
Shay Murphy IND 19.59
Penny Taylor PHO 19.52
Shameka Christon NYL 19.44
Courtney Paris SAC 18.91
Candice Dupree CHI 18.91
Crystal Langhorne WAS 18.85
Kristi Toliver CHI 18.77
Asjha Jones CON 18.75
Mistie Williams CHI 18.25
Le'coe Willingham PHO 18.06
Shanna Crossley SAS 17.97
Ann Wauters SAS 17.40
Deanna Nolan DET 17.35
Sylvia Fowles CHI 17.11
Tan White CON 17.01
Janell Burse SEA 16.91
Alana Beard WAS 16.64
Tanisha Wright SEA 16.24
Shavonte Zellous DET 16.14
Yolanda Griffith IND 16.14
Tammy Sutton-Brown IND 16.07
Megan Frazee SAS 16.05
Betty Lennox LAS 16.00
Noelle Quinn LAS 15.95
Sue Bird SEA 15.63
Taj McWilliams DET 15.59
Hamchetou Maiga-Ba SAC 15.51
Erin Thorn CHI 15.25
Monique Currie WAS 15.10
Shyra Ely CHI 14.93
Sandrine Gruda CON 14.93
Erin Phillips CON 14.92
Marie Ferdinand-Harris LAS 14.89
Chamique Holdsclaw ATL 14.85
Roneeka Hodges MIN 14.78
Tangela Smith PHO 14.69
Amber Holt CON 14.63
Michelle Snow ATL 14.61
Lindsey Harding WAS 14.51
Tiffany Jackson NYL 14.43
Temeka Johnson PHO 14.38
Tamera Young CHI 14.34
Jessica Davenport IND 14.31
Renee Montgomery MIN 14.17
Edwige Lawson-Wade SAS 14.04
Katie Smith DET 13.94
Kerri Gardin CON 13.91
Camille Little SEA 13.70
Kara Lawson SAC 13.63
Tasha Humphrey MIN 13.56
Ivory Latta ATL 13.52
Lindsay Wisdom-Hylton LAS 13.43
Laura Harper SAC 13.05
Kristin Haynie DET 13.05
Quanitra Hollingsworth MIN 13.04
Tina Thompson LAS 12.96
Erlana Larkins NYL 12.86
Swin Cash SEA 12.76
Essence Carson NYL 12.64
Vickie Johnson SAS 12.60
Ebony Hoffman IND 12.53
Olayinka Sanni DET 12.44
Cheryl Ford DET 12.43
Matee Ajavon WAS 12.37
Tully Bevilaqua IND 12.37
Chasity Melvin WAS 12.12
Belinda Snell SAS 12.07
Tamera Young ATL 12.05
Katie Gearlds SEA 12.02
Ashley Battle NYL 11.95
Ruth Riley SAS 11.93
Kia Vaughn NYL 11.90
DeMya Walker SAC 11.80
Briann January IND 11.80
Vanessa Hayden LAS 11.74
Crystal Kelly SAC 11.66
Anete Jekabsone-Zogota CON 11.54
Ticha Penicheiro SAC 11.53
DeLisha Milton-Jones LAS 11.52
Cathrine Kraayeveld NYL 11.44
Katie Feenstra SAS 11.36
Kiesha Brown CON 11.23
LaToya Pringle MIN 11.22
Nicole Ohlde PHO 11.09
Kristin Haynie SAC 11.06
Loree Moore NYL 11.05
Dominique Canty CHI 10.98
Anna Montañana MIN 10.94
Sidney Spencer NYL 10.85
Marissa Coleman WAS 10.72
A'Quonesia Franklin SEA 10.60
Armintie Price CHI 10.48
Coco Miller ATL 10.37
Alexis Hornbuckle DET 10.33
Chante Black CON 10.11
Chelsea Newton SAC 9.91
Nakia Sanford WAS 9.81
Iziane Castro Marques ATL 9.77
Tamecka Dixon IND 9.76
Scholanda Robinson SAC 9.65
Crystal Kelly DET 9.18
Kristen Mann WAS 9.15
Lauren Ervin CON 9.03
Erica White IND 9.01
Kristi Harrower LAS 9.01
Nikki Teasley ATL 8.87
Shalee Lehning ATL 8.73
Chen Nan CHI 8.73
Jessica Moore IND 8.61
Shannon Johnson SEA 8.52
Whitney Boddie SAC 8.40
Kelly Miller MIN 8.04
Kelly Mazzante PHO 7.74
Ketia Swanier PHO 7.67
Helen Darling SAS 7.64
K. B. Sharp CHI 7.62
Rashanda McCants MIN 7.54
Leilani Mitchell NYL 7.49
Christina Wirth IND 7.45
Brooke Wyckoff CHI 7.44
Nikki Teasley DET 7.29
Bernice Mosby WAS 6.69
Tamika Whitmore CON 6.67
Shannon Bobbitt LAS 6.67
Katie Feenstra CHI 6.63
Nikki Blue WAS 6.42
Jennifer Lacy ATL 5.84
Erin Buescher SAS 5.83
Candice Wiggins MIN 5.76
Barbara Turner CON 5.72
Brooke Smith PHO 5.45
Suzy Batkovic SEA 5.00
Barbara Farris DET 4.63
Anna DeForge DET 4.47
Armintie Price ATL 4.23
Ashley Walker SEA 3.79
Tasha Humphrey WAS 1.53
Allie Quigley PHO 1.51
Kelly Schumacher DET -0.29
Britany Miller DET -0.59
Tanae Davis-Cain DET -0.83
Ashley Robinson SEA -1.56
Plenette Pierson DET -5.16
Christi Thomas MIN -6.99
Lisa Willis SAC -31.25