How much of a team's success can be attributed to the coach?
This has been a long-standing problem, and many metrics have been tried to measure how much of a coach contributes to her team's victories - I've tried a few myself, and some of them pass the smell test. Even so, there are those who will always dismiss a coach by claiming, "oh, with those players anyone could have won!" (In college basketball, this might be true.)So we'll use a metric that we've used before. It's a very primitive metric, which simply ranks each contender for coach of the year in several categories where a coach should have an impact on his team. Each coach receives a value from one to twelve, depending on how she ranks. We use the "close only counts in horseshoes" rule, which means that even if one coach's team ranks a miniscule above the others, the second-place finisher has to accept the full negative impact of the lesser ranking. We only split rankings in case of absolute ties.
The following categories are the ones considered in the ranking.
1. Close games. A good coach should do well in close games. In a close game, the advice given by a coach during timeouts can have a direct impact on the won-loss record of a team. This year, we'll look at won-loss record in games decided by six points or less - games where two baskets could have saved a team from defeat or cost it the victory. These are games where small changes by a coach can make a big difference.
2. Turnovers. The coach might not be able to control for shooting percentage, but should have some control over turnovers. The offense should be designed so that the players can move the ball competently, and within the limits of their capabilities.
3. Offensive rebounds permitted. How much does it say about a coach if her team allows putbacks on missed shots from the opponents?
4. Momentum. This is measured by "streak wins", or counting all sets of wins that are accompanied by a preceding or following win - in short, counting the total wins in all winning streaks greater than or equal to two wins long. A well-coached team builds on its successes and is relatively consistent.
5. Opponent 3-point shooting. Teams should be able to guard the perimeter.
6. Road record. Does the team depend on the coach to help it win, or does it depend on favorable circumstances like a passionate home crowd?
7. Rotation consistency. In essence, a coach should know who she wants to start, and start them.
We use an imperfect tool called the Herfindahl Index. The Herfindahl Index is a basic measure of how well minutes are distributed across all players. There are two extremes: to give all five starters 40 minutes and leave everyone else on the bench, or to split minutes evenly between however many players there are.
Since a good coach shouldn't be looking for bench players to blossom deep into the season - a sign of desperation -we'll favor the first of the two extremes, the extreme of giving a small number of players a great number of minutes. This decision has two consequences - it rewards coaches in the Brian Agler mold who are likely to play their starters high minutes, and it penalizes coaches like Marynell Meadors who were beset by injuries and forces to shuffle minutes to bench players that might have otherwise gone to hurt starters. It's a tough decision, but there's no easy way to measure rotation consistency.
8. Stupid moves. There should be a negative bonus for stupid moves, but there's not much of a way to measure stupid moves. So we ignore this category in our metric.
(* * *)
It's been an interesting year. There have been two teams that lost their coaches in mid stream. Jennfier Gillom was fired by the Sparks and replaced with Joe Bryant, and Nolan Richardson was replaced by Teresa Edwards in mid-season. We'll just say that none of those coaches will be in contention, and leave it at that. We picked up four new coaches this year, some who have been in the league before - John Whisenant (New York), Dan Hughes (San Antonio) and Trudi Lacey (Washington). Only Pokey Chatman of the Chicago Sky is a newly-minted WNBA coach.
Let's look at each of the categories:
1. Close games. The leader in that category is Marynell Meadors' Atlanta Dream. A lot of fans give Meadors a hard time, but if there's any power the Dream has, it's the ability to eke it out when it gets close. The Dream are 8-3 this year in games decided by six points or less, followed closely by Cheryl Reeve's 5-2 Minnesota Lynx. At the bottom is Tulsa at 1-6, which has the power to find a way to lose close games. Furthermore, Minnesota and Tulsa have been in the fewest close games this year - seven each - for different reasons.
2. Turnovers. The Silver Stars are the leader in fewest team turnovers, with 12.73 turnovers per game. Clearly, Dan Hughes' team has figured out a way to avoid turnovers. Surprisingly, Pokey Chatman's Sky lead the league in turnovers with 18.13 turnovers per game - it might be the price to pay for installing a new system.
3. Offensive rebounds permitted. The Lynx lead in this category, controlling the boards and allowing only 7.8 offensive rebounds per game. (The Sparks virtually give away putbacks at the rate of 11.3 per game.) This is one of the few areas where Tulsa is a good team, as the 8.3 offensive rebounds they give up is second best in the league.
4. Streak wins. All of Minnesota's 24 wins are streak wins. None of Washington's six wins are streak wins - even Tulsa has a winning streak this year.
5. Opponent 3-point shooting. John Whisenant's Liberty's defense extends to beyond the white line - New York's opponents only hit 31.2 percent of their 3-point shots. With Trudi Lacey's Mystics, however, it's bombs away as Washington opponents hits almost 40 percent (39.8 percent, to be exact) of their long range bombs.
6. Road record. Minnesota is great both on the road and at home - the Lynx have an away record of 11-4 and their home/away split is virtually identical. In the WNBA, most teams are pretty happy to see the Tulsa Shock, whose road record is 1-13 this year.
7. Rotation consistency. We now break out the Herfindahl indices. The smaller the number, the more "top heavy" the distribution of minutes - it means that there are some players that are eating up all of the minutes.
Some of these numbers come from choice - I suspect that Brian Agler would play five players 40 minutes if he could - and the others come from necessity (who's hurt in Atlanta today?) or a revolving door roster like Tulsa's, which over the last two years have posted staggeringly high index numbers. It looks like John Whisenant is liking who he's seeing in New York, or at least he's decided on a few players that he wants to play consistently.
(* * *)
So when you give each coach a rating from 1 (best) to 12 (worst), which coaches come out on top? This is a case where you want a low ranking....
|LAS||Jennifer Gillom/Joe Bryant||55.0|
|TUL||Nolan Richardson/Teresa Edwards||71.0|
Before someone shouts "this just ends up giving the award to the coach with the best team", it didn't happen that way last year. Even though the 2010 Seattle Storm had by far the most wins in the WNBA, the metric had both Julie Plank of the Mystics and Brian Agler of the Storm neck and neck. The WNBA balloteers gave it to Agler, which proved to be the better choice as the Mystics were rolled out of the first round.
You can't deny that Reeve has done a great job in Minneapolis. Granted, she might have gotten some help in Maya Moore - but Marynell Meadors got help too when she won Coach of the Year in 2009 from both Sancho Lyttle and Angel McCoughtry. Players are performing at a higher level and you can't say that coaching has nothing to do with that.
If there's a dark horse candidate, it should be John Whisenant. Despite Anne Donovan's departure, the Liberty remain respectable and even without components such as Janel McCarville Whisenant is the #2 finisher in the metric. Note that the Liberty are in third place in the Eastern Conference but the metric ranks Whiz higher than Lin Dunn or Mike Thibault, coaches of the teams ahead of the Liberty. Last year's coach of the year Brian Agler comes in at #3.
Just remember: you can only trust a metric so far. The numbers you get should be springboards for discussion, and not holy writ. Even so, I'm convinced that Cheryl Reeve is going to get Coach of the Year in the WNBA this year - and unlike 2004's Coach of the Year Suzie McConnell Serio, let's hope Reeve has a longer tenure in Minnesota.