Last season, I looked at 36 centers drafted since 2005 and compared the NCAA college senior statistics of those who completed a season in the WNBA to those who hadn't to figure out whether there were any general patterns in what separates those who are "tall and that's all" from those who might actually make an impact. That sample size is already so small (considering that some didn't compete in the NCAA) that it's difficult to take the next step of comparing starters to non-starters, but the following insights do seem to hold pretty well. So in this situation, "success" is defined simply by making a roster in the year a player was drafted.
- Shooting efficiency: All of the top center prospects in any draft are going to be shooting over 50% from the field simply by virtue of being tall, so while people will talk about field goal percentages, they don't actually matter that much on their own. However, out of those 36 drafted centers from 2005-2009, there did seem to be a pretty clear distinction between the shooting efficiencies of successful and unsuccessful draftees: on average, successful prospects had a true shooting percentage of nearly 60% while unsuccessful ones were almost by rule under 55%.
Free throw rate (FTA/FGA): In keeping with that shooting efficiency marker, free throw rate - the rate at which a player gets to the free throw line - matters quite a bit, and arguably more. Successful centers tended to get to the line at a much higher rate than unsuccessful ones, which could indicate both a knack at getting to the line with quick moves or simply an imposing presence in the paint. I've heard some coaches look at free throw shooting as a proxy for a post player's range and perhaps that could explain a smaller differential in one's rate of free throws produced (FTM/FGA): all of these players are big enough to draw fouls, the best are skilled enough to draw fouls and capitalize. With one exception (Sancho Lyttle), dipping below a rate of free throw rate of under 40% and/or free throws produced under 26% is a harbinger of a short - and at best limited - career to come.
- Value added: So there is an exception to this shooting efficiency rule, which interestingly enough is most pronounced with two undersized centers that have been drafted in this time span (Nicky Anosike and Janel McCarville): if you're not going to score efficiently, it helps to do other things well, whether that be passing, rebounding, or putting up defensive numbers. The value added metric captures some of that. Value added is simply a weighted metric that takes into account everything except scoring. If a player is not a particularly efficient scorer, one "protective factor" is a value added number above 2.22, which is about average among players who have been successful. This pattern is much weaker than the other two but serves as a complementary factor for players that don't have strong numbers otherwise. But one note that is particularly relevant to this year's draft: a negative value added rating has been a sure sign of not making it very long in the WNBA.
Personal foul efficiency (stl+blk/pf): This is an interesting one that like value added isn't a strict rule, but players that fall under the successful centers' average of 1.05 (think of that as a steal and block per personal foul) have not fared well in the league, although a few maintained roster spots.