Point guard of the WNBA Seattle Storm Sue Bird contributed to a recent installment of the 538 podcast HotTakedown. Bird’s appearance was precipitated by an op-ed she authored for the Player’s Tribune illuminating the paucity of accessible, informative data for the WNBA and for female sports more broadly. Days later, hysteria followed comments made by a veteran sports writer regarding the unprecedented dominance of the UConn women basketball team. The implications of that writer’s statement have been summarized elsewhere.
After listening to Sue Bird on the 538 podcast and before learning of the galvanizing comments, I watched much of Uconn’s decimation of Mississippi State. I watched because I enjoy that sort of competitive dominance; plus, their team is just good. I’ve yet to write about it here but I also watched because I love basketball. After hearing the galvanizing comments, all I could think was: with increased access to informative data and with an array of perspectives creating narratives using such data, maybe a weakness would be identified.
Admittedly, I watch less female than male basketball but that is partly attributable to the greater viewing options for the latter. In my opinion, the female game demands greater acceptance of and adherence to strategy. Also, it appears that fewer female players exhibit an inclination to rely on and expect officiating. There are absolutely aspects of female basketball that I prefer. That should be unsurprising—consider the blog title—because there is simply less palming of the ball, at least in my observational comparisons of the female and male varieties.
Indeed, there is diversity and variety in the female and the male games. This post is devoted to a simple exploration of that variety. The data in Table 1 was computed using league-wide WNBA and NBA data from the 2015 and 2014-15 regular seasons, respectively. Data from Basketball Reference. Possessions were estimated with an equation used by ESPN.com and NBA.com, developed I believe by legend Dean Oliver.
Indeed, there is diversity and variety in the female and the male games. This post is devoted to a simple exploration of that variety. The data in Table 1 was computed using league-wide WNBA and NBA data from the 2015 and 2014-15 regular seasons, respectively. Data from Basketball Reference. Possessions were estimated with an equation used by ESPN.com and NBA.com, developed I believe by legend Dean Oliver.
| SHOOTING | ||
|---|---|---|
| STAT | WNBA | NBA |
| FG% | 42.5% | 44.9% |
| 3FG% | 32.5% | 35.0% |
| 2FG% | 45.4% | 48.5% |
| FT% | 79.5% | 75.0% |
| % of FGA are 2PA | 77.4% | 73.2% |
| % of FGA are 3PA | 22.6% | 26.8% |
| Assists / FGs | 58.7% | 58.7% |
| Blocks / FGA | 6.6% | 5.7% |
| FT / FGA | 22.6% | 20.1% |
| FTA / FGA | 28.4% | 27.3% |
| POSSESSIONS | ||
| FGA / POSS | 0.877 | 0.897 |
| Fouls / POSS | 0.248 | 0.217 |
| Turnovers / POSS | 0.173 | 0.154 |
| Steals / POSS | 0.096 | 0.083 |
| Pts / POSS | 1.008 | 1.073 |
| Pts / FGA | 0.923 | 0.992 |
| Pace | 88.7 | 92.5 |
A few items of note upon review of this table. Offenses in both leagues rebound their own misses at similar rates and assist FGs at essentially identical rates. The pace of the NBA game is somewhat faster. In the WNBA there appears to be a greater proportion of dead-ball rebounds the cause of which is unclear. Also, for what it’s worth, the NBA teams scored .069 points per possession more than did WNBA teams.
Before concluding, I would like to provide some depth to the discrepancies in FG% between the two leagues. NBA players tallied 8793 successful dunks in 2014-15 season. From what I can ascertain, there were maybe 2 dunks in the 2015 WNBA season. Successful dunking is nearly guaranteed, although NBA did make only 91% of dunk attempts. Contrarily, NBA players sunk 27,080 lay-ups that season at a clip of 58%. As you know, we don’t have that sort of data for the WNBA; well, at least I don’t.
So how does the discrepancy change if we exclude all dunk attempts from the computation of NBA FG%? We’ll even remove the 2 WNBA dunks. Excluding dunk attempts, NBA FG% drops from 45% to 40%. Considering that FG%, WNBA players appear to shoot a higher percentage that is statistically significant, but it is a small effect.[1] Now, it should be noted that the WNBA players do play with a slightly smaller and lighter-weight ball, about 96.6% the circumference of the NBA ball and 91% the weight of the NBA ball but the rim diameters are equal. Thus, the argument could be made that there is a greater area of the basket plane available for the WNBA ball to enter the basket.
There is evidence to suggest that basketball of light weightwill facilitate increased FG%. We do know that Illinois males played Oakland in December 2010. The first 7:22 of game time was played with the slightly smaller ball used by females. Illinois did shoot 3 of 13 in that time and Oakland shot 7 of 16. That is a small sample, however, there appears to be a lack of effect of ball size on free throw shooting percentage and on shooting kinematics. Moreover, one study compared collegiate 71 female and 35 male basketballers. Neither an effect of ball size nor weight was found for on “side shots” (elbow jumper) and “lay ups” but smaller, lighter balls were passed fastest by both sexes.
I provided in this post a comparison of the WNBA and NBA league-wide team data. However, I was not attempting a comparison, per se. More precisely, I attempted to highlight the variety of game-play in each League and how that variety manifests statistically because, when informative statistics are tracked for female basketball, it is not enough to simply adopt existing metrics from the male game—ecological considerations specific to the female game are warranted. Simple calculations were used to demonstrate how the high-percentage of successful dunking inflates FG%s in the NBA. Likewise, the effect of ball-size was considered. In sum, this exploratory analysis indicates several avenues of further study of the statistical manifestations of female basketball including, the high proportion of dead ball rebounds and slight differences in turnovers, fouls, steals, and blocked shot-attempts to their male counterparts.
[1] χ2(df = 1, N = 27055) = 103.35, p < .001, Ṽ = .061.
