Field goal percentage - the ratio of field goals taken to field goals attempted - is usually an argument settler when comparing two players of otherwise equal characteristics. After all, if you have two shooting guards and one is shooting .425 and the other is shooting .400, the first must be a better shooter than the second - right?
Not necessarily. Suppose we could take a look at each shot these two players makes. What if the first player is taking all of her shots from very close range and the second player takes her shots from farther out? The first players degree of difficulty has been reduced compared to the second player who made more difficult shots. Which is more impressive - .425 from close up or .400 from farther back.
As expected, the closer you are to the basket, the more likely it is that you will make your shot. The 2013 WNBA overall percentages by distance are:
0.564 - 1-to-5 feet from basket
0.350 - 5-to-10 feet from basket
0.362 - 11-to-15 feet from basket
0.357 - 16-to-20 feet from basket
0.334 - 21-to-25 feet from basket
0.277 - 26+ feet from basket
In general, shooting accuracy declines by distance. Is there a way to adjust a player's shooting performance by the distance from the hoop?
As it turns out, the Minnesota Lynx website has shooting data for each WNBA player by distance from the goal. All shots each WNBA player has made over 2013 have been divided by distance into the six categories above.
For example: out of Janel McCarville's 79 total field goals this year (out of 162 field goal attempts)
39 of 56 were made from 1-to-5 feet
2 of 6 were made from 6-to-10 feet
9 of 21 were made from 11-to-15 feet
23 of 65 were made from 16-to-21 feet
6 of 14 were made from 22-to-25 feet
0 of 0 were made from 26+ feet
So how do her shots in each distance category compare to the WNBA average? Is she better than or worse than the WNBA average from 1-to-5 feet? The WNBA average percentage is .564, so a hypothetical average shooter would make 31.57 shots out of 56 attempts from 1-to-5 feet. From that same distance, McCarville made 39 field goals. It looks like Janel McCarville is much more accurate from close range than your hypothetical average point-blank shooter. This should be expected, given the position she plays.
We then ask the same question for McCarville's 6-to-10 feet range shooting. Is 2-for-6 better than or worse than the WNBA average? For the average WNBA player taking six shots from 6-to-10 feet, the average would be 2.10 shots made.
We keep doing this for every category and compare the sum total of shots made by the hypothetical average shooter, adjusting by distance in each category, to McCarville's overall total.
McCarville total: 79 field goals
Distance-adjusted WNBA average player: 69.19 field goals
The conclusion is that McCarville is a very effective shooter, adjusting for where she shoots on the court. We'll express her effectiveness as a ratio of player shots vs. ditsance adjusted average shots. In which case, her effectiveness ratio is 1.142, which is 10th among all WNBA players in 2013.
Let's look at all WNBA players who made 100 or more shots this season and rank them by effectiveness ratio. FG/AvgPlr are the fields goals made by a hypothetical WNBA player after adjusting by distance.
|2013 WNBA Shooting Effectiveness Ratio|
|(min 100 FGA)|
|de Souza, Erika||Atl.||187||164.13||1.139|
|Delle Donne, Elena||Chi.||172||158.56||1.085|
|Castro Marques, Iziane||Con.||58||68.11||0.852|
The list above begs a few questions, namely if post players will automatically jump to the top. Post players made the majority of their shots from close range, and the WNBA league average includes non-post players. It sure looks that way, but note the appearance of Kara Lawson, Kristi Toliver and Diana Taurasi in the top 10. Leilani Mitchell has a high effectiveness rating in the shots she takes, given her position.
Note out of all the players who made 200+ FG this season, only two have an effectivness rating of less than 1.000 - Angel McCoughtry at 0.964 and Tina Charles at 0.954. McCoughtry is a volume shooter who takes some very difficult shots. Charles's FG% this year was 0.400, below the WNBA average and very atypical for Charles.
Do any of the above numbers prove anything? Maybe, maybe not. There's an old saying that 90 percent of success in life is just showing up. In the case of WNBA players, it could be that 90 percent of success in field goal shooting isn't just showing up - but where you show up.