Saturday, November 28, 2009

Dunking and Vertical Leaping Ability in Men and Women

A recent blog entry from a company that seems to want to sell information about how to increase your vertical leap provides some data. The quotes are from an article from David Patterson and D. Fred Peterson in Measurement in Physical Education and Exercise Science.

I'll list the 5th percentile number (the number where 95 percent of subjects exceed the value), the mean number (or average value) and the 95th percentile for both sexes:

Men: 16.5 inches/22.1 inches/28 inches
Women: 10 inches/14.1 inches/19 inches

Note the difference between the 5th percentile for men and the 95 percentile for women. This means that a man who is pretty much in average shape - not overweight but not a trained athlete - can outleap the woman at the 95th percentile value.

It seems that with Britney Griner now becoming a sensation, the haters are moving the goalpost once again.

Initial argument: "Women's basketball sucks because women can't dunk."
Newer argument: "Women's basketball sucks because the women who can dunk can't dunk like men."
Post-Griner argument (brand new): "So Britney Griner throws down? Big deal. She's 6'8" tall. She should be able to dunk."

(I always respond with my "Playboy Dunkers" argument - if everyone in the WNBA looked like a Playboy model and dunked like Superman on crack, the haters would still hate women's basketball. Their hatred isn't based in rationality, but in reactionary jerkitude.)

Let's examine the average NBA player vs. the average WNBA player. The average NBA player is probably around 6'8" tall. The average WNBA player is about 6 feet or 6'1".

The height of a rim above the court is 10 feet. A 6'8" player might have arms which are about 2'6" long - maybe longer, as basketball is a sport in which a larger reach is more advantageous. (All human proportion figures are from this website, with extrapolation.) Let's assume that with his arms fully extended, his middle index finger might extend to 9'3" above the floor. Add the diameter of a basketball ball - about 10 inches - and he needs a 19 inch vertical leap to get at least close to dunking. Lucky that most relatively athletic men should have a vertical leap of 19 inches. If he has long arms, it becomes that much easier.

Let's look at the 6'1" woman. Her arms are about 2'3" long. With her arms fully extended, her index finger might reach to eight feet above the floor. Add the missing two feet and 10 inches, and she needs to be able to jump about 36 inches to dunk - a leap which is fairly routine for some men, who might have vertical leaps exceeding 36 inches, but which would be a ludicrous vertical leap for a woman - theoretically impossible, in fact.

As a matter of fact, let's go back to the case of Britney Griner. At 6'8", she also needs to jump about 19 inches in order to dunk. Even for an athletic woman, 19 inches is a very difficult leap, a leaping distance limited only to women which are very fit. Which means that we should expect a few dunks from Britney, but not very many. Still, it's a lot more than the zero dunks you can expect from her shorter competitors.

As a matter of fact, not every 6'8" basketball player has dunked.

Maria Stepanova, Haixia Zheng, Razija Brcaninovic, Rhonda Smith, Margo Dydek, Lindsey Taylor, Katie Mattera are the only WNBA players I know in WNBA history who were 6'8" or taller. None of them ever dunked. Dydek could have dunked - she was 7'2" tall, for goodness sake - but chose not to, undoubtedly out of fear of hurting herself. (She also seems to have a vertical leap of five inches.)

Lisa Leslie dunked at 6'5". Candace Parker dunked at 6'4". They are the only players ever to dunk in a WNBA regular season game. A 6'6" Sylvia Fowles dunked - on the second try - with everyone agreeing to get out of the way - in the 2009 WNBA All-Star game, an extremely unimpressive dunk. Michelle Snow, who is 6'5", dunked while she was a player in Tennessee but never in the WNBA.

So Griner's extra three inches of height above Lisa Leslie not only gives her a major advantage. Furthermore, less than one percent of all the women who have played in the WNBA have been 6'8' or over - and only one of those was over seven feet tall. Compare that with the NBA. Add the numbers on vertical leap and you'll see that a dunk is going to be an example of exceptional athleticism in the WNBA - but something so pedestrian in the NBA that the dunkers have to try to add degree of difficulty just to keep it interesting. The haters won't get it, but anyone with knowledge of how the odds are stacked against female dunkers will be damned impressed.


Rebecca said...

Addendum to dunking notes: Dydek did dunk in All-Star practice one year, as did Sylvia Fowles. Michele VanGorp, who's 6'6", dunked in shootaround in 1999 with the Liberty. I keep thinking Michelle Snow dunked during All-Star practice one year, too, but I might just be going crazy.

Excellent stats, though they won't penetrate the skulls of the idjits.

Patrick said...

Snow dunked in the All Star Game at the end of the 4th quarter on her second attempt two years ago (2007) when it was at MSG. That was the year Diana made a laughable attempt and Tweety made a number of admirable but failed attempts.

Anonymous said...

Thank you for the real stats... as a former D1 player... way back in the day, I spent my BBall life trying to dunk.I was listed at 6 feet (i'm just an eigth under) and all during my college years I would get stuck on the rim! I could grab the rim and pull up to dunk, but that can hardly be used in a game! There was a 6'8" girl at South Carolina State that spent our warm up time DUNKING all through the lay up lines!! Women play Ball and If they want the game to look the same as the Men's.... Here comes the HERESY!! They should lower the rim by 5 or 6 inches! They already shrank(is that even a word?LOL) the ball... So why not?
BBall Lifer #BBallGurlzRock