Foul shots

After writing later last week about a baseball article in the PD that strangely veered into the merits of underhanded free throws, I thought I should investigate that phenomenon a little deeper, and found this article in Discover from a couple years ago in favor of the granny shot. I don't think they make a particularly strong case.

Physics Proves It: Everyone Should Shoot Granny-Style
Shooting a basketball underhand gives your shot far better arc and spin.
by Curtis Rist
I gotta say, I'm a bit skeptical of the premise laid out in this subtitle. I'm always a little wary of people who advocate underhand shots anyway, because it seems like they're trying too hard to be quirky, counterculture, and contrarian. I mean, Rick Reilly did a piece in favor of it - that should give you an idea.

As a boy in Elizabeth, New Jersey, in the 1950s, basketball legend Rick Barry got some painful coaching lessons from his father, a semipro.
Of course Rick Barry is here. Everything positive ever written about granny shots references Barry, probably because he was the only good underhand free throw shooter in NBA history. This article is supposed to be about the science of underhanded free throws, so why fall back on the one anecdotal piece of information backing them? btw, the Cavs' Mark Price is the best foul shooter of all time, and he shot normal style.

Also, Barry's career FG% was .456 - as much bizarre enjoyment as people get from citing his underhand foul shooting as the sole reason for his success, the guy was really talented. No reason to suspect he wouldn't have been a fantastic standard foul shooter.

Judging by mechanics alone, just about every foul shot should be a winner. "There’s nothing simpler in basketball, because you can take all the time you want to make it, and there’s nobody waving his arms in front of you trying to block you," says Peter Brancazio, a physics professor emeritus from Brooklyn College and author of SportsScience: Physical Laws and Optimum Performance "I’m convinced that from a physics standpoint, if everyone learned to throw underhand you’d see these statistics rise dramatically,” Brancazio says.
Using the verb "throw" here makes me even more suspect.

The key to a successful foul shot lies in the arc of the ball — in general, the higher the better. While an official-size basket is 18 inches in diameter, the basketball itself is only about 9 1/2 inches, which gives a margin of 8 1/2 inches. But when the ball is thrown nearly straight at the basket, in the style of Shaq, the margin disappears because the rim of the basket, from the perspective of the ball, resembles a tight ellipse. "That’s why these guys miss so much," Brancazio says. "Because of the sharp angle of the typical overhand throw, there ends up being a much smaller window for the ball to go in."
"Shot." Please stop calling it a "throw."

If the ball comes down at the basket from a steeper angle, the way it does if tossed up in the high arc characteristic of an underhand throw, the margin reappears. "That means there’s a far greater chance of making the basket,” he says. Using lots of trigonometry, Brancazio calculated the optimal angle of the arc from the free throw line. If tossed at 32 degrees or less, the ball will most likely hit the back of the rim. "That doesn’t mean it won’t go in, but it will certainly bounce off the metal and reduce the chance of success," Brancazio says. At angles greater than that, the ball has a chance of making a nice swish. The optimum angle for the shot, he finds, is 45 degrees — plus half the angle from the top of the player’s hand to the rim. "The shorter you are, the steeper that angle has to get to give you the best chance of making the shot,"he says.
So why advocate an even lower release point?

Of course, lobbing a ball very high so that it comes down nearly straight into the basket would be the most efficient technique, but a shot like that "is almost impossible to aim," Brancazio says. Instead, he says, his formula makes it possible for a player to shoot with the largest possible margin for error.
I don't disagree with anything Brancazio has laid out here. However: what does this have to do with an underhand vs an overhand free throw? I fail to see why one couldn't achieve this optimum arc with a standard free throw just as easily as with a granny shot. This article, unfortunately, doesn't make that connection. It just explains the ideal shot arc, then declares the granny shot better.

Another reason why the granny shot helps a free thrower win cheers rather than jeers: It gives a backward spin to the ball. If a ball with backspin happens to hit the metal rim of the basket, the friction of contact suddenly reduces its forward velocity. “It’s like a drop shot in tennis. The ball bounces, but it doesn’t have a forward motion on it,” Brancazio says. This effect tends to freeze the ball at the rim and greatly increases the chance that it will tip into the basket rather than ricochet off.
Again: why is this an argument in favor of shooting underhanded? Proper release and rotation on an overhand shot gives the ball plenty of backspin. So far here, we've seen two factors in a successful free throw, neither of which is enhanced by an underhand shot, cited as evidence in favor of such a shot.

The underhand throw can also minimize the drift of the ball. "A little sideward nudge at the start of the throw will translate into a big movement toward the end," says Tom Steiger, a researcher who taught basketball physics at the University of Washington in Seattle.
True, regardless of the release point.

The trick to keeping the ball moving along a single plane toward the basket lies in "minimizing the sideways motion," he says. "In other words, you have to keep your elbows tucked in." If they are sticking out, that can easily add an unwanted nudge to the ball, which results in a missed shot.
Wow, I'm starting to bore myself. Good form from either variety of shot involves keeping one's elbows in and arms straight.

The underhand throw provides better stability than the overhand "because you’re holding the ball with both hands," Steiger says. This helps players balance the subtle motor muscles in the hands and keeps them more relaxed.
I hold my foul shots with both hands as well.

The movement of the underhand throw is a simple, easy-to-control upward pendulum motion. By contrast, the more conventional overhand free throw shot involves separate movements of the wrist, elbow, and shoulder that can add errors, Steiger says.
This, I can possibly buy. You may indeed be minimizing the number of moving parts with an underhand shot.

"If the ball ends up rolling off one side of your hand even a little bit, you’ll miss."
And we're quickly back to saying things that apply no matter how you shoot.

Despite the logic of a granny approach to foul shooting,
Eh, not convinced of this "logic" at all.

no NBA player has used it since Barry retired in 1980. "That baffles me," Barry says. "With the underhand shot, I could make 80 percent of my throws with my eyes closed. And I do mean closed." Over the years he has tried to convert everyone from four of his sons who have played professionally to Shaq to Chris Dudley—but nobody has paid any attention. "A lot of guys who are lousy at the free throw would be prime candidates for this, but they just won’t do it," says Barry, whom the NBA identified as one of the 50 Greatest Players in history in 1996. "I mean, how can guys call themselves professionals when they can’t even make 60 percent of their free throws? Where’s their sense of pride?"
Improvement on this front has more to do with simply practicing than switching over to Barry's goofy shooting style. One thing completely omitted from this post is the element of practice. Basketball spend endless hours practicing shooting, and pretty much every shot they take from the field is, of course, overhand. All of that practice translates to the foul line. If you're a granny shooter, however, you have to learn and develop an entirely different skill, and receive no mutual reinforcement when practicing the two disciplines.

Also, and I kinda saved this for the end: you look like a total nerd shooting granny style.