Well now, there is a study on throwing a ball at a basketball hoop that says what I've been thinking - that throwing underhanded, or "granny style", increases the likelihood of the ball going into the basket, than throwing it overhand.
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.” 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.
Told ya! :)
Still, I don't think any basketball player, especially the professional, and the coaches, will pay much attention to this. But wouldn't it be interesting if someone actually does?