(49 short days until game #1)
Today was a very eventful day in the baseball world. Spring training started and Hannah and Derek Jeter announced the birth of their first child. To celebrate both, I thought I would break down the physics behind two of Derek Jeter's most iconic defensive plays.
The first play, commonly called the "jump-throw" is known across the world by almost any baseball player or fan. It starts with a sharply hit ground ball towards the hole between Jeter and third base. Looking at simple kinematics- based relationships, it is a large feat in itself for Jeter to be able to intercept that ball by moving as far and as fast as he did. Next, he calculated the exact flight of the ball as it hopped into his glove, and then with the full momentum of his body taking him away from first base, unleashed a powerful, incredibly accurate throw that beat the runner and ended the inning. Critics say that the only reason that play was made was because Jeter didn't have the speed to get to balls hit away from him, but nobody can deny the fact that the throw, made perfectly, despite the fact he was traveling at a constant speed away from his target and being accelerated back to earth by gravity, is one of the greatest of all time.
Another iconic Jeter play, made in a pivotal playoff game against the Oakland A's shows just how good of a physicist Jeter was. The play began as a defensive error by the right fielder. He made an awful throw trying to get the tying run out at the plate. He missed the 1st baseman who was supposed to relay the throw home, and instead sent it sailing into the grass by the 1st base dugout. All of the sudden, Derek Jeter came streaking across the field, and on a full sprint fielded and backhand flipped the ball to the cathcer, Jorge Posada, who nailed Giambi with a quick swipe tag to preserve a 1-0 Yankees lead. The physics come in when Jeter released the ball. Travelling at over 15 mph, Jeter knew exactly what vertical and horizontal angle to launch the ball at in order for it to be delivered to Posada to enable a smooth tag. In the video, one can clearly see how the ball seems to curve as it is being delivered to Posada. This is because the ball is moving in all 3 directions at once. It is moving forward with the force of Jeter's "push", sideways with the constant velocity supplied by the sprinting body, and downwards due to gravity. By correctly judging all three of these factors and many more, Derek Jeter was once again able to make himself into baseball legend with the flash of his glove and the flick of his wrist.
Here is a video of some of Jeter's best defensive plays. It starts off with The Flip and his Jump-throw is at 2:44.