Riseball

A riseball or dimple is a pitch thrown by a pitcher in fastpitch softball. Upon release by the pitcher, the ball has backspin. The backspin and velocity are two of the factors that cause the ball to rise. Ihe name suggests that it curves upward. In fact, a well thrown riseball will look like it travels about half way to the plate and bounces off something in mid air changing the angle of its trajectory. A well thrown riseball continues on that trajectory over the plate. Weaker riseballs will fall or flatten out as they approach the plate. A very few pitchers can make a rise ball hop twice, once about half way and again right in front of the plate. By level of difficulty, the easiest riseball starts at or above the strike zone and ends well out of the strike zone. The mid rise will start in the lower part of the zone and will cross the plate in the top of the zone. The hardest to throw is the low rise which starts below the knees of the batter and moves up crossing the plate in the middle to lower part of the strike zone. There is a second type of Riseball, sometimes called a corkscrew rise. It is thrown with axial rotation. It spins like a bullet with an upward tilt of about 15 or more degrees. Unlike the a well thrown classic rise, this pitch will skip or hop like the normal rise, but will flatten out as it approaches the plate. The result of this pitch is more often a miss hit or popped up ball. Many people maintain that baseball does not have a rise ball as a small ball thrown overhand can not be thrown fast enough or with enough spin to defy gravity and rise, but merely fall slower. However, there has been much discussion about this and the necessary physical processes. Considering Fastpitch riseball hop and do not curve upward, Magnus calculations do not capture the nature of that movement. Magnus forces assume a continuous change of movement while the riseball acts as if the low leading pressure on the ball builds to the point where the ball is unable to move forward in a straight line and bounces upward. Again a riseball is not an upside down drop, but a ball that abruptly changes direction.

Jennie Finch is famous for striking out Major League Baseball players with this pitch.