A "
riser" is a type of
pitch in
baseball,
softball, and
wiffle ball which rises suddenly as it approaches
the plate.
In baseball, it is actually impossible to throw a riser using the traditional overhand pitching motion, because the action of air resistance on the low seams of a baseball is not powerful enough to produce a rising effect. The so-called "rising fastball" sometimes appears to achieve this effect, but is actually an optical illusion. It is only possible to throw a riser with a baseball if an underhand motion, such as that used by a submariner, is employed, and even then, achieving such an effect is extremely difficult due to the speed required.
The riser is much more common in fastpitch softball, which exclusively uses an underhand motion. Compared to a baseball, softballs are bigger, lighter, and have seams that are more raised, making it much easier to induce a rising action. Even so, throwing a riser in softball requires tremendous speed and backspin.
The riser is perhaps most common in wiffle ball contests, because the design and structure of a wiffle ball makes it easy to throw a riser from a variety of windups, including overhand and sidearm.