If you grip the baseball with your fingers across the wide part of the seam so that both your index and middle fingers are touching two seams, you throw a straight pitch called a "four-seam fastball." This pitch moves very little and is often used when a pitcher really needs to throw a strike.
A two-seam fastball or “sinker" is thrown by gripping the baseball across the narrow part of the seam so that both your index and middle fingers are along a seam. Sinkers are harder to throw, but the movement they cause can make them harder to hit.
A cut fastball or “cutter" is thrown by using the same grip as a four-seam fastball. Instead of the usual grip, though, a pitcher holds the baseball off-center. This pitch deceives batters when it moves slightly as it reaches the plate.
Some batters believe in a mythical pitch known as a "rising fastball." We assure you, though, rising fastballs fall into the same category as unicorns and the Loch Ness Monster.
When pitchers throw fastballs, they put backspin on the baseball. A scientific phenomenon — called the "Magnus effect" — creates an upward force on the baseball, which makes it fall slower than expected.
But gravity does rule the day, and fastballs do indeed fall — not rise — from the time they leave the pitcher's hand until they hit the catcher's mitt.
If a pitcher switches from a two-seam fastball to a four-seam fastball, the batter expects a slower pitch. When the baseball arrives faster at a higher level (due to the increased backspin on the baseball when thrown faster), the baseball appears to rise.
Scientists would tell you that the Magnus effect can overcome gravity, so a rising fastball is theoretically possible. However, those same scientists have shown that the amount of backspin that would be required is beyond the capabilities of the human arm.
So exactly how fast is a fastball? There's no set speed required to equal a fastball. It's simply a type of pitch that results from a pitcher throwing the baseball as hard and as fast as possible.
For years, the best baseball pitchers in the major leagues strived to reach the 100 miles per hour (mph) mark for a fastball. Nolan Ryan held the world record for a time with a 100.9 mph fastball thrown in 1974. Today, it's quite common for major league pitchers routinely to throw fastballs in the 95+ mph range.
In September 2010, a fastball thrown by the Cincinnati Reds' Aroldis Chapman was measured at 105.1 mph. Unofficially, Bob Feller claimed that a fastball of his was once measured at 107.9 mph way back in 1946.
Pitchers do seem to be pitching faster as time goes on. In the last 10 years, at least 20 different pitchers have thrown fastballs that have been measured at over 101 mph!