Every pitcher has their repertoire of pitches that makes him or her unique. Some pitchers throw a lot of junk or off-speed pitches. These are your curveballs, your sliders, and even your knuckleballs.
Then you have pitchers who just reel back and throw the ball as hard as they can in hopes of blowing the batter away and sending him back to the dugout wondering what just happened.
What many casual fans of baseball might not know is that these pitchers can actually throw multiple different types of fastballs. The two different types of traditional fastballs are the four-seamer and the two-seamer.
The Four-Seam Fastball Grip
The four-seam fastball grip has been a part of baseball for as long as baseball has existed.
Here you have the pitcher grab the baseball across all four seams and throw the ball from their traditional windup. This is often the fastest pitch a pitcher can throw.
In terms of movement, the four-seam fastball is traditionally a very straight pitch with no arc or side to side movement. With this pitch, you are using your strength against the batter’s strength in an effort to overpower them.
You will find many pitchers who throw the traditional four-seam fastball over 100 miles per hour on the Major League Baseball level.
On the opposite side, you will find some pitchers who throw more off-speed pitches will top their four-seam fastball out in the low to mid-eighties. These pitchers use their fastball as a way to keep batters honest and keep them on their back foot in the batter’s box.
The Two-Seam Fastball Grip
The 2 seam fastball grip is not used by every pitcher because of the movement the pitch has.
A two-seam fastball moves from left to right or right to left, and because of this movement, the pitch is typically five to seven miles per hour slower than the pitcher’s traditional four-seam fastball.
The pitch is held by the pitcher placing his or her index finger and middle fingers in between the two seams that run vertically up the baseball. When releasing the baseball, the pitcher can put more pressure on one of the two fingers, and the baseball will break in that direction.
If a pitcher places pressure on the index finger, the ball will run away from right-handed batters from a right-handed pitcher. If the pressure is placed on the middle finger, the ball will run away from left-handed batters.
Pitchers with the best two-seam fastball grip use them to break over the plate’s far side from the batter or start the pitch directly at the batter before having it break over the inside part of the plate.
Pitchers who can command the two-seam fastball and throw it for strikes can use it to create bad swings on their more traditional and straighter four-seam fastball.
The two-seam fastball is more likely to create bad swings on its own since Major League hitters can typically time a four-seam fastball regardless of speed.