Dynamics of the 2 and 4 Seam Fastballs

To many, gripping a baseball is pretty elementary stuff. But without a proper and consistent grip for his pitches, a pitcher will struggle to command the baseball. Since the fastball is usually thrown 60-75% of the time over the course of a pitcher's start, good luck if you lack command of it.

In this segment, I will cover the basics of throwing both 2 and a 4-seam fastballs.

The 4-seam fastball will be a pitcher's straightest and fastest pitch. It gets its name from the fact that. when thrown, the 2 "horseshoes" on the baseball spin so that the 4 seams rotate end-over-end. This causes the baseball to cut through the air with as little resistance as possible; thus, it is the most aerodynamic.

You will notice in the picture to the left that the index and middle fingers cross over the horseshoe (any horseshoe) on the ball. To maximize velocity, keep these two fingers as close together as possible while maintaining control of the pitch. Conversely, to throw a slower fast ball, spread these fingers further apart.

You will notice in the second picture that the thumb sits directly underneath the baseball. A good rule of thumb (Really, that phrase was unintentional.) is that your thumb and middle finger should split the baseball into two "hemispheres". This will increase your command on the pitch by preventing any inconsistent and unwanted cut or sink on the baseball.


Sidenote: This is also the grip that a shortstop will use throwing the ball to first base or an outfielder would use to throw a runner out at the plate. Like I said, this is the straightest, fastest, and most accurate grip.

The 2-seam fastball is a common variation of the 4-seam fastball. To grip it, a person simply places their index and middle fingers between what I was taught as "the railroad tracks" of the baseball. You could also describe it as between the seams and on the "league label". Your thumb will be placed underneath the baseball. More specifically, it should be underneath the ball so that it splits the ball with your middle finger. To repeat, a pitcher increases his ability to command his pitch by splitting the ball with his thumb and middle finger.

Now that you have gripped the 2-seamer, it is important to know its purpose. The purpose of a 2-seam fastball is to maintain almost as much velocity as a 4-seam fastball while increasing or maximizing the amount of arm-side movement.

If you have the ability to command a consistent 2-seam fastball, I would suggest working off of that pitch. You can still implement your 4-seam fastball in counts when you need a little more "gitty-up" (0-2 climb the ladder).

The most important factor in deciding on which of the two fastballs to throw is your feel and command. You could be the hardest thrower since Nuke LaLoosh; but, if you can't get ahead 0-1 and command your 4-seamer, you will struggle.

And the same thing for the 2-seam: If you have nasty sink over the middle of the plate, you're going to get crushed.

As a result, the key is figuring out which of these two fastballs you have the best feel for and working off of it.

A general rule (over the course of a starting pitcher's start) is that a pitcher wants to throw roughly 60% fastballs, 20% breaking balls, and 20% change-ups. This being said, it is vital to have and maintain fastball command. It starts with the grip and finishes with executing the pitch by repeating your delivery/release point.

Note: To take it a step further, there is much debate among pitching coaches as to which side of the rubber a 4-seam pitcher and 2-seam pitcher should stand on. The general consensus is that a 4-seam pitcher should stand on the arm side of the rubber, and a 2-seam pitcher should stand on the glove side of the rubber. The idea is that a straighter/harder fastball (4-seam) benefits from having a greater angle; while the 2-seam pitcher benefits from a straighter line to the plate to allow more room for the sink to take place. I generally agree with this stance. However, there are always exceptions; and, it is important for each individual pitcher to "feel out" both sides (and the middle) of the rubber and decide for himself where he is more comfortable

The intent of the image below is to demonstrate the differences in flight path between the 2 and 4-seam fastball, as well as the effect of pitching from the first/third base side of the rubber and the variance of angles.

The "red" lines depict a 4-seam fastball and the "blue" lines depict a 2-seam fastball.

Also, both images simulate a right-handed pitcher.