A two-seam fastball is a pitch in baseball and softball. It is a variant of the straight fastball. The pitch has the speed of a fastball and can also include late-breaking action caused by varying the pressure of the index and middle fingers on the ball.

What is the difference between a 2 seam and 4 seam fastball?

The Basic Difference Between 2 Seam and 4 Seam Fastball

The 4 seam should head straight to the plate, with very little movement but high speed. The 2 seam can veer slightly to the left for a right-handed pitcher and to the right for left handed players.

Is a 2 seamer the same as a sinker?

If the pitch moves more horizontally -- and it'll be in the "tailing" direction, running from left to right for a right-handed pitcher or right to left for a left-handed pitcher -- then it's a two-seamer. If the pitch has more vertical drop, it's a sinker.