2 seam vs. 4 seam, advice needed!

I’m a senior in high school and I’ll be in my team’s starting rotation this year. I am left-handed, and throw from a little higher than 3/4 arm slot (7/8? lol). I throw a 2 seam (84-87 mph), cutter (81-84), curve (71-74), and circle change (72-75). Since about age 10, I have always thrown 2 seams, never 4 seams, just as a matter of preference and because my 2 seams add even more to my natural lefty tail. I know that 4 seams go faster because of the ball’s more even rotation, airflow over the seams, etc. However, the 2 seam is already a swing through pitch for me, and I don’t know if the speed gained by throwing a 4 seam is significant enough to offset the loss of movement in comparison with the 2 seam. I’m not considering adopting the 4 seam entirely, just mixing it in when I really need some extra juice to blow it by a guy. Thoughts?

Pretty much what Tim Lincecum does. The 2-seam is primary, offset with the curve and change-up and an occasional 4-seam.

I used my 4 seam when I had to elevate or if I had to get in tight to a same handed hitter. I didn’t have to worry about it running in and hitting the batter like the 2 seam was more likely to do.

It would be beneficial to use both, as you progress up the ladder they will want you to have both in your repertoire. If your continually throwing a 2-seamer/sinker then hitters are going to gear up on it. Learn to use both and interchange them to both LHH and RHH