2-seam vs 4-seam fastball

[sluggers]

Do you think the greater surface area and raised seams of a 12 inch softball would make a difference in the study results?

Nope.

(Geez...I learn all kinds of neat stuff on this forum. I had no idea that an NCAA baseball was different than an MLB baseball.)

Of course, the diameter of a softball does not change from 2-seam to 4-seam. So, the only difference in movement would be that caused by the seam height.

Turns out that the seam height to diameter ratio for a 12 inch NCAA softball is *less* than for an NCAA baseball. (In affect, the seams on an NCAA baseball are higher relative to the size of the ball than an NCAA softball. Surprisingly, the NCAA softball is closer to the MLB baseball. So, it is easier for the guy over at the college baseball field to curve the ball than the gal over at the college softball field.)

The test was on a spinning NCAA baseball in a 2-seam and 4-seam orientation. There was no difference in drag coefficient. (If you want to read the sordid details: Dissertaion on drag coefficient of sports balls)

Therefore, a softball won't be affected by seam orientation of a spinning ball either.

 

[brethobson]

it would have been nice to have a study focused on just softball. like most studies this one is flawed and you can make the data support most arguments. to assume a baseball and softball will react similar is not physically possible. diameter always has importance. i would have liked to see the softballs actually rotate 12/6 with 2 vs 4 seems. not just stating that the author couldn't rotate the balls as they wouldnt fit in the machine. also they used a mens slow pitch with flat seems and not the traditional high seem softball. this in itself creates the softball argument null.

 

[Classof2020]

I am so curious about this discussion still. I like studies and facts that seem solid. But I'm still wondering. My DD, and her coach are RH, and her PC has taught her to throw both 2 & 4 seam FBs. The PC played college ball and is an experienced pitcher who originally taught her that the 4 seam is more controllable. And that the 2 seam was slightly slower with a break to the outside. So now I am wondering is this just what she experienced as a pitcher and has then passed this expectation on to my daughter. So since she THINKS it's going to end up outside, she subconsciously sends it to the outside?? Anybody else throw both and have this experience?

 

[CoachFP]

Nope.

(Geez...I learn all kinds of neat stuff on this forum. I had no idea that an NCAA baseball was different than an MLB baseball.)

Of course, the diameter of a softball does not change from 2-seam to 4-seam. So, the only difference in movement would be that caused by the seam height.

Turns out that the seam height to diameter ratio for a 12 inch NCAA softball is *less* than for an NCAA baseball. (In affect, the seams on an NCAA baseball are higher relative to the size of the ball than an NCAA softball. Surprisingly, the NCAA softball is closer to the MLB baseball. So, it is easier for the guy over at the college baseball field to curve the ball than the gal over at the college softball field.)

The test was on a spinning NCAA baseball in a 2-seam and 4-seam orientation. There was no difference in drag coefficient. (If you want to read the sordid details: Dissertaion on drag coefficient of sports balls)

Therefore, a softball won't be affected by seam orientation of a spinning ball either.

Hey Sluggers, the softball is at least a third less dense than a baseball which in my opinion has to be taken into consideration for ball movement relative to seam height etc.

 

[Carty]

In the dissertation, there was an difference in the reynolds number, and a reduction in the drag crisis for difference in balls wigth rough surfaces, or raised seams. Also, the orientation of the seams and height of the stitiches had an effect on the lift of the ball.

 

[RubberBiscuit]

Very interesting article Sluggers but I conclude it as inconclusive (in reference to any proof a 2 vs 4 seam fb have the same flight path)

Why -

I think the report is better at concluding that the Coeff. of Drag is more "equal" between the two fb types than Lift.

I think the magical "missing" link here in this report is exactly what they sort of opened the door to themselves in their conclusion - "Lift & Drag are sensitive to seam height and orientation which is difficult to control experiementally".

I think the secret sauce here could be the orientation (since seam height is constant between pitch-to-pitch with the same ball) of the 2 vs 4 seam fb which COULD have a dramatic difference in the critical zone of the boundary layers.

I would LOVE to see a more controlled experiement where they lock down the orientation factor here instead of it being an unknown variable.

 

[Amy in AZ.]

Oh, geez. I had a dad bring me his princess, a few years back. She was 12. He thought she was the next Jenny Finch. I worked with her awhile and I determined that she was very illegal on every pitch. She was hopping at least 12 inches. So, her dad and grandpa weren't too happy that
I wasn't just thrilled with the little girl. Then, the dad said "Show her your 2 seamer." I had to just nod and smile.

The only reason I would have a little girl grip "the narrows", is if her hand is really small.

 

[RubberBiscuit]

Very interesting article Sluggers but I conclude it as inconclusive (in reference to any proof a 2 vs 4 seam fb have the same flight path)

Why -

I think the report is better at concluding that the Coeff. of Drag is more "equal" between the two fb types than Lift.

I think the magical "missing" link here in this report is exactly what they sort of opened the door to themselves in their conclusion - "Lift & Drag are sensitive to seam height and orientation which is difficult to control experiementally".

I think the secret sauce here could be the orientation (since seam height is constant between pitch-to-pitch with the same ball) of the 2 vs 4 seam fb which COULD have a dramatic difference in the critical zone of the boundary layers.

I would LOVE to see a more controlled experiement where they lock down the orientation factor here instead of it being an unknown variable.

Oh and my non-technical response here is that my DD does show a difference between the two pitches. The 4 -seam drops more, is a touch slower, but is more consistent in its flight path.

 

[samalusa]

My 10 year old going on 11 next week, DD throws both. Four seam to overpower and two seam is more of a finesse (a little slower) fast ball that does drop off the outside corner. Sometimes she doesn't have a good feel for the four seam. The two seam and change-up gets her by until she "finds" the four seam.

 

[undergroundga]

Now I know why they announce hertz rates on tvs, cool!
As for the 2 seam vs the 4 seam, My dd has never thrown a 2 seamer. She has always thrown everything using 4 seams. Never even learned to throw with 2 seams. She could prolly do if someone showed her the grip, but I don't think any one ever has. Early on one of the key points I picked up was that spinning the ball was very important. So we talk a lot about spinning the ball. To me it's a grip issue. In order to spin the ball faster she needs to have a better grip and in "my" mind she can grip a 4 seamer better then a 2, in effect spinning the ball better.