Why striped ball for rotation?

A "12-6" or "11-5" throw.... at youth levels you'll never know the difference..... Actually, the spin of the ball and movement of the ball through air, causes the throw (ball) to move out of its orginal path (ie. BREAK)... (It is not a simple explanation and requires a lot of physics and math which I'll try to simplify....)

Actually, we also have to consider the Z axis...... (Per Bear's geometry). I like to use a catchers perpective (or recieving player). I like to refer to the Axis of spin of the ball....(IE earth Axis of spin extends thru the north and south poles) In baseball, you can see a small red circle or (dot) around one end of the axis of spin. (the seams rotating about the axis).

Now if we have a true 12-6 or 11-5 spind you should not see the ends of the axis (or red circles or dots)...( they should be pointing perpendicular to your sight... out the sides of the ball). It has been my expereince, that this almost never happens in youth ball. Almost every time you can see one end of the axis (red dot or circle) pointing somewhat forward....

Now movement of the ball is caused by the spin of the seams, the effect of air resistance, the Bernoulli effect, and other physics laws. .... Simple "RULE OF THUMB"... The ball will break in the direction of spin of the ball as seen from the catcher.... IE 4 seam fast ball...(What I assuming you call 12-6 .... actually 6 to 12 as seen from C) will "break up" (don't post about FB not going up... It takes to long too explain)

Now take a Curve ball..... 12 to 6 (as seen from C) it will break down. Now if there is a tilt to the axis 11-5 it will break down and toward the 5 (slight left to right movement for RH). A 10-4 will move less down and more L to R.

Now consider the axis, not prependicular to the catcher.... The ball will still break in the direction of the spin of the ball.... So you get differing breaks...by changing the axis of spin and the rate of spin or ratation.

Now as Bear said you want a 12-6 (6-12 in my viewpoint definition) for position players... This ball "breaks" the least of any... Ie. it is the Straightest... (why? the force which casues the break is upward and it fights against gravity. So you slightly counteract gravity which makes a straighter throw)...plus it does not move L to R.

Now, change that axis in any direction and you cause a lateral force and movement.... So pitchers like 11-5 (5-11) 10-4 and even want to move the axis in the Z-plane... Pointing slightly in front...

Learn to control this and you can earn what Greg Maddux does....

So final answer.... 12-6 shouldn't have any L to R movement. 11-5 will have some L to R movement and 10-4 will have more L-R movement.... Etc Etc....