IR vs Bullet

[corlay]

IR spin, is it over the top spin or under spin?

Textbook "learning IR spin" is 6-12 or 1-7 top spin, tilted slightly inward to a right handed batter.

But, IR is not a determinate of spin direction or axis.
IR is a progressive series of linked biomechanical movements that a pitcher makes when delivering the ball.
IR is utilized in every pitch, even a change up. (the pitcher generally performs the IR sequences early on this pitch so the "whip" happens before, rather than at, release...)

 

[Man10]

Textbook "learning IR spin" is 6-12 or 1-7 top spin, tilted slightly inward to a right handed batter.

But, IR is not a determinate of spin direction or axis.
IR is a progressive series of linked biomechanical movements that a pitcher makes when delivering the ball.
IR is utilized in every pitch, even a change up. (the pitcher generally performs the IR sequences early on this pitch so the "whip" happens before, rather than at, release...)

Got ya. I began thinking about IR after reading the IR thread. I see the drills to teach IR but I'm still a little foggy on all those movements you mentioned.

 

[sluggers]

Man10,

"IR" unfortunately can refer to two different things.

(a) "IR" can refer to the pronation of the forearm before, during and after release.
(b) "IR" can also refer to the pitching motion from 12 to follow through The pronation of the arm is then a part of the IR motion.

You sometimes have to "read between the lines" to understand whether a poster is talking about just the forearm pronation or the entire IR motion.

 

[Man10]

I wish I understood IR better. I've been trying it myself and I'm must not be getting it so I know I can't teach it to her. Really wish there was an IR teacher close to us.

 

[JJsqueeze]

I wish I understood IR better. I've been trying it myself and I'm must not be getting it so I know I can't teach it to her. Really wish there was an IR teacher close to us.

it helps if you understand that IR is not a pitching style, it is just a term used to refer to a body part rotating towards the body and not away from it. You can IR a leg, a hand, a foot etc. It just happens to be a really succinct way of describing the singular action in pitching that differentiates what good pitchers do vs. what is commonly taught. It is really simple, if you pull a ball down the back of the circle and can throw it in the forward direction then your arm has performed what is called IR on this board. If you stand sideways with your arms sticking out from your body in that pose that Da Vinci made famous when analyzing the ratio of human body parts with your palms up and just let them fall with gravity then your arms with internally rotate in a way that mimics the correct pitching motion. it is not a secret or a high faluttin' concept.

 

[corlay]

to elaborate: "IR" as its used on this forum, refers to the delay of internal rotation of the humerus.

this is exemplified, most obviously, by a palm-up arm/hand/ball position at 9:00 (when arm is directly behind the pitcher during the delivery motion, parallel to the ground plane)

as Sluggers has stated, the pronation of the forearm, just before, at, and after release of the ball, is a movement that is timed, or coupled, to overlap with the end phase of the internal rotation and deceleration of the humerus, combined with some degree of flexion at the elbow, which is the "whip" we all refer to.

to throw a ball underhand, with an arm circle motion, you simply must internally rotate your humerus to do so. the key is when this happens. the "hellow elbow" or "HE" technique, which is most predominantly taught, encourages *early* rahter than *delayed* internal rotation of the humerus.

Delaying internal rotation of the humerus is advantageous because it creates "muscle stretch"' allowing an acceleration of the linked lever's (arm) most distal part (hand) right at and through the release phase of the pitch. This is a "pull and whip" movement.

Early internal rotation (pre-9:00) resluts in a pushing or "bowling" movement, which is biomechanically slower.

 

[Ken B]

I really like the descriptions above. One thing I like to stress is that whipping can feel a little out of control at first. Muscling, aim, bowling, HEing, etc., feels like you're doing something. With whip, the ball kinda explodes out of the hand instead of being thrown deliberately. The hyper focus on control is a whip robber and must be deemphasized at first. Once a kid can trust pulling the ball down in a lagged (palm up) position and allow the whip to happen--that's when the magic begins. Add some brush, drive and posture and you've got the foundation. It's the trust of the form that most struggle with because it's so counter-intuitive for kids, coaches and parents.

 

[Man10]

to elaborate: "IR" as its used on this forum, refers to the delay of internal rotation of the humerus.

this is exemplified, most obviously, by a palm-up arm/hand/ball position at 9:00 (when arm is directly behind the pitcher during the delivery motion, parallel to the ground plane)

as Sluggers has stated, the pronation of the forearm, just before, at, and after release of the ball, is a movement that is timed, or coupled, to overlap with the end phase of the internal rotation and deceleration of the humerus, combined with some degree of flexion at the elbow, which is the "whip" we all refer to.

to throw a ball underhand, with an arm circle motion, you simply must internally rotate your humerus to do so. the key is when this happens. the "hellow elbow" or "HE" technique, which is most predominantly taught, encourages *early* rahter than *delayed* internal rotation of the humerus.

Delaying internal rotation of the humerus is advantageous because it creates "muscle stretch"' allowing an acceleration of the linked lever's (arm) most distal part (hand) right at and through the release phase of the pitch. This is a "pull and whip" movement.

Early internal rotation (pre-9:00) resluts in a pushing or "bowling" movement, which is biomechanically slower.

This helps a lot. internal rotation happens but it's best to happen just before release, if I'm reading this right.
If I video her in slo mo what would be the check points to see if she is catching the whip and throwing correctly?

 

[corlay]

1. ball facing forward at 12:00, slight bend in elbow
2. ball facing up at 9:00, slight bend in elbow
(note: checkpoints 3-5 happen very quickly and in overlapped succession)
3. upper arm stabilizes and decelerates when at 6:00. IR of upper arm is occuring.
4. due to slight bend in elbow, lower arm lags behind upper arm
5. lower arm "whips" past stabilized upper arm. Pronation of forearm is occuring. elbow joint straightens somewhat as lower arm reaches 6:00 position and ball release.
6. total pronation of forearm generally occurs after ball is released, and upper arm continues forward after lower arm whips past it.

 

[Man10]

I think the biggest thing she lacks in the list you mentioned is the ball forward at 12 and the palm up at 9. She shows the third base side the ball at those two spots. How do those two positions help IR? Obviously they do, just asking to try to add understanding. Also what would be the drawbacks of her not having those positions? Are there indicators such as missing right or left, etc that tells me her hand isn't in those positions?