# Compensating for CIT

#### LAMas

##### AzB Silver Member
Silver Member
"Collision Induced Throw (CIT)
When a ball contacts another ball at an angle, the second ball’s departure angle is deviated in the direction of the first ball’s motion. The amount of throw increases with cut angle and decreases with speed.
Tip: To counteract the effect of collision induced throw either (a) aim to over cut every shot relative to the tangent line or (b) use a touch of outside spin."

https://bullseyebilliards.net/blogs/articles/19575939-billiard-physics-ball-ball-contact

Geometry is perfect but only gets you close to the geometric cut angle because of CIT that causes a slight undercut when the CB arrives at the ghost ball and collides with the OB.

Can you compensate to get the OB on the geometrically correct line by pivoting to the outside of the center of the CB with fractional tip offsets to overcut/widen the angle and apply outside spin?

If so, how much?

##### AzB Silver Member
Silver Member
As much as you need.
More then you need.

It is up to you.

#### mikepage

##### AzB Silver Member
Silver Member
"Collision Induced Throw (CIT)
When a ball contacts another ball at an angle, the second ball’s departure angle is deviated in the direction of the first ball’s motion. The amount of throw increases with cut angle and decreases with speed.
Tip: To counteract the effect of collision induced throw either (a) aim to over cut every shot relative to the tangent line or (b) use a touch of outside spin."

https://bullseyebilliards.net/blogs/articles/19575939-billiard-physics-ball-ball-contact

Geometry is perfect but only gets you close to the geometric cut angle because of CIT that causes a slight undercut when the CB arrives at the ghost ball and collides with the OB.

Can you compensate to get the OB on the geometrically correct line by pivoting to the outside of the center of the CB with fractional tip offsets to overcut/widen the angle and apply outside spin?

If so, how much?

It is just an aim change, and I don't know why you would treat it differently than any other aim change.

Purposefully introducing/changing spin on the cueball for the purpose of effecting an aim change makes no sense to me.

#### ChrisinNC

##### AzB Silver Member
Silver Member
"Collision Induced Throw (CIT)
When a ball contacts another ball at an angle, the second ball’s departure angle is deviated in the direction of the first ball’s motion. The amount of throw increases with cut angle and decreases with speed.
Tip: To counteract the effect of collision induced throw either (a) aim to over cut every shot relative to the tangent line or (b) use a touch of outside spin."

https://bullseyebilliards.net/blogs/articles/19575939-billiard-physics-ball-ball-contact

Geometry is perfect but only gets you close to the geometric cut angle because of CIT that causes a slight undercut when the CB arrives at the ghost ball and collides with the OB.

Can you compensate to get the OB on the geometrically correct line by pivoting to the outside of the center of the CB with fractional tip offsets to overcut/widen the angle and apply outside spin?

If so, how much?
There is no simple solution, as in my opinion, CIT is not consistent and cannot be predicted. It is based on factors such as how fine and smooth the cloth is, the cleanliness of the cloth, and I'm guessing most importantly the cleanliness and newness of the CB and OB you are hitting. If you plan to combat CIT by overcutting cut shots or applying outside english on these shots, you will overcut many of those shots than you would have otherwise pocketed, in my opinion. It is just one of the elements in this game that will always be very hard to predict, and misses due to CIT occuring to various degrees will always happen.

#### 336Robin

##### Multiverse Operative
Gold Member
Silver Member
There is no simple solution, as in my opinion, CIT is not consistent and cannot be predicted. It is based on factors such as how fine and smooth the cloth is, the cleanliness of the cloth, and I'm guessing most importantly the cleanliness and newness of the CB and OB you are hitting. If you plan to combat CIT by overcutting cut shots or applying outside english on these shots, you will overcut many of those shots than you would have otherwise pocketed, in my opinion. It is just one of the elements in this game that will always be very hard to predict, and misses due to CIT occuring to various degrees will always happen.

I'll agree the adjustments due to aim point can get pretty subjective and its just as easy to hit some of those shots a touch harder scrubbing off the CIT which sounds stupid until you get on really dirty cloth or under damp conditions as I did about 3 yrs ago in a really bad place.

I think people forget to learn to play with the sliding cue ball as a way to get around the table in as much as a rolling one at times because of the relatively great condition of most tables in nice places these days.

Adding a tip of outside doesn't hurt but it might hurt your position at some point and you just have to choose.

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#### dr_dave

##### Instructional Author
Gold Member
Silver Member
It is just an aim change, and I don't know why you would treat it differently than any other aim change.
That's the easy part. The hard part is knowing how much to change the aim over a wide range of shot types. For those interested, I have a short summary of the important things one needs to know to do this at the bottom of the Adjusting Aim for Throw tutorial page.

Purposefully introducing/changing spin on the cueball for the purpose of effecting an aim change makes no sense to me.
... although, no aim change is required if using gearing outside english ... assuming outside english is appropriate for a given shot, one can accurately compensate for squirt and swerve, and one can accurately judge the gearing amount of english required for a given shot (e.g., using the 40% rule).

Regards,
Dave

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