Does the amount of gearing outside english vary with draw/follow?

[Not Dead Ted]

Have scanned the technical proofs, but unable to determine whether the amount of outside english needed for gearing effect is the same (or different) when using draw or follow. The amount of throw is reduced by positive or negative roll (draw/follow), does this reduce the amount of outside english to create a no-throw situation?

For example: 30 degree cut shot, no draw/follow, use 6 mm outside gearing english to eliminate throw. Now shooting with draw or follow: Still 6 mm outside english needed for gearing, or less?

 

[bbb]

you may want to pm dr dave for the answer
or post in the instructor section

 

[Patrick Johnson]

you may want to pm dr dave for the answer
or post in the instructor section

See the Good Doctor's detailed info about gearing english and top/bottom spin, etc. here:

Gearing Outside Spin - Dr. Dave Pool Info

Answers to frequently-asked questions about outside english and gearing in pool and billiards.

drdavepoolinfo.com

Sounds like you know most of this stuff, but for general info...

My pic below (also shown on Dr. Dave's page) shows how the "perpendicular offset" point on the CB is used to determine the tip/CB contact point to produce gearing english. We tend to think of gearing english as applying only to CB/OB contact, but as the pic suggests, gearing english can also be effective when contacting a rail (to produce "neutral running english").

pj
chgo

("perpendicular offset" = the point on the CB opposite the point that will contact the ball/rail)

 

[Bob Jewett]

Have scanned the technical proofs, but unable to determine whether the amount of outside english needed for gearing effect is the same (or different) when using draw or follow. The amount of throw is reduced by positive or negative roll (draw/follow), does this reduce the amount of outside english to create a no-throw situation?

For example: 30 degree cut shot, no draw/follow, use 6 mm outside gearing english to eliminate throw. Now shooting with draw or follow: Still 6 mm outside english needed for gearing, or less?

How far is the cue ball from the object ball, and how hard are you shooting?

 

[Not Dead Ted]

How far is the cue ball from the object ball, and how hard are you shooting?

Mostly concerned with banks off the long rail, so the CB-OB distance is almost always less then 3.5 diamonds.
I regard the CB speed I use as moderate, but the degree of rail pushback that I get with varying cushion incident angle corresponds very closely to what Jack Koehler terms as "hard." So probably a bit on the firm side.

When hitting centerball I get good results with backhand gearing english. Trying to explore if the amount of gearing english with draw or follow needs to modified. Since draw and follow minimize collision induced throw, does that mean the gearing english should be lessened?

 

[Bob Jewett]

The reason I asked is that when you use draw along with the sidespin, the effective amount of sidespin increases during each inch of cue ball travel to the object ball. That continues until the cue ball starts rolling smoothly or it hits the object ball.

With follow and side, on the other hand, that spin multiplying effect is much less, as the cue ball is rolling smoothly much sooner.

 

[Not Dead Ted]

The reason I asked is that when you use draw along with the sidespin, the effective amount of sidespin increases during each inch of cue ball travel to the object ball. That continues until the cue ball starts rolling smoothly or it hits the object ball.

With follow and side, on the other hand, that spin multiplying effect is much less, as the cue ball is rolling smoothly much sooner.

That is good to know. I'll go to the table and work with this.

 

[Bob Jewett]

That is good to know. I'll go to the table and work with this.

A good way to see if you have the cancellation correct is to use a stripe as the object ball and "point" the stripe in the direction of the shot. The stripe should roll like a tire and not wobble if you hit with gearing outside spin.