Ball hit with speed need to be over cut a bit more??

[Gatz]

This seems like a weird question, but it seems like when I have to force a ball into a pocket I automatically over cut it a bit. I don't even understand why I do this, but I do.

Does the object ball skid/slide more when it is struck harder? Is this the reason why you would have to over cut it a bit more than usual?

I find this is even more obvious with just a below centre hit. With a top spin stroke, with the same speed, it seems that I don't have to over cut it as much. What would be the reasons for this, if any.

 

[theUBC]

jump effect on hard shots

Hi
every time you hit the cueball hard it jumps (even several times-each time a little less just like a flat stone jumps on the water when you throw it). You can proove this when you put a dime on the table about 2 to 3 feet away from the cueball and then try to shoot the cueball hard in direction of the dime-you will see that the cueball will hop over the dime. You don't even have to raise the butt of your cue much...This means that the cueball will make contact with the objectball while the aquator of the cueball is higher than the aquator of the objectball. For this reason the objectball is cut more than wanted (a balls diameter is the the biggest at the aquator - and gets obviously slimmer above the aquator) For this reason those hard cut shots are often overcut or the cueball often scratches in the side pocket on the break although you aimed on the nose of the one ball. Even the slightest angle off to the sidepocket is widened by this "jump effect".
Hope that helps.

EKKES

 

[theUBC]

on the other hand, if you don't shoot that hard, that the cueball hops and you tighten your grip on your stroke you will enlarge the throw effect which means that you have to aim the objectball thinner to cut it in. Try to hold the cue very lightly even on hard shots to reduce the throw effect or compensate by aiming thinner or applying the right amount of english.

 

[mullyman]

Fantastic explanation. Rep to you.
MULLY
it should be equator though

 

[Ralph Kramden]

Hi
You can proove this when you put a dime on the table about 2 to 3 feet away from the cueball and then try to shoot the cueball hard in direction of the dime-you will see that the cueball will hop over the dime.

EKKES

Just make sure the windows are behind you!

 

[JE54]

Thanks for the explanation...........

 

[Falcon Eddie]

theUBC nailed it...hold the cue like your holding your grandma's hand..

 

[Gatz]

I don't think you're getting what i'm saying. I find with a hard hit on the cueball the object ball skids more it doesn't cut as good. I find myself adjusting for this anyways and making the ball. I just don't understand completely why this happens.

I wasn't talking about hitting it hard and over cutting the ball. This rarely happens for me. If I miss the a ball hit hard it's usually into the rail (undercutted). Shots where you kind of get straight in and you have to force it to get off the rail and into the centre of the table.

 

[12310bch]

when I quote you I get to see her again

Fantastic explanation. Rep to you.
MULLY
it should be equator though

I don't know Mullyman . Isn't the aquator where the most water or moisture accumulates on the cue ball in humid weather? :yeah:

 

[measureman]

Interesting . Never knew why but always knew that if i hit the cue ball high and feathered a thin cut shot it would have a better chance of going. I always thought it was friction, softer hit less friction. Just knew it worked.

 

[unknownpro]

I don't think you're getting what i'm saying. I find with a hard hit on the cueball the object ball skids more it doesn't cut as good. I find myself adjusting for this anyways and making the ball. I just don't understand completely why this happens.

I wasn't talking about hitting it hard and over cutting the ball. This rarely happens for me. If I miss the a ball hit hard it's usually into the rail (undercutted). Shots where you kind of get straight in and you have to force it to get off the rail and into the centre of the table.

If you are using outside english, the harder you hit the less curve you will get so you will hit the ball more full. The effect should be opposite with inside.

You may find that you are, as most people are, relying on cueball curve to pocket many shots and control your cueball. Most players start out looking at the cueball to object ball contact point and using mostly outside english. This requires either a crooked stroke or a healthy amount of curve to be successful, so it is a very natural player trap.

 

[Bob Jewett]

This seems like a weird question, but it seems like when I have to force a ball into a pocket I automatically over cut it a bit. I don't even understand why I do this, but I do.

Does the object ball skid/slide more when it is struck harder? Is this the reason why you would have to over cut it a bit more than usual?

I find this is even more obvious with just a below centre hit. With a top spin stroke, with the same speed, it seems that I don't have to over cut it as much. What would be the reasons for this, if any.

There is some throw on all shots. That is, the surface of the cue ball is somewhat sticky, and as it passes across the surface of the object ball, it will pull the object ball off the ideal path, which is the line through the centers of the two balls at the instant of contact.

If the cue ball is moving faster, there is not as much friction. This is contrary to the simple explanation of friction which says that the coefficient of friction does not change with the force of the contact. The reduction seems to be over a factor of two as you crank the speed up.

If you have stun on the cue ball (no follow or draw), the throw you see on a cut shot is maximized for that speed because all the rubbing is to the side. As you add draw or follow, the effective friction is reduced because part of the rubbing is up or down, and that doesn't contribute to the throw.

Most players have no idea that this stuff is going on, and to some extent it is better for them not to know. They learn subconsciously to make corrections for it, and if they start thinking about it during shots, their brain will get in the way of their arm.

There are fairly simple demonstrations for this. It is discussed on Dr. Dave's web site and in this article.

The cue ball also jumps on hard shots as mentioned above, but this causes thinner cuts mostly for short distances to the object ball or excess stick elevation.

Changing the grip has no direct effect on throw.

 

[instroke75]

There is some throw on all shots. That is, the surface of the cue ball is somewhat sticky, and as it passes across the surface of the object ball, it will pull the object ball off the ideal path, which is the line through the centers of the two balls at the instant of contact.

If the cue ball is moving faster, there is not as much friction. This is contrary to the simple explanation of friction which says that the coefficient of friction does not change with the force of the contact. The reduction seems to be over a factor of two as you crank the speed up.

If you have stun on the cue ball (no follow or draw), the throw you see on a cut shot is maximized for that speed because all the rubbing is to the side. As you add draw or follow, the effective friction is reduced because part of the rubbing is up or down, and that doesn't contribute to the throw.

Most players have no idea that this stuff is going on, and to some extent it is better for them not to know. They learn subconsciously to make corrections for it, and if they start thinking about it during shots, their brain will get in the way of their arm.

There are fairly simple demonstrations for this. It is discussed on Dr. Dave's web site and in this article.

The cue ball also jumps on hard shots as mentioned above, but this causes thinner cuts mostly for short distances to the object ball or excess stick elevation.

Changing the grip has no direct effect on throw.

You have entirely too much time on your hands! lol...no just kidding, that is a very good explaination.

Jeremy

 

[pt109]

wrong picture

I don't think you're getting what i'm saying. I find with a hard hit on the cueball the object ball skids more it doesn't cut as good. I find myself adjusting for this anyways and making the ball. I just don't understand completely why this happens.

I wasn't talking about hitting it hard and over cutting the ball. This rarely happens for me. If I miss the a ball hit hard it's usually into the rail (undercutted). Shots where you kind of get straight in and you have to force it to get off the rail and into the centre of the table.

I think you're cueing with a bit of outside english on these shots
resulting in a push effect.A sharply hit shot,especially with draw,
creates the contact closest to the ideal ghost ball angle.A softly hit
shot ,especially with top,creates a thick hit.
An airborn ball invaribly overcuts.
So if you're jacked up and speeding get used to missing on the thin
side or having your licence suspended.

..if i ever learn the table layout thing i have an excellent example
of how speed affects the cut....

 

[dr_dave]

Excellent post Bob ... certainly the most informative post I've read in a while.

If people want more info on all swerve and throw effects, I have a good summary (with lots of article links) here:

http://billiards.colostate.edu/threads/aiming.html#English_effects​

Regards,
Dave

There is some throw on all shots. That is, the surface of the cue ball is somewhat sticky, and as it passes across the surface of the object ball, it will pull the object ball off the ideal path, which is the line through the centers of the two balls at the instant of contact.

If the cue ball is moving faster, there is not as much friction. This is contrary to the simple explanation of friction which says that the coefficient of friction does not change with the force of the contact. The reduction seems to be over a factor of two as you crank the speed up.

If you have stun on the cue ball (no follow or draw), the throw you see on a cut shot is maximized for that speed because all the rubbing is to the side. As you add draw or follow, the effective friction is reduced because part of the rubbing is up or down, and that doesn't contribute to the throw.

Most players have no idea that this stuff is going on, and to some extent it is better for them not to know. They learn subconsciously to make corrections for it, and if they start thinking about it during shots, their brain will get in the way of their arm.

There are fairly simple demonstrations for this. It is discussed on Dr. Dave's web site and in this article.

The cue ball also jumps on hard shots as mentioned above, but this causes thinner cuts mostly for short distances to the object ball or excess stick elevation.

Changing the grip has no direct effect on throw.

 

[dr_dave]

An airborn ball invaribly overcuts.
So if you're jacked up and speeding get used to missing on the thin
side

Here's a good video demo of this effect:

HSV B.37 - jump shot over-cut effect and examples​

Regards,
Dave

 

[enzo]

This seems like a weird question, but it seems like when I have to force a ball into a pocket I automatically over cut it a bit. I don't even understand why I do this, but I do.

Does the object ball skid/slide more when it is struck harder? Is this the reason why you would have to over cut it a bit more than usual?

I find this is even more obvious with just a below centre hit. With a top spin stroke, with the same speed, it seems that I don't have to over cut it as much. What would be the reasons for this, if any.

oooh, good one! especially with center ball i have noticed you do need to overcut slightly more, probably because the point of compression between the 2 balls is much larger thus producing more friction and throw of the ball.

the top spin effect you speak of, i think you are right again. if you think about it, when the cueball is spinning, there will be less chance for friction to build up because the balls wont be sticking together as much. contrary to popular belief, ANY spin (inside, outside, top bottom) produces this effect, ie, the ob will really only be thrown WAY off course with a center ball type hit.

 

[pt109]

thanks Doc

Here's a good video demo of this effect:

HSV B.37 - jump shot over-cut effect and examples​

Regards,
Dave

That was great - just the way my mind saw it.
the last shot was illuminating,never thought of that application

 

[enzo]

Here's a good video demo of this effect:

HSV B.37 - jump shot over-cut effect and examples​

Regards,
Dave

so dave, for each unit of measurement the ob is off the slate, this will be counteracted exactly by the "recession" of the airborn cueball with that same (yet opposite) unit of measurement. in other words, the overcut effect we think exists upon impact by hitting the top of the ob will be counteracted by the curvature in the bottom of the cb. that is, i think a ball in the air obviously wont hit the same exact contact point, but it will hit on the same (toward the pocket) axis. yet the downward hitting nature of these shots could obviously throw the ob in a different way, but i don't think the cut axis (plane where the cb hits ob toward pocket) will change on many jumps shots-- read below for exceptions.

shots this will NOT be true for are say paper thin hits where if you are in the air you'd actually miss the ob, as that part of it wouldn't exist on that plane. also, this will not be true on shots where the cb jumps over the "incoming" contact point and comes down on the other side of the ob.

i dont think that last clip in the video proves anything because 1) you can see the ob go to the EXTREME undercut side of the pocket 2) in the slow motion version you can see a tad of outside on the cb, perhaps helping spin it on a tad 3) you said yourself it took an enormous number of tries to get it on video, perhaps because it actually isn't a feasible shot, only feasible due to the imperfections in the design (eg large pockets, spin on cb). I just think that shot MAY have been possible by spinning it in with a level stroke. now you could do an "impossible" cut if you "passed over" the ob as described in the paragraph above-- you could get some crazy cuts, even backwards, this way.

i really believe this is something pool players have long looked at incorrectly. as to why we think we overcut these shots?? i'll leave that up to others to decide-- perhaps the fact that many times, as pointed out above, you CAN "pass" (hop over and hit on the "other side") the "incoming" contact point, especially on thinner cuts.

kind regards, as i love all your stuff, but i think the results and design of this one are off base.

 

[dr_dave]

Here's a good video demo of this effect:

HSV B.37 - jump shot over-cut effect and examples

so dave, for each unit of measurement the ob is off the slate, this will be counteracted exactly by the "recession" of the airborn cueball with that same (yet opposite) unit of measurement. in other words, the overcut effect we think exists upon impact by hitting the top of the ob will be counteracted by the curvature in the bottom of the cb. that is, i think a ball in the air obviously wont hit the same exact contact point, but it will hit on the same (toward the pocket) axis. yet the downward hitting nature of these shots could obviously throw the ob in a different way, but i don't think the cut axis (plane where the cb hits ob toward pocket) will change on many jumps shots-- read below for exceptions.

shots this will NOT be true for are say paper thin hits where if you are in the air you'd actually miss the ob, as that part of it wouldn't exist on that plane. also, this will not be true on shots where the cb jumps over the "incoming" contact point and comes down on the other side of the ob.

i dont think that last clip in the video proves anything because 1) you can see the ob go to the EXTREME undercut side of the pocket 2) in the slow motion version you can see a tad of outside on the cb, perhaps helping spin it on a tad 3) you said yourself it took an enormous number of tries to get it on video, perhaps because it actually isn't a feasible shot, only feasible due to the imperfections in the design (eg large pockets, spin on cb). I just think that shot MAY have been possible by spinning it in with a level stroke. now you could do an "impossible" cut if you "passed over" the ob as described in the paragraph above-- you could get some crazy cuts, even backwards, this way.

i really believe this is something pool players have long looked at incorrectly. as to why we think we overcut these shots?? i'll leave that up to others to decide-- perhaps the fact that many times, as pointed out above, you CAN "pass" (hop over and hit on the "other side") the "incoming" contact point, especially on thinner cuts.

kind regards, as i love all your stuff, but i think the results and design of this one are off base.

I disagree. The best way to see the effect is to hold a CB up against an OB and visualize a 1/2-ball hit (center-to-edge). Now slide the CB up on the OB, keeping the CB center in the CTE plane. You will clearly see that different cut angles result, which you can verify by tapping the OB with the CB at different positions.

Try it out,
Dave

PS: Your statement about this effect not affecting many jump shots might be true; because on many jump shots, the CB might not be airborne when it hits the OB.