System to Compensate for Squirt and Throw

[Colin Colenso]

After experimenting with a method of dealing with squirt and throw, which I have discussed here a few times recently, I though a few here would like to see a reasonably simple graphic representation of the solution as it currently stands.

You use the graph below by firstly determining the length from Cue Ball to Object Ball, and the degree of Speed which you will play the shot at.

The graph is for my own cue. If you have a low deflection cue, you may need to add a couple of inches to every bridge length, but I think the graph will work quite well for most cues on most shots. If you're out by a few inches, it should only reduce the accuracy by about a degree or so, or 1/4 pocket over 3 feet to the pocket.

For the newbies, how it works is that you line determine the bridge length based on these two variables (which I found are the most critical). Line up the shot as if you're playing it center Cue Ball at medium speed.

Then simply pivot the backhand (backhand english) so that your tip is now aligned to whichever part of the Cue Ball you need to hit to get the english you want. Cue straight along this line.

The reason for all this is because simply BHE pivoting will not work for all speeds and distances. This chart makes an approximation of how to adjust for the variations.

Thanks to Drivermaker and Fred (Cornerman) for harrassing me enough to look more deeply into systems for aiming and compensating, rather than simply guessing or memorizing hundreds of effects.

An important point is the speed adjustment I noted in experiments. This is more than simple reduced throw or swerve effect. The CB definitely squirts more at higher speeds and it is a critical factor in using this type of alignment system for various speed shots.

 

[Colin Colenso]

bump...no more interest in throw / squirt compensation?

I thought the mere mention of DM might prompt a response

 

[Flex]

bump...no more interest in throw / squirt compensation?

I thought the mere mention of DM might prompt a response

Very interesting chart, Colin. Did you actually shoot shots at each of the distances to come up with those curves, or are there some extrapolations employed? Also, while the chart is definitely useful and hopefully will give the naysayers something to think about, it's just the beginning, of course. For when table conditions are not normal, realtime adaptation is called for.

For instance, if the humidity in the room were to go up very rapidly, and get really wet and sticky, do you have any idea how one should compensate in that circumstance?

Flex

 

[PoolSleuth]

After experimenting with a method of dealing with squirt and throw, which I have discussed here a few times recently, I though a few here would like to see a reasonably simple graphic representation of the solution as it currently stands.

You use the graph below by firstly determining the length from Cue Ball to Object Ball, and the degree of Speed which you will play the shot at.

The graph is for my own cue. If you have a low deflection cue, you may need to add a couple of inches to every bridge length, but I think the graph will work quite well for most cues on most shots. If you're out by a few inches, it should only reduce the accuracy by about a degree or so, or 1/4 pocket over 3 feet to the pocket.

For the newbies, how it works is that you line determine the bridge length based on these two variables (which I found are the most critical). Line up the shot as if you're playing it center Cue Ball at medium speed.

Then simply pivot the backhand (backhand english) so that your tip is now aligned to whichever part of the Cue Ball you need to hit to get the english you want. Cue straight along this line.

The reason for all this is because simply BHE pivoting will not work for all speeds and distances. This chart makes an approximation of how to adjust for the variations.

Thanks to Drivermaker and Fred (Cornerman) for harrassing me enough to look more deeply into systems for aiming and compensating, rather than simply guessing or memorizing hundreds of effects.

An important point is the speed adjustment I noted in experiments. This is more than simple reduced throw or swerve effect. The CB definitely squirts more at higher speeds and it is a critical factor in using this type of alignment system for various speed shots.

DAAAAH I do not see where you have factored in anything but a True Center Ball Hit....

 

[Colin Colenso]

Very interesting chart, Colin. Did you actually shoot shots at each of the distances to come up with those curves, or are there some extrapolations employed? Also, while the chart is definitely useful and hopefully will give the naysayers something to think about, it's just the beginning, of course. For when table conditions are not normal, realtime adaptation is called for.

For instance, if the humidity in the room were to go up very rapidly, and get really wet and sticky, do you have any idea how one should compensate in that circumstance?

Flex

This chart is based on my own testing of a range of distances with different speeds and by noticing the trends, the curves were extrapolated. I think it will change with more work, but not by much. It should be a very useful guide for anyone to use as it is.

It's certainly much better than simply doing BHE with the same bridge length for all the shots, and it will show people why close to OB BHE doesn't work so well, or requires a very long bridge length.

I don't think humidity will matter much, though it might require lengthening the bridge a couple of inches as the SIT will be a bit larger. But swerve may increase also and cancel this out. I'd need to play in humid conditions to check it out.

The biggest factor will be the player's particular cue, but I suspect the variation won't be as much as many think. Hopefully some can try it out with different cues and see what variation they find.

Note: I have not included any adjustments for top or bottom spin. I need to do more testing on this. I don't think it will be large adjustments though, as the shots seem to be working well with for top and bottom already.

 

[Colin Colenso]

DAAAAH I do not see where you have factored in anything but a True Center Ball Hit....

This system is supposed to work for all angles of shots with all amounts of english.

The initial aim is taken by aligning to the pot as if no english was being played.

Now how to do that is another question that people use various systems to achieve. My prefered system at this stage is to just visualize the OB to pocket looking through the center of the CB until the line of the cue feels right. Someone could alternatively use Joe Tucker's or Hal Houle's or Ghost Ball whatever other systems to achieve this.

 

[2wld4u]

on sharper cut's I use say low right or outside english to the shot and shoot the actual aim point, Red is the target path, the yellow is the actual cue ball path.



START(
%AN7O5%BL7P8%CJ5O4%DL7N1%EM7P1%FK6P1%GK6N8%Hq1L0%IL7O4%JK6M5
%KJ5P7%LJ5N2%MK6Q4%NJ5R0%OJ5M0%PX0P2%Wo9M2%XX0P2%]s3C8%^q0L2
%eC8b1%bp0M2%cc4N0%dX6P2
)END

 

[Colin Colenso]

on sharper cut's I use say low right or outside english to the shot and shoot the actual aim point, Red is the target path, the yellow is the actual cue ball path.



START(
%AN7O5%BL7P8%CJ5O4%DL7N1%EM7P1%FK6P1%GK6N8%Hq1L0%IL7O4%JK6M5
%KJ5P7%LJ5N2%MK6Q4%NJ5R0%OJ5M0%PX0P2%Wo9M2%XX0P2%]s3C8%^q0L2
%eC8b1%bp0M2%cc4N0%dX6P2
)END

This shot can work fine so long as you shoot it from the same distance and with the same bridge length.

However, align the same from closer or further away and the shot will miss.

 

[PoolSleuth]

Colin you put a lot of work in your system I do not totally understand it, but I think i will study it, and I will give it a try.

 

[jsp]

Hi Colin. I'm still not understanding the main purpose of the chart. Why exactly are you charting the distance between CB and OB? If you're compensating for squirt, then that shouldn't matter at all, unless you're taking into account swerve (are you?). I would think what matters more is the distance between OB and the pocket, since throw would be magnified the further the OB is away from the pocket. I'm still just trying to understand the chart. Thanks.

 

[DaveK]

Colin,

Do I understand correctly that the curves suggest that you use a bridge length of 20" for some shots (close shots it looks like) ? Just off the top of my head I cannot see myself shooting accurately with anywhere near that long a bridge.

Also, just out of curiosity, how many data points were collected to plot this solution ? Did you use any instrumentation to ensure accurate measurements of speed and distance ?

Dave

 

[Cornerman]

Colin,

Do I understand correctly that the curves suggest that you use a bridge length of 20" for some shots (close shots it looks like) ? Just off the top of my head I cannot see myself shooting accurately with anywhere near that long a bridge.

It would be "pivot length" for standard BHE.

Fred

 

[pete lafond]

Colin,

Do I understand correctly that the curves suggest that you use a bridge length of 20" for some shots (close shots it looks like) ? Just off the top of my head I cannot see myself shooting accurately with anywhere near that long a bridge.

Also, just out of curiosity, how many data points were collected to plot this solution ? Did you use any instrumentation to ensure accurate measurements of speed and distance ?

Dave

Over the years most adjustments were made by how we bridged which effects the outcome. Some shots require a tighter bridge while others an extremely loose one. Tighter the bridge, the firmer the shaft becomes and that changes things like deflection. (I am not talking about length of bridge rather the firmness)

This is why ALL bridges are required to play this game because if you don't you will never experience the differences. It is these experiences that become intuitive and you never give it a second thought. This belongs in the feel category which is developed over time.

I can think of instances were I want to keep the shaft perfectly firm allowing no flex at all, to do this requires a very firm bridge and an extremely loose grip. Other cases were a very loose bridge and a little more firm grip when I want to whip the CB with more excessive English.

I would have never thought of this if posts like this did not come up because just like the many aiming systems we use, it is so engrained in our game that we do not consciously notice it.

Keep in mind that most shots taken are simply shot without consideration to these effects because most shots are not affected. It is only those few shots.

 

[Colin Colenso]

Hi Colin. I'm still not understanding the main purpose of the chart. Why exactly are you charting the distance between CB and OB? If you're compensating for squirt, then that shouldn't matter at all, unless you're taking into account swerve (are you?). I would think what matters more is the distance between OB and the pocket, since throw would be magnified the further the OB is away from the pocket. I'm still just trying to understand the chart. Thanks.

Hi jsp,
It turns out that the distance between CB and OB is the critical factor. The distance of the OB to pocket doesn't matter, as the whole point is to contact the OB and send it along a line to the pocket, regardless whether it is 2" or 80" away.

The reason the distance from CB to OB is so important is that the CB should not contact at the OB at the point we are aligning to. It hits thicker with OE and thinner with IE. We actually align to where we would hit the OB with a center cuing medium speed stroke, just as if we were rolling the balls in.

At close distances, the spin on the CB turns the OB more than the squirt moves the CB away to compensate, so we need a bridge length longer than the pivot point.

For short shots under 1 foot, it is hard to get enough squirt to overcome the Spin Induced Throw (SIT), unless you hit very hard which both increases squirt and decreases SIT. For these shorter shots there are options such as:
1. Parallel English
2. Reverse Swiping to increase the effective amount of squirt.
3. Line the shot up to slightly undercut with OE or to overcut with IE.
4. Just play by feel as these close shots are usually pretty easy anyway.

The further the CB is from the OB, the less squirt is required over distance to strike the OB just those couple of mm off aim to compensate for the SIT. So the bridge length drifts toward the natural pivot point which send the CB on the same line regardless of english.

I have found that the cue's natural pivot point varies with speed. Harder hit = shorter pivot point. Though with further testing today I need to revise my graph to make these lines closer and bridge lengths slightly longer for the long shots.

The reason I made this error was because I was unconsciously swiping the CB a little during testing. Today I ran the cue along my chin to make sure I moved the cue in a straight line. This made a significant difference in reducing the amount of squirt deflection.

It appears straigh cuing is absolutely paramount for making this sytem consistant on longer shots.

It is a great feeling to pump in balls consistantly with a 48" gap loading up with english. But if you can't line up a shot with a 48" gap accurately anyway, it won't help much unless the OB is close to the pocket.

As for swerve, the system may be taking account of this automatically, though most shots where you'll use this system are quite firm so swerve is minimal. I haven't noticed any appreciable difference between follow and draw using the system, but more testing is required on that.

One thing is for sure. Already the bridge length adjustments, though still a work in progress, are a much better starting point for BHE, which until now, did not take into account speed, CB-OB distance and did not use bridge length adjustments. Hence, the scope of use of the system can be increased accurately to a wide range of shots where english could be utilized.

 

[Colin Colenso]

Colin,

Do I understand correctly that the curves suggest that you use a bridge length of 20" for some shots (close shots it looks like) ? Just off the top of my head I cannot see myself shooting accurately with anywhere near that long a bridge.

Also, just out of curiosity, how many data points were collected to plot this solution ? Did you use any instrumentation to ensure accurate measurements of speed and distance ?

Dave

Yes Dave,
Some shots that are close at medium speed require a bridge length of 20" or over, though it is not a lot. My standar open bridge length is about 14", open bridge from thumb V to CB. I had assumed it was 10" until I measured it as my fingertips look quite close. 20" is about my comfort limit but even on most of the shorter shots that require a 20" plus bridge length, I simple bridge at my standard bride length and aim 1/2 pocket thicker with OE and 1/2 pocket thinner with IE. These shots are pretty easy anyway so you'll quickly adapt if you understand how everything relates.

For the data points I played half a dozen shots or so at slow, medium and hard shots at distance intervals of 12", 15", 18", 24", 30", 36", 48" and 60".

This combined with a lot of random shots using some of these results as guidelines.

The accuracy relies on my initial ability to align correctly (I do it with straight in shots as these are the most reliable for alignment), and my accuracy in cuing straight through the line of bridge point to CB contact point (no swiping). In my initial tests it seemed I was a bit careless and tended to swipe, as more rigorous testing today indicated lower squirt with straight cuing, hence longer bridge lengths for the larger distances b/w CB and OB.

This finding was actually quite pleasing, as I've found many shots which have CB-OB separation of 3 to 4 feet, playing firm, now fall into the range of my natural bridge length. These are the kind of shots that can come in very handy in a game for moving the CB around the table, but usually present too dangerous a challenge for most players to attempt.

Colin

 

[Colin Colenso]

Over the years most adjustments were made by how we bridged which effects the outcome. Some shots require a tighter bridge while others an extremely loose one. Tighter the bridge, the firmer the shaft becomes and that changes things like deflection. (I am not talking about length of bridge rather the firmness)

This is why ALL bridges are required to play this game because if you don't you will never experience the differences. It is these experiences that become intuitive and you never give it a second thought. This belongs in the feel category which is developed over time.

I can think of instances were I want to keep the shaft perfectly firm allowing no flex at all, to do this requires a very firm bridge and an extremely loose grip. Other cases were a very loose bridge and a little more firm grip when I want to whip the CB with more excessive English.

I would have never thought of this if posts like this did not come up because just like the many aiming systems we use, it is so engrained in our game that we do not consciously notice it.

Keep in mind that most shots taken are simply shot without consideration to these effects because most shots are not affected. It is only those few shots.

Hi Pete,
You may be right about the firm bridge and loose grip having an effect. Though I have read some of the knowledgeable physics guys say it is unlikely to have an effect, as they say the flesh moves to easily over the 1-2,000ths of a second of tip-CB contact. Still, I don't find this argument entirely convincing.

They also claim that speed does not affect squirt, but as I test more and more, I believe it is significant, and it is not simply an illusion that is created by speed reducing SIT. Though this effect certainly exagerates the appearance.

Your own method could also be systemized if it works. It should at least make us take into account grip and bridge tightness as a variable in the system I am proposing to be either utilized or kept constant for particular shots.

At the moment though, I think I have all the variables I can handle Though I'll try some tight v loose grips for squirt pivot point determination to satisfy my curiosity.

Colin

 

[Andrew Manning]

Do you use it?

Colin, I'm impressed by your ability to consider all these variables in combination and come up with a seemingly inclusive system to relate them all. What do you do for a living? I'll be surprised of you don't say you're an engineer of some sort.

However, I myself am an engineer, and I can't even imagine thinking about this stuff while shooting a shot. My question is, although you've come up with a great system to explain how squirt and throw can be controlled and used by varying bridge length and using BHE, do you actually use this system, as written, while playing? I mean really playing, and not just shooting shots to test your theories.

I personally believe that only my subconscious can be relied on to accurately measure and compute the variables in a system like this, and if I try to do it with conscious calculation, I'll inevitably screw it up. I try to understand factors like squirt, throw, and their interplay intellectually, but when it comes to shooting, I rely on my intuition to actually make them happen. I'm curious to hear whether you think systems as complicated as this are really practical in match play.

-Andrew

 

[jsp]

Hi jsp,
It turns out that the distance between CB and OB is the critical factor. The distance of the OB to pocket doesn't matter, as the whole point is to contact the OB and send it along a line to the pocket, regardless whether it is 2" or 80" away.

The reason the distance from CB to OB is so important is that the CB should not contact at the OB at the point we are aligning to. It hits thicker with OE and thinner with IE. We actually align to where we would hit the OB with a center cuing medium speed stroke, just as if we were rolling the balls in.

At close distances, the spin on the CB turns the OB more than the squirt moves the CB away to compensate, so we need a bridge length longer than the pivot point...

Thanks for the detailed reply Colin. I better understand now. So SIT is already compensated for in this system.

However, the graph seems to only apply for a certain tip offset? What if you impart more spin on the CB (greater tip offset)? The greater spin would throw the OB further.

We must also keep in mind that the pivot point of a cue depends on the tip offset. According to Ron Shepard's paper, a different tip offset would result in different pivot point.

 

[pete lafond]

Hi Pete,
You may be right about the firm bridge and loose grip having an effect. Though I have read some of the knowledgeable physics guys say it is unlikely to have an effect, as they say the flesh moves to easily over the 1-2,000ths of a second of tip-CB contact. Still, I don't find this argument entirely convincing.

They also claim that speed does not affect squirt, but as I test more and more, I believe it is significant, and it is not simply an illusion that is created by speed reducing SIT. Though this effect certainly exagerates the appearance.

Your own method could also be systemized if it works. It should at least make us take into account grip and bridge tightness as a variable in the system I am proposing to be either utilized or kept constant for particular shots.

At the moment though, I think I have all the variables I can handle Though I'll try some tight v loose grips for squirt pivot point determination to satisfy my curiosity.

Colin

Just like I explained that feel controls a pitchers curve in baseball the cue stick controls the CB. The stick is an extension to our bodies (as if it were part of us) and we feel the CB through our stick, we do not feel the stick unless we have become too self conscious.

I grew up playing hockey and used to practice with some of the pros in my earlier years. One of the reasons is that I had an inside shot that goalies had difficulty with. The only reason I bring this up is that I always felt the puck through my hockey stick. Deflection, flex and the same things we talk about here apply there as well. I controlled the things I wanted to do with the puck through my grip to ultimately control the stick. Likewise, I handle the CB with feel also and the things that I make happen, happens through my hands and cue stick.

We control and handle all of our pool shots through our hands and the stick. Just as we might tense up our muscles to achieve an effect in one sport, we change the grip and bridge to change an effect in a pool shot in pool. Every shot including a hop shot (using high English to hop over the edge of a ball in the path of the OB), draw, follow. side English, ... are all feel shots. Again, just like the pitcher in baseball, the hockey player, the tennis player, .. our sense of feel becomes the conditioning factor for us. This is achieved over time. Those that learn how to control through feel better than others are often the better players.

I believe that knowing squirt, throw, bounce, humidity,.. and all that affects our shot are important to know. But the real system to dealing with these things are just like in other sports, the player develops feel and adapts. Some play more often than others and some develop the feel better than others.

 

[Colin Colenso]

Thanks for the detailed reply Colin. I better understand now. So SIT is already compensated for in this system.

However, the graph seems to only apply for a certain tip offset? What if you impart more spin on the CB (greater tip offset)? The greater spin would throw the OB further.

We must also keep in mind that the pivot point of a cue depends on the tip offset. According to Ron Shepard's paper, a different tip offset would result in different pivot point.

jsp,
Very good question re the tip offset. To give a brief answer, it works for all tip offsets. At least, I have not found any differences yet worth noting.

In more detail now: Why the tip offset makes little difference with (BHE) but not for parallel aiming english is that the further you pivot the cue, hence the direction of hit, this compensates for the increase squirt. So it basically cancels out within the acceptable margin for error. We also have the effect of increased english from higher offsets throwing the OB a little further, but again, the combination of these opposing factors seems to cancel out.

I wouldn't be surprised if with testing I find it useful to reduce or add a couple of inches to my bridge length for shots using extreme english versus medium or a touch of english.

Fact is, most the time when you're playing (let's say a top right) english shot, to get the required result, just one tip of english is enough to get the run needed. More often that not the degree of follow or depth of bottom is more critical than the degree of side english in developing positional angles.

Colin