One-rail kick power/spin choices for smallest margin of error

[Oikawa]

First of all, to ensure clarity in what I will be talking about, here's an image of one-rail mirror lines; the paths that the cue ball would travel, if the cushions behaved in the mathematically simplest possible way. Checking where you'd need to aim for a mirror kick (using, for example, one of many variations of the basic "mirror system"), works as a great baseline that you then make adjustments to, depending on the table, power, spin, elevation, etc.

(Mirror line examples)

To avoid misunderstandings, and to avoid answers derailing into "every shot is different, there's no gain in generalizing that" or "that's a wrong shot choice", let's assume that you want to, for whatever reason, perform an one-rail kick shot, such that your only goal is to pot the object ball with the biggest percentages of doing so. Example situation from 8-ball (you are stripes):

Given the mirror kick line, it would look like this:

Now, you can't simply blindly aim for this spot, and expect the 8 to go in. You need to consider what factors can affect the rebound angle or curving of the cue ball.

What I'd like to discuss in this topic is a generalization of that situation: Which combination of the factors that you can control (spin, power, elevation) gives the smallest margin for one-rail kicks? Should you prefer to alter your spin, power or shot angle for the adjustment? How to make the shot least sensitive to shot power in various types of one-railers?

First of all, it can be easily ruled out that using sidespin or sidespin + elevation (swerve), are generally bad ways of achieving a consistent adjustment method for kicks, due to their sensitivity in the speed of the shot. That leaves us with power and spin along the top/down axis.

Secondly, you also need to consider the variables of the table layout itself for every shot; the rebound angle, and distance of CB and OB from the rebound point.

You will also need to consider other uncontrollable non-layout related factors such as the table/rail conditions, humidity etc.

So, with those in mind, going back to the 8-ball example above, once you decided you want to kick the ball in, your process could be the following:
1. Check the mirror line contact point.
2. Choose a certain speed/spin to shoot with, and/or make the required angle adjustment from that original contact point.
3. Adjust from there based on the table conditions, humidity etc.

Let's focus on step 2 = How should you determine which speed/spin to use for certain types of one-rail kicks, to minimize your margin of error?

A basic insight I have is that is it generally worse to require speed adjustments, over tip position or angle adjustments, due to the latter two being much easier to execute reliably.

One approach could be to just pick one speed/spin (such as center high cueball with firm pace, or center high cueball with soft pace), and adjust your shooting angle based on the layout variables (the angle of the rebound and distance of OB/CB from the rebound point), either by feel or by some mathemathical methods. With this approach, I'd be curious to hear peoples opinions on what you find to be the most consistent spin/speed combination for various angles or various table conditions?

I have been experimenting with this method using center high cueball with firm pace, and it works very well across different powers for some tables, such that if you adjust for the angle of the shot, you can shoot it soft, medium or hard and the output will be almost the same. On other tables, this isn't true, and you need to be much more aware of the pace. Perhaps someone has some data on this; which Y-axis tip position gives the smallest difference in outcomes for different shot angles in one-rail kicks, when varying shot speed only? It seems obvious that bottom spin is very sensitive to power, but it can't be so easily deducted whether center, top, or something inbetween those two is the least sensitive.

Another approach could be to not adjust the shooting angle from the original mirror point, but rather pick your power/spin such that the shot will go in. As mentioned before, I find this approach worse than the previous one, due to cueball speed being so difficult to control precisely, compared to adjusting the shooting angle.

Do you have any thought about this? I'm not looking for specific kicking systems e.g. diamond systems, but rather general insights about how you handle adjustments in your one-rail kicks, no matter the original method of figuring out the baseline. Maybe some self-correcting shots, where two variables cancel eachother out nicely? Or common misconceptions? Any insights are appreciated.

 

[Patrick Johnson]

First of all, to ensure clarity in what I will be talking about, here's an image of one-rail mirror lines; the paths that the cue ball would travel, if the cushions behaved in the mathematically simplest possible way. Checking where you'd need to aim for a mirror kick (using, for example, one of many variations of the basic "mirror system"), works as a great baseline that you then make adjustments to, depending on the table, power, spin, elevation, etc.

View attachment 728403
(Mirror line examples)

To avoid misunderstandings, and to avoid answers derailing into "every shot is different, there's no gain in generalizing that" or "that's a wrong shot choice", let's assume that you want to, for whatever reason, perform an one-rail kick shot, such that your only goal is to pot the object ball with the biggest percentages of doing so. Example situation from 8-ball (you are stripes):

View attachment 728417

Given the mirror kick line, it would look like this:

View attachment 728418

Now, you can't simply blindly aim for this spot, and expect the 8 to go in. You need to consider what factors can affect the rebound angle or curving of the cue ball.

What I'd like to discuss in this topic is a generalization of that situation: Which combination of the factors that you can control (spin, power, elevation) gives the smallest margin for one-rail kicks? Should you prefer to alter your spin, power or shot angle for the adjustment? How to make the shot least sensitive to shot power in various types of one-railers?

First of all, it can be easily ruled out that using sidespin or sidespin + elevation (swerve), are generally bad ways of achieving a consistent adjustment method for kicks, due to their sensitivity in the speed of the shot. That leaves us with power and spin along the top/down axis.

Secondly, you also need to consider the variables of the table layout itself for every shot; the rebound angle, and distance of CB and OB from the rebound point.

You will also need to consider other uncontrollable non-layout related factors such as the table/rail conditions, humidity etc.

So, with those in mind, going back to the 8-ball example above, once you decided you want to kick the ball in, your process could be the following:
1. Check the mirror line contact point.
2. Choose a certain speed/spin to shoot with, and/or make the required angle adjustment from that original contact point.
3. Adjust from there based on the table conditions.

Let's focus on step 2 = How should you determine which speed/spin to use for certain types of one-rail kicks, to minimize your margin of error?

A basic insight I have is that is it generally worse to require speed adjustments, over tip position or angle adjustments, due to the latter two being much easier to execute reliably.

One approach could be to just pick one speed/spin (such as center high cueball with firm pace, or center high cueball with soft pace), and adjust your shooting angle based on the layout variables (the angle of the rebound and distance of OB/CB from the rebound point), either by feel or by some mathemathical methods. With this approach, I'd be curious to hear peoples opinions on what you find to be the most consistent spin/speed combination for various angles or various table conditions?

I have been experimenting with this method using center high cueball with firm pace, and it works very well across different powers for some tables, such that if you adjust for the angle of the shot, you can shoot it soft, medium or hard and the output will be almost the same. On other tables, this isn't true, and you need to be much more aware of the pace. Perhaps someone has some data on this; which Y-axis tip position gives the smallest difference in outcomes for different shot angles in one-rail kicks, when varying shot speed only? It seems obvious that bottom spin is very sensitive to power, but it can't be so easily deducted whether center, top, or something inbetween those two is the least sensitive.

Another approach could be to not adjust the shooting angle from the original mirror point, but rather pick your power/spin such that the shot will go in. As mentioned before, I find this approach worse than the previous one, due to cueball speed being so difficult to control precisely, compared to adjusting the shooting angle.

Do you have any thought about this? I'm not looking for specific kicking systems e.g. diamond systems, but rather general insights about how you handle adjustments in your one-rail kicks, no matter the original method of figuring out the baseline.

One answer is sliding the cue ball with gearing running side spin - to neutralize table condition variances.

Another is rolling the cue ball aimed at a point on the rail a certain distance behind the cushion nose target (such as even with the diamonds) to compensate for the rolling follow widening the rebound angle.

pj
chgo

 

[Oikawa]

One answer is sliding the cue ball with gearing running side spin - to neutralize table condition variances.

Another is rolling the cue ball aimed at a point on the rail a certain distance behind the cushion nose target (such as even with the diamonds) to compensate for the rolling follow widening the rebound angle.

pj
chgo

For answer 1:

Interesting, never heard of this. Why does that neutralize table condition variances, can you clarify more on the reasoning?

For answer 2:

This seems like a nice starting point for a method, especially when the shot at hand requires soft speed. The question then becomes how would you most effectively decide on how much to adjust the angle given the variables of the shot at hand? Shallower angle = more compensation (although the method you said of adjusting by aiming behind the cushion nose target by some amount already accounts for this in a self-correcting fashion by having the aim offset be larger for shallower angles, but it must have some degree of error still, so some sort of extra-adjustment based on the shot angle will make it more precise), and have to consider the CB-to-rail and rail-to-OB distances too (for example, if the shot path before collision with OB is 90% before cushion and 10% after, the necessary compensation clearly won't be the same as if the shot path was 10% before cushion and 90% after), so perhaps there is some clever math to make this more precise than having a certain baseline and either not adjusting for angle, or adjusting purely by feel.

Of course you can never derive a perfect formula that accounts for all possible variables, but all tiny steps of extra consistency add up in the long run.

 

[bbb]

i am not an instructor
but for one rail kicks if the in /out line is there i use medium spieed and a rolling cue ball
(1 tip above horizontal)
and adjustment would be how the table plays
would only use spin if the in/ out angle were blocked and i had to manufacture the angle
one rail kicks are discussed very thoroughly if you do a search
no need to reinvent the wheel
jmho

 

[FranCrimi]

In playing an actual game where a kick shot is necessary, the player utilizes speed and spin for different reasons than you are suggesting. One use is to adjust the angle due to an object ball blocking the path of the optimal angle --- which is often the case. If you need to widen or shorten the angle due to a blocking ball, you need to do it with spin and speed.

But even when the player does have an optimal situation where he can shoot the kick unobstructed --- his priority for spin and speed is to control the outcome of the kick to whatever extent that he can.

 

[Oikawa]

In playing an actual game where a kick shot is necessary, the player utilizes speed and spin for different reasons than you are suggesting. One use is to adjust the angle due to an object ball blocking the path of the optimal angle --- which is often the case. If you need to widen or shorten the angle due to a blocking ball, you need to do it with spin and speed.

But even when the player does have an optimal situation where he can shoot the kick unobstructed --- his priority for spin and speed is to control the outcome of the kick to whatever extent that he can.

I wasn't suggesting a naive all-working method for all shots existing, obviously spin and speed, what happens if you miss, maximizing probability of winning the frame taking everything into consideration, needs to be considered in all sorts of ways in individual shots just as you say. Which is exactly why I mentioned that I'm focusing on cases where we ignore all that, and think about insights for when there are no blockers in the way, and the only focus is to hit the desired point with the smallest margin of error.

Talking on that level is not meant to represent the full decision process when faced with a shot in a real game (which would indeed be very naive), but rather to find insights in isolation for one element of the shot (in this case, minimizing one-rail kick margin of error for cueball angle deviation from target) which can then be used in a real game to make a more nuanced decision, aiding the shot selection. In other words, isolating variables or looking at simplified examples like this to form generalizable "rules of thumb" can act as small parts of wisdom in the whole decision process.

 

[Oikawa]

i am not an instructor
but for one rail kicks if the in /out line is there i use medium spieed and a rolling cue ball
(1 tip above horizontal)
and adjustment would be how the table plays
would only use spin if the in/ out angle were blocked and i had to manufacture the angle
one rail kicks are discussed very thoroughly if you do a search
no need to reinvent the wheel
jmho

I've found some general discussion about them (both from this forum and elsewhere), but not much to do with the intricacies of adjusting with minimizing error margins for various angles in consideration. Made this thread to hear some less known, or more nuanced perspectives on one-railers, that perhaps aren't discussed as much as the basic principles that indeed have been repeated multiple times on here and many other forums and resources.

 

[FranCrimi]

I wasn't suggesting a naive all-working method for all shots existing, obviously spin and speed, what happens if you miss, maximizing probability of winning the frame taking everything into consideration, needs to be considered in all sorts of ways in individual shots just as you say. Which is exactly why I mentioned that I'm focusing on cases where we ignore all that, and think about insights for when there are no blockers in the way, and the only focus is to hit the desired point with the smallest margin of error.

Talking on that level is not meant to represent the full decision process when faced with a shot in a real game (which would indeed be very naive), but rather to find insights in isolation for one element of the shot (in this case, minimizing one-rail kick margin of error for cueball angle deviation from target) which can then be used in a real game to make a more nuanced decision, aiding the shot selection. In other words, isolating variables or looking at simplified examples like this to form generalizable "rules of thumb" can act as small parts of wisdom in the whole decision process.

I know what you're saying, and I'm saying that these nuances that you're seeking out won't come into play in an actual match because there are too many other variables that take precedence. Do you test all the rails before you play a match so see how they are reacting to banks and kicks? You should. That should be your starting point.

 

[bbb]

i am not an instructor
the way to minimize errors is have the ability to impart NO SIDESPIN when trying to hit the cue ball with no spin
pure speculation on my part but i think many errors are caused by unintended tip placement

 

[Bob Jewett]

For the particular shot shown above from a game of eight ball, I think the kick should be played at a speed that does not scratch in case the cue ball comes in a little short.

For that particular shot, a good choice is to use the 2-to-1 ratio diamond system and a rolling cue ball. The system is known to work well for kicks at this angle into the cushion. The placement of the diamonds usually gives the required compensation (relative to the perfect mirror) for the slide/curve off the cushion due to the rolling ball. Also the speed required to avoid the scratch is within the good range of the system.

 

[23DenaliBDE]

i am not an instructor
but for one rail kicks if the in /out line is there i use medium spieed and a rolling cue ball
(1 tip above horizontal)
and adjustment would be how the table plays
would only use spin if the in/ out angle were blocked and i had to manufacture the angle
one rail kicks are discussed very thoroughly if you do a search
no need to reinvent the wheel
jmho

I would only add that if OP is looking for the most repeatability by minimizing variables, OP simply has to pick their most repeatable shot. You are correct, as is Bob and Fran in the replies. The reason everyone does things just a little differently within the same system is personal repeatability. If i attempt to impart 0 English, I miss often. For some reason I can be extremely consistent using a small amount of running English at medium to medium slow speed. I attempt to make my only change be amount and direction of English when I'm forced to miss blockers. If OP wants consistency OP just needs to hit enough balls to find out what is the most repeatable for them. Disclaimer- I know 0 except my own experience and everything I try and copy from Dr Dave vids

 

[Oikawa]

I know what you're saying, and I'm saying that these nuances that you're seeking out won't come into play in an actual match because there are too many other variables that take precedence. Do you test all the rails before you play a match so see how they are reacting to banks and kicks? You should. That should be your starting point.

Interesting take, although I'm still not sure if I see it that way. Definitely gives me something to think about and reflect on. Are you suggesting that the sort of nuances that are there to be found are too table specific to be generalizable past that, even on a weaker level?

And yes, I do a few baseline tests on new tables on a simple level to see if they e.g. kick long or short at soft, medium and hard speeds relative to what I am used to on my practice table. But this doesn't really give me any analytical insights, it just gives me a feel for the sort of adjustment I need to cancel that difference out. If I understood the physics and variables better, perhaps I could gain some more nuanced insights from this testing, instead of just a feel for baseline offset amounts for various speeds.

 

[Oikawa]

i am not an instructor
the way to minimize errors is have the ability to impart NO SIDESPIN when trying to hit the cue ball with no spin
pure speculation on my part but i think many errors are caused by unintended tip placement

I agree with this. Especially when forced to shoot jacked up next to a ball in a very awkward position, I try to be aware of this fact, that a seemingly much simpler route can have lower % of success than some other non-jacked up route, even if it was harder in theory if you always shot perfectly straight.

 

[Oikawa]

For the particular shot shown above from a game of eight ball, I think the kick should be played at a speed that does not scratch in case the cue ball comes in a little short.

For that particular shot, a good choice is to use the 2-to-1 ratio diamond system and a rolling cue ball. The system is known to work well for kicks at this angle into the cushion. The placement of the diamonds usually gives the required compensation (relative to the perfect mirror) for the slide/curve off the cushion due to the rolling ball. Also the speed required to avoid the scratch is within the good range of the system.

Is there mathemathical resources/information somewhere about the compensation effect of that system to minimize errors? The range of speeds it works well at, how well it works across different rebound angles, what type of benchmarking should be done when playing on a new table, etc.

I've heard about it, but always preferred to just use the mirror system with no rebound compensation (e.g. as I drew in my original post), and then adjust from there. With replies in this thread in mind, I now wonder if I should research this method more, I guess it mainly depends on just how well the compensation effect works across different angles, gotta do some testing when I get practicing next time.

 

[Oikawa]

I would only add that if OP is looking for the most repeatability by minimizing variables, OP simply has to pick their most repeatable shot. You are correct, as is Bob and Fran in the replies. The reason everyone does things just a little differently within the same system is personal repeatability. If i attempt to impart 0 English, I miss often. For some reason I can be extremely consistent using a small amount of running English at medium to medium slow speed. I attempt to make my only change be amount and direction of English when I'm forced to miss blockers. If OP wants consistency OP just needs to hit enough balls to find out what is the most repeatable for them. Disclaimer- I know 0 except my own experience and everything I try and copy from Dr Dave vids

While I agree with you mostly, for finding consistency from a practical standpoint, I don't think that those points take anything away from trying to find more nuanced understanding in minimizing errors by technical understanding vs. just relying on HAMB and experience. Both are valuable and work best hand in hand.

 

[bbb]

Is there mathemathical resources/information somewhere about the compensation effect of that system to minimize errors? The range of speeds it works well at, how well it works across different rebound angles, what type of benchmarking should be done when playing on a new table, etc.

I've heard about it, but always preferred to just use the mirror system with no rebound compensation (e.g. as I drew in my original post), and then adjust from there. With replies in this thread in mind, I now wonder if I should research this method more, I guess it mainly depends on just how well the compensation effect works across different angles, gotta do some testing when I get practicing next time.

Dr dave has alot of what you are looking for on his website

 

[23DenaliBDE]

While I agree with you mostly, for finding consistency from a practical standpoint, I don't think that those points take anything away from trying to find more nuanced understanding in minimizing errors by technical understanding vs. just relying on HAMB and experience. Both are valuable and work best hand in hand.

Agreed. Execution will always be the absolute most important factor, though

 

[Patrick Johnson]

One answer is sliding the cue ball with gearing running side spin - to neutralize table condition variances.

Interesting, never heard of this. Why does that neutralize table condition variances, can you clarify more on the reasoning?

A sliding CB with gearing running english avoids rubbing across the rail cloth (and the surface cloth on rebound), neutralizing friction effects (older/dirtier/wetter vs. newer/cleaner/drier cloth), which are the most common things that change the "natural" rebound angle.

pj
chgo

 

[Oikawa]

A sliding CB with gearing running english avoids rubbing across the rail cloth (and the surface cloth on rebound), neutralizing friction effects (older/dirtier/wetter vs. newer/cleaner/drier cloth), which are the most common things that change the "natural" rebound angle.

pj
chgo

Interesting. With gearing outside, in this context, I assume you mean the amount of outside english that cancels throw out. Is that amount of english constant across different speeds? And more generally, do some other variables affect it than speed, or is it (the amount of sidespin for gearing effect) always the same no matter what?

 

[bbb]

A sliding CB with gearing running english avoids rubbing across the rail cloth (and the surface cloth on rebound), neutralizing friction effects (older/dirtier/wetter vs. newer/cleaner/drier cloth), which are the most common things that change the "natural" rebound angle.

pj
chgo

when a ball hits a rail nose at an angle isnt there friction between the two?
wouldnt that cause some "rubbing"
similar if the ball is touching the cloth surface even if sliding
isnt there friction between the ball and the cloth
wouldnt that cause some "rubbing"