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View Full Version : Cue ball deflection: 1 o'clock vs. 5 o'clock


JoeyA
03-14-2008, 01:44 PM
Another web site insinuates that there is less deflection happening with 1:30 English than there is with 5:30 English (High right vs. Low Right).

Anyone want to make any constructive comments on that one?

JoeyA

Da Poet
03-14-2008, 01:51 PM
Another web site insinuates that there is less deflection happening with 1:30 English than there is with 5:30 English (High right vs. Low Right).

Anyone want to make any constructive comments on that one?

JoeyA

More swerve at 1:30 might cancel things out.

I guess it depends how hard you're hitting the shot.


Edit- As I understand the difference between swerve and deflection, maybe in the strictest sense of the definition, deflection would be greater at 1:30 than 5:30. The only thing physically possible that can straighten out the shot more on the 1:30 shot than the 5:30 shot is the friction of the ball on the cloth, and I would define that as swerve.

BRKNRUN
03-14-2008, 01:58 PM
That is beyound stuff even I think about...

My guess would be that 1:30 english gets to a natural roll faster than 5:30 englsih reducing the amount of time the ball spends traveling "off line" or deflecting...

I would imagine combinations of ball velocity and amount of spin induced would have an effect on the end results.

Patrick Johnson
03-14-2008, 02:02 PM
Another web site insinuates that there is less deflection happening with 1:30 English than there is with 5:30 English (High right vs. Low Right).

Anyone want to make any constructive comments on that one?

JoeyA

Whether you hit above or below center you're just about always hitting downward on the CB at least a little (or at least producing "downward squirt"), so with sidespin you always get both squirt and swerve. You get more swerve when you hit downward on the CB above center than when you hit downward on the CB below center. More swerve looks like less squirt. It's actually less squirve.

pj
chgo

av84fun
03-14-2008, 05:12 PM
Another web site insinuates that there is less deflection happening with 1:30 English than there is with 5:30 English (High right vs. Low Right).

Anyone want to make any constructive comments on that one?

JoeyA

Deflection (squirt) and swerve that can reduce the effect of squirt are related but two very different things.

Squirt varies with the degree of offset for the vertical center while swerve varies (among other things but primarily) with the degree of cue stick elevation.

Since 1:30 and 5:30 are the same distance from the vertical center, squirt would be the same.

However, since 5:30 requires a more elevated cue...all other things being equal...there will be more swerve which will cause the CB to leave the "squirt line" dictated by the off vertical center hit.

So the END RESULT is that the effect of squirt will be partially or wholly offset by swerve but NOT because swerve is a component of squirt or vice versa...just like aircraft engine-induced thrust and air foil induced lift
are entirely different aerodymic componets but which can expand or reduce the END RESULT of the airplane's altitude.

All IMHO.

Regards,
Jim

icem3n
03-14-2008, 05:24 PM
Another web site insinuates that there is less deflection happening with 1:30 English than there is with 5:30 English (High right vs. Low Right).

Anyone want to make any constructive comments on that one?

JoeyA

You need to consider the speed as well for 1.30.

jsp
03-14-2008, 05:49 PM
I don't know about 1 o'clock vs. 5 o'clock, but it sure seems that I get the most deflection right before I go to bed.

Luxury
03-14-2008, 06:07 PM
Could it be that as the cue ball is trying to deflect the cue is trapping the cb for a milisecond and it isn't as free to "fly" as it is with hitting low English?

Sorry this is poorly written. Hope you get the point.

JoeyA
03-14-2008, 06:57 PM
Whether you hit above or below center you're just about always hitting downward on the CB at least a little (or at least producing "downward squirt"), so with sidespin you always get both squirt and swerve. You get more swerve when you hit downward on the CB above center than when you hit downward on the CB below center. More swerve looks like less squirt. It's actually less squirve.

pj
chgo

So you're agreeing that there is less cue ball deflection with 1:30 English than there is with 4:30 English, correct? Similar to the diagram below, correct? For Cuetable new users, there are two pages showing both the high right English and the low right English. You can click on the respective numbers in the lower right portion of the cue table to see both layouts and you can toggle back and forth to see the cue ball's final spot.

http://CueTable.com/P/?@4BAwH4PAWi4VAwH1VAvn4kAWi7kBCv7kBnH2kBtk2kBtk2qQ tFThe_blue_arrow_lines_show_the_aiming_line_using_ hight_right_English.&ZZ2uCEO@4ABFF4PAWi4UBFF1UBEj4kAWi7kBau2kDQk2qQtFTh e_colored_arrow_lines__show_the_aiming_line_using_ the_low_right_English.&ZZ1uCMM@JoeyA

JoeyA
03-14-2008, 06:59 PM
You need to consider the speed as well for 1.30.

Mezz cues, eh?
JoeyA

Poolplaya9
03-14-2008, 07:05 PM
I would think that the 1:30 english gives less deflection (squirt) than the 4:30 english simply because the 1:30 english imparts a bit of downward pressure on the cue ball which creates more friction between the cue ball and the cloth, and possibly even a momentary "trapping" of the cue ball under the tip not allowing it to move sideways. The difference is likely fairly minimal.

I also think the 1:30 english would cause more swerve because it imparts more downward force and lets the english "bite" into the cloth more, closer to what a masse would be than with the 4:30 english. I would not be willing to bet the farm on either though.

JoeyA
03-14-2008, 07:05 PM
More swerve at 1:30 might cancel things out.

I guess it depends how hard you're hitting the shot.


Edit- As I understand the difference between swerve and deflection, maybe in the strictest sense of the definition, deflection would be greater at 1:30 than 5:30. The only thing physically possible that can straighten out the shot more on the 1:30 shot than the 5:30 shot is the friction of the ball on the cloth, and I would define that as swerve.

Let's say this is based upon you hitting both shots with the same amount of speed, a medium speed stroke.

Have you ever read that a high right hit cue ball will deflect a different amount than from a low right hit cue ball, hitting with the same speed and the same aiming line?

JoeyA

12squared
03-14-2008, 07:16 PM
Joey,

Here's an article from Dr. Dave that discusses this very point. http://billiards.colostate.edu/bd_articles/2007/oct07.pdf.

Summary is that the squirt is the same for both, but swerve differs as one other poster wrote.

Hope this helps, Dave

Patrick Johnson
03-14-2008, 07:50 PM
So you're agreeing that there is less cue ball deflection with 1:30 English than there is with 4:30 English, correct? Similar to the diagram below, correct?

Yes, your diagram is right, but I'd say it differently. I'd say there's less "effective squirt" with high sidespin (because it's reduced more by swerve).

The extreme example of this is when the cueball is frozen to the rail and you hit it with sidespin. You get a surprising amount of swerve that way, often so much that you have to aim as if you're getting "negative squirt" (which, in effect, you are).

pj
chgo

av84fun
03-14-2008, 08:13 PM
Quote:
Originally Posted by JoeyA
So you're agreeing that there is less cue ball deflection with 1:30 English than there is with 4:30 English, correct? Similar to the diagram below, correct?



Yes, your diagram is right, but I'd say it differently. I'd say there's less "effective squirt" with high sidespin (because it's reduced more by swerve).


pj
chgo

Joey, Patrick and I have had this same dialog before. I am not being argumentative...such descriptions are a matter of personal preference and we end up at the same place regardless of the difference.

But I prefer your above description. Squirt and Swerve result from entirely different physics and I think should be understood and predicted seperately.

Similarly, as you know, you can widen the departure angle and increase CB travel on a draw shot where you impart running english as well as low draw.

But I would not like to refer to that as "effective draw." Rather, I would like to predict the departure angle and CB roll assuming centerline draw and then add running english as necessary to achive the wider angle and greater CB travel.

Again, just another way to think about getting to the same place.

Regards,
Jim

SPINDOKTOR
03-14-2008, 09:45 PM
Mezz cues, eh?
JoeyA


Something wrong with Mezz cues?

bluepepper
03-14-2008, 09:51 PM
Is gravity or inertia perhaps an issue? It feels like a bit more of a fight to get a draw shot in motion than a topspin shot. You feel the weight of the cueball on a draw.
Jeff

JoeyA
03-14-2008, 10:41 PM
Something wrong with Mezz cues?

No, not at all. I've exchanged PM's with the icemen3 before about different cue makers.. that's all.
JoeyA

JoeyA
03-14-2008, 10:59 PM
Joey,

Here's an article from Dr. Dave that discusses this very point. http://billiards.colostate.edu/bd_articles/2007/oct07.pdf.

Summary is that the squirt is the same for both, but swerve differs as one other poster wrote.

Hope this helps, Dave

I'll be darn. I have never read this one or if I did, it didn't stick. Thanks!

I have always been pretty good at using low inside or low outside English. My use of high inside or high outside English is not so good. I practiced for about 30 minutes tonight using a different aiming point of approximately 1/2" at five feet and have had excellent results.

While there may be some who don't care much about the physics of pool and simply play pool by instinct, this is a good example of how some of the physics guys can help your game.

I'm not going to start a poll as to how many people know that low side spin and high side spin require different aiming points on the object ball for it to be pocketed but I am curious. I never knew it and saw it on a cuemaker's website. I must have glossed over it on Dr. Dave's website. Sheesh...... Now I know why I've been missing a lot of balls trying to get three rail shape.

http://CueTable.com/P/?@3DXNV2PALT1QBBm1RCAE2kALT3kXFF1lBBm3lVqH1mCAE3mV RR2qQtFThe_red_line_indicates_the_aiming_line_usin g_high_inside_English.__The_blue_line_indicates_th e_aiming_point_for_using_low_inside_English.__This _is_using_my_particular_cue_and_yours_may_vary.__I _use_a_standard_Maple_shaft_at_this_time.__Knowing _this_piece_of_information_will_help_my_game.__Hop e_it_helps_yours.__JoeyA&ZZ4uBvJ@

JoeyA

JoeyA
03-14-2008, 11:06 PM
Is gravity or inertia perhaps an issue? It feels like a bit more of a fight to get a draw shot in motion than a topspin shot. You feel the weight of the cueball on a draw.
Jeff

Jeff, others may be able to answer your question better. It seems to me that it is easier to make a ball with slight draw than it is to make it with slight follow but we're talking about how high side spin and how low side spin require different aiming points and why.
JoeyA

av84fun
03-14-2008, 11:12 PM
I've know it for some time Joey but that's only a portion of the battle. The PROBLEM is that SO MANY cueing issues vary with the amount of deviation from centerball on ALL radials from the center and also vary with the force applied to the shot.

The variations are almost infinate and mastering them (as much as humanly possible) is THE major difference between the great champions, the short stops and the rest of us.

Whenever you see a champion dog a shot and get that "deer in the headlights"..."WTF HAPPENED" look on their faces, the odds are that there was SOME miscalculation of one of those cueing variables because they DO know how to set up, aim and stroke.

One of the BIG issues for most of us amateurs who play mostly with balls that aren't in as new condition and are therefore subject to greater Spin Induced Throw, is judging the amount of SIT that will happen on slowish shots and try to balance that off against any squirt or swerve that will also be factors.

Sure is an issue for me at least.

Regards,
Jim

Jal
03-14-2008, 11:16 PM
While I think the explanation for less apparent deflection at 1:30 being due to more swerve is correct, there's been a bit of ambiguity in the way the term "more swerve" has been used.

Given shots hit at 1:30 and 4:30 with the same cue elevation, the one at 4:30 will produce a greater swerve angle if the cueball is allowed to attain natural roll before colliding with something. This will be even more so if the stick has greater elevation for the draw shot (4:30), which is usually the case.

However, swerve "takes" sooner at the 1:30 position. To see why you need to do a little geometry; it has to do with the surface speed components and how they add up to produce the direction of the friction force against the cloth. In this sense, swerve from the follow shot has a greater overall effect since it takes place more early on in the cueball's path. If allowed to though, the draw shot path will cross the follow shot path and end up at a greater angle from the cueball's initial direction.

The larger bounce that you get from hitting above center also has something to do with it, but is relatively minor I believe.

Jim