oooooh. selby has missed the blue.

i like plants. always look for them

The plants can be missed though, ;)

Piokermonster. I can't accept your statement that the cue ball, if struck centrally, will start to rotate immediately. This is not possible. If the ball is propelled by the cue it will move in the direction it is struck at a speed relative to the energy imparted. Any rotational effect can only come from the friction generated by the bottom of the ball against the baize. The ball MUST move horizontally immediately and the rotation will increase from zero (skidding) to 'normal' by the effect of the aforementioned friction. To observe this you need to view footage from a high-speed camera using a striped target ball. You will not be able to see the effect on a plain ball.
'Topspin' is what occurs when some, perhaps all or even an excess of this rotational component is applied by the striking force (the cue). The amount of rotation applied would depend upon the point of contact, peripherally and the angle at which it was applied, from horizontal to vertical.

do you mean it is spinning forwards as well as rolling forwards naydam? like it spins backwards when you use screw? I thought that at first but that doesn't seem to be true.

Sure it can. If you cue vertically down there would be NO directional energy but the ball would spin. Then all of the horizontal movement would come from this rotation. A bit like the 'Masse' (?) shot.

I've read most of it. But the point I picked up on particularly, was the remark that the ball starts spinning immediately. That can only be incorrect. The rotation comes from the baize or the cue, or both.
As stated, this would be best viewed on specialist gear as it is difficult to see in real-time with a plain ball.
It might help to visualise the events on a different surface. Ice for example, where the frictional component would be much reduced.

naydam - where does it say it starts spinning immediately? i've just read through again and can't find it, unless you mean where it says it rolls immediately, but i don't think that is the same thing. it i very confusing.

naydam 25 Apr 15:59

Pokermonster. I can't accept your statement that the cue ball, if struck centrally, will start to rotate immediately. This is not possible. If the ball is propelled by the cue it will move in the direction it is struck at a speed relative to the energy imparted. Any rotational effect can only come from the friction generated by the bottom of the ball against the baize. The ball MUST move horizontally immediately and the rotation will increase from zero (skidding) to 'normal' by the effect of the aforementioned friction. To observe this you need to view footage from a high-speed camera using a striped target ball. You will not be able to see the effect on a plain ball.
'Topspin' is what occurs when some, perhaps all or even an excess of this rotational component is applied by the striking force (the cue). The amount of rotation applied would depend upon the point of contact, peripherally and the angle at which it was applied, from horizontal to vertical.


Good morning Naydam. Thank you for your interest, sir.

I don't believe I would have said if the cueball is struck centrally it will start to rotate immediately, because this is not he case. If the cueball is struck ABOVE centre it starts its natural forward roll immediately. Struck in the centre, or anything below this point, and it will certainly SLIDE for some time before the friction between cloth and ball causes it to roll.

Topspin, if defined as some sort of overspin akin to a dragster spinning its tyres in the same direction as the car is moving is impossible to action on the white with a cuestick. The coefficients of friction (between the phenolic resin of the ball and the wool of the cloth) are too great to overcome under normal match conditions. You can sometimes achieve it with the palm of your hand, but not with a cue.

Thank you again, sir. :)

Hi chaps. It could be that it said 'rolls immediately'.
To be honest, I'm losing the gist of the whole thread and 'who said what etc'. The expression 'topspin' is probably a misnomer. however, if one cues vertically down onto the ball and this causes horizontal movement of the ball, then that would be 'Topspin' although it was not actually applied to the top of the ball if expressed in relation to the table. I suppose you might well say you struck the 'front' of the ball.

Hi Naydam. :)

When you say "strikes down vertically" do you mean akin to attempting a massé strike. sir?

If you do this will not action topspin in the sense the cueball is spinning over and above the direction it is rolling. Essentially, it is spinning in the opposite direction to which it is rolling.

Newton's (3rd) law of motion sucks balls

and thus the advancement (enhancement) of natural motion.

Did you know if a pool ball is sliding when it hits another ball it deflects from it at a ninety degree angle?

You can quickly prove this using Einsteins theory of relativity and Pythagorus's theorum. Incredibly useful if you're a player, too.

I'm slighty confused as to your meaning Naydam, sir. But I believe what you describe would be considered backspin, not topspin.

Essentially, Mavis, I was arguing that the cueball cannot spin in the same direction as it is rolling. When one plays a screw stroke the white spins in the opposite direction to which it is travelling. But when one plays a topspin stroke, it just rolls.

It is quite difficult to convey in words, sir. Sorry.

so force/power etc doesnt come into it?

beaucoup de poissons (funnily enough)

Canard, Rodney

Hell-fire! It's late. I'm off to bed,. G'night chaps. :-)

Force, or momentum, is definitely a factor of course Dave, but the salient point to realise is that it is impossible to create sufficient force (with a cuestick at least) to overcome the friction between pool ball and cloth that would be required to set the cueball spinning over and above its natural forward roll.