Official
Fergal O'Brien Website
Screwback
Most people think there is some trick to screwing
the ball back,
or that they have to do something new or extra to get screwback.
That is absolute nonsense.
To screw back you must hit the cue ball at
the bottom
but you must keep the cue as parallel to the cloth as possible
and deliver the cue SMOOTHLY and the white will
come back
(you may have to lower your bridge hand as you do not want to hit the tip
of the cue
digging down at an angle to the cueball).
It is essential that you hit the cueball straight,
but below centre, and not come down on the cue ball.

How much screw you can get on the ball depends on how hard you hit the cue
ball,
how smoothly you hit the cue ball and the distance you are from the object
ball.
Remember to CHALK YOUR CUE.
There can be a lot of fear in players when attempting a screw shot
because they themselves have chipped the cue ball over the object ball,
or they have seen somebody else do this and they don't want a repeat performance
or they might even be afraid of ripping the cloth.
This fear leads to players using a poorer cue action than normal.
What is normally slow, smooth and controlled ends up quick,
anxious and jerky. This is a recipe for trouble.
To practice this you should put the blue on
its spot and place the white just off centre in the middle of the table.
Pot the blue into the middle pocket and try to screw back.
People often practice this shot and try to screw the cue ball back into the
middle pocket beneath them.
This is a very bad practice routine as it makes you move your bridge hand,
get up off the shot too quickly (so you cannot see any errors) and rush your
shot by snatching at it.
This all promotes anxiety in a player, leading to poor cue action
as the player is preoccupied with getting out of the way of the
cue ball coming back towards them, rather than playing the shot properly.
By making the shot off-straight, the player
can, with confidence,
deliver the cue smoothly and stay down on the shot with no fear of the cue
ball
striking them on the way back.
The above method develops a good cue action
and confidence (free from fear and anxiety).
Experiment by seeing how much backspin you can get depending on how hard you
strike the cue ball.
Regardless of how hard you hit the cue
ball the shot must always be smooth.
Let the cue do the work.
I recommend bringing the cue back an extra
inch or two (closer to your thumb),
when playing a screw shot, before you deliver the cue.
This will give you more control and extra power.
People tend to lift their head or move their
whole body (especially the elbow) on a shot like this, to try and generate
backspin.
This is not advisable or necessary.
To summarise. Let the cue do the work. Cue
smoothly and slowly.
After you have delivered the cue smoothly, stay down on the shot
and if you have hit below centre and straight on the cue ball you will get
backspin.
It's as simple as that (believe me).