Ask The Master - Is there such thing as draw-induced throw? I'd swear that the object ball is being thrown on my crisp draw shots, but I must admit that my aim suffers on my crisp shots.
A: Throw effects vary with cut angle, speed, cueball rotation, and ball friction at the moment of impact with the object ball. In the range of typical cut shot angles (say 20 to 50 degrees), you actually get more throw with stun than with draw or follow. On thin cuts, draw doesn't matter.
But for thick cuts, I think it's a bit more complicated. Starting with the thickest of the thick cuts – straight in – draw encourages the OB to roll immediately (or at least sooner than it otherwise would). But without a cut angle and without sidespin, there is no throw.
Now let's consider the same shot, but with a slight cut angle. The OB is cut on the angle of the ball centers, but if the OB has some roll right away, it could curve forward a bit relative to the cut line. The roll direction is a little forward of the cut line. This would behave like throw in that it would in effect reduce the the cut angle.
Throw is caused by the rubbing friction between the balls at impact. Backspin on the CB rubs upwards on the OB, causing roll in the direction of the spin. So, is it throw? The technical answer is debatable, but my pragmatic answer is yeah, kinda.
Another factor that could be at play here is the fact that draw is much more difficult to hit accurately. A sliding or backspinning cueball will curve if you don't hit perfectly on the vertical axis of the ball. A purely rolling ball will not curve. Further, you have to hit harder for draw, bringing a host of extra problems – stroke breaks down, stick swerves, speed control falls off, draw hard to judge, possible miscue, elevated butt, etc. Hard to tell for sure what happened.
One more possibility here is that draw drags on the cloth and slows the cueball. As the CB speed decreases, OB throw increases. So if you're considering typical cut angle shots, where collision-induced throw is a significant factor, what looks like "more throw" could be due to the slower speed.
Moral of story? Roll your cueball whenever you can. Hit softer. Take extra care to be precise when you're hitting draw. It's way more sensitive than roll.
Throw is real, and must be dealt with. Top players work to eliminate or neutralize throw effects when they can, as fewer variables yield fewer ways to screw up the shot. To learn more about how to reduce the effects of throw and increase your accuracy, send me an Email me and ask for a copy of my article "Throw Out the Throw."