I mean, you need to elevate in order to bend the cueball. So why would this not also apply to Object ball?
It does apply to the object ball with a slight (very slight) caveat. In theory, you can cause the OB to curve by applying either draw or follow to the cueball (without jumping) at any non-zero cut angle. This is because the CB-OB contact time, though brief, is not zero, and thus the induced surface rotation of the OB is not quite aligned with its forward translational motion. Depending on whether you've imparted topspin or backspin, it'll curve one way or the other. But the effect is negligible.
As far as curving from pure sidespin (vertical spin axis), Dr. Dave has a video that demonstrates that it doesn't to any noticeable degree (except maybe when it's near a complete stop?) Bob Jewett, at one time, offered a cash reward to anyone that could show that it actually occurs.
If you want to bend the OB, you need to hit it above center. But if you jump the CB to hit the OB from above, it will not be traveling fast enough to induce curve, because it will essentially be falling from the sky as it strikes the OB. Not hard enough to cause a curve.
I'll have to side with the yeas on this, but I agree with the spirit of your statement. You can't produce a heck of a lot of curve, but it isn't necessarily negligible. This may be a little vague, but as a rule of thumb, if the CB contacts the OB at a "latitude" of 45 degrees (halfway up its surface from horizontal equator to north pole), and induces a crosswise spin corresponding to x degrees of throw (however that's accomplished), the difference in direction between the OB's initial velocity immediately after impact and before even the first bounce, and its final roll velocity after it's settled down, will be x degrees. (This is apart from the throw itself. Throw angles range from zero to about five or six degrees.) If contacted at a higher latitude, the difference in direction, given the same magnitude of throw/spin, will be greater (it'll curve more). If contacted at a lower latitude, it'll curve less.
At a latitude of 70 degrees, for instance, with an induced cross-spin corresponding to 3 degrees of throw, the difference in direction (initial to final), works out to about 8 degrees. But because of the large reduction in horizontal translational velocity, roll will commence after only a very short travel distance. Once roll begins, curving ends.
I guess the moral is that it's not a very practical way to get around interference. But then that's probably not news to anyone.
A complication which may invalidate some of the above, is that at high latitudes you're driving the OB down steeply into the cloth. For normal shots where, for instance, friction from topspin does the same thing, it's not really a factor since the force is relatively small. But it could very well be one here.
Jim
