Does it help to elevate the cue for draw shots?
It depends. Firstly, if the CB is close to a cushion or another ball, the only way to get the tip low enough on the CB is to elevate the back of the cue (i.e., “jack up”).
Cue elevation can help create quick draw with shots at an angle. However, with straight draw shots, there is no physical benefit to elevating the cue. See physics-based draw-shot advice for more info. Not only is physics a problem with elevated-cue draw, reduced accuracy and unintentional swerve can also be factors. Also, with cue elevation, the CB will hop more, which can result in overcutting a shot per jump shot over cut effects.
Now, it is possible that elevating the cue might cause a player to do something different with the amount of tip offset from center or with the stroke. Elevating the cue might help some people hit the CB further from center than they think. A possible reason for this is that for a given tip contact point, the effective tip offset from center is greater with more cue elevation. The following diagram from “Draw Shot Physics – Part IV: cue elevation effects” (BD, July, 2009) illustrates this effect:
Also, when some people elevate the cue, they might accelerate the cue differently, creating more speed at CB impact, which could create more draw.
Now, if a person has large fingers and hands and uses a closed bridge (especially if the closed bridge is high), extra cue elevation might be required to get the tip low enough on the CB, especially if the bridge length is short. Also, if a person tends to drop their elbow during or after the hit on the CB, extra cue elevation might help avoid a collision of the grip hand with a rail or the table surface.
For more information, see cue elevation effects and technique advice.