I just wrote this same question on a comment thread I have on youtube on Dr. Dave's latest draw shot video. I'll ask it here as well.
'Here is an interesting experiment I just did. I wiped all of the chalk off of my both my bk rush break cue (quarter shaped tip) and my jacoby black playing cue (dime shaped tip). When I attempted a draw shot with the bk rush I scooped the cue ball. But when I attempted a draw shot with the jacoby black cue, I miscued but without the scoop. I just ended up with a real weak hit and that miscue sound. Just wondering what your thoughts on this was?'
'Here is an interesting experiment I just did. I wiped all of the chalk off of my both my bk rush break cue (quarter shaped tip) and my jacoby black playing cue (dime shaped tip). When I attempted a draw shot with the bk rush I scooped the cue ball. But when I attempted a draw shot with the jacoby black cue, I miscued but without the scoop. I just ended up with a real weak hit and that miscue sound. Just wondering what your thoughts on this was?'