Just putting the pin "under the thumb" only inverts the bowtie and causes the ball to flatten out downlane. Mainly because of these two factors:
1) Distance of the pin to your N.A.P.
- Yes... the negative axis point. If you have a very low track, that pin is probably 7-8" from your NAP being right under the thumb. It's going to lower the flare and overall hook a lot.
2) The pin being that much below the center of grip
- This will pull your bowtie down near the thumb and greatly decrease the entry angle as the ball will break tilt the earliest and roll the most forward as it exits the pattern
That layout posted will work best with a higher track, high rev player as long as the pin is 5-5 1/2" from the Negative Axis Point. If you're hellbent on trying the layout, I would plug it and move the grip so that the pin is closer to 7-8 o'clock or wherever the layout falls in order for the pin to be 3 1/2" below the centerline and 5" from your negative axis point.
Try that and the ball will roll much better, I promise.