Dual Angle Ratio Guide

'joint effort from Elgavachon/Athery'

ratio discussion

Mo once told us "Determine the ratio of the angles to determine the shape of the ball motion. Axis rotation and axis tilt affect this decision a lot."

Mo more recently said " Once you decide on the ratio, the rest is math". Here is a chart Athery has done to help with finding the ratio and a range of ratios to do that math.

to obtain approximations of ratios (based off various of Mo's recommendations)

After you have calculated the total sums and before you can calculate the benchmark or sweet sums, it is necessary to find the benchmark ratio.

This is necessary To accurately calculate the drilling angle and the val angle individually. . The middle column (Initial Benchmark ratio) gives some examples of of approximate ratios sometimes used by Mo for speed/revs matched + normal rotation.

CHART IS BY ATHERY

speed or rev dominance and/or extreme high or low rotation

In case of a conflict between speed or revs and rotation, go with the ratios which correspond to the rotation.

Higher speed dominance and/or extreme high rotation=decrease ratios.
(adjust to boxs further right on the chart)

Higher rev dominance and/or extreme low rotation= increase ratios.
(adjust to boxs further left on the chart)'

example # 1

20* tilt with very speed dominant and high rotation, the initial ratio would have been 1:1. The new adjusted benchmark ratio will be 1:1.5 (SEE CORRESPONDING COLUMN ON CHART) with a new ratio range 1:1 to 1:2 (range is an example only).
example # 2

20* tilt with very rev dominant and low rotation, the initial ratio would have been 1:1. The new adjusted benchmark ratio will be 1.5:1(SEE CORRESPONDING COLUMN ON CHART) with a new ratio range of 2:1 to 1:1(range is an example only).

The 1:1 corresponds to rev/speed matched (center column). Higher rotation with speed dominance will move the BENCHMARK RATIO 2 columns to the right or to the 1:1.5 ratio box. If you wanted to use +or-.25 for your ratio range, go 1 box to the right and 1 box to the left while looking at your RATIO in appropriate column on the chart. You would have a narrow range of 1:1.25 to 1:1.75 (easy to see) Using the same example: If you wanted a +or- range of .5, your new ratio box for 20* tilt with speed and high rotation is 1:1.5 but you want a larger ratio range, go 2 boxes left and 2 boxes right while viewing table and your ratio range is now 1:1 to 1:2.

Another example would be a 10* tilt bowler speed/revs matched in center column has a 2:1 ratio. If you wanted a ratio range of +or- 1, you would go 4 columns to the right and 4 columns to the left and have a RATIO RANGE of 3:1 to 1:1 A 10* tilt bowler who is up the back would have a 2.5:1 ratio on this chart so the open boxes will allow a range of 3:1 to 2:1. The colored corners lets you know you are out of the recommended 3:1 or 1:3.

You would adjust this based on the amount of dominance.

Mo very seldom gives an extremely large ratio range. It is more common with very low or very high tilt. A +or- of around .5 above or below benchmark ratio seems to be close to average ratio range.

Further Notes

You need this adjusted ratio range to utilize in conjunction with your total sums to accurately calculate your sweet sums. Your adjusted ratio range would be used with the +or- total sums to mathmatically calculate long pattern and short pattern layouts. Mo frequently uses the lower ratio range for control drillings for easy conditions or wet/dry. He frequently uses the higher ratio range for more challenging conditions.

Please note; These are our ideas for a basic starting place. You would adjust for specific balls,condition specific reactions,extreme conditions, etc.