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To find your personalized Benchmark Layout you will need to follow the steps to find the following:

  • ...Find your specs.
  • ...Find your Benchmark Total Sums.
  • ...Find your Benchmark Ratio.
  • ...Choose a Pin to PAP distance

Bowler Specs Affecting Dual Angle Sweet Spot

  • Ball speed
  • Rev rate
  • Axis tilt
  • Axis rotation

Finding Your Benchmark Total Sums

STEP #1... Find Initial Total Sums analizing Speed/Rev Relationship

Start your calculations by finding the relationship between ball speed and rev rate. An example of a well matched bowler would be 17mph speed and 300rpm (off the hand). For each 1mph increase or decrease in speed, a corresponding increase or decrease of about 50rpm would stay matched. Bowlers who are speed/revs matched would start their calculations with 95* of sums. Link Text

Rules of thumb:

  • For the first 50 revs of imbalance (in excess), add 10* to the Total Sums.
  • For the first 1 mph of speed imbalance (in excess), subtract 10* from the Total Sums.

If the speed/revs imbalance is extremely high or low, you would add or subtract extra sums to compensate accordingly. The amount of sums you add or subtract is not linear (for the second 50 revs of imbalance, you will add or subtract less than 10*, etc.)

STEP #2...Adjust Initial Sums (of step #2) for very high or very low tilt & rotation.

Mo will also lower the sum of angles for those with very high tilt & rotation, or raise the sum for those with very low tilt & rotation.

For tilt adjustments, we are using 13* to 17* of tilt as the normal tilt range.

For rotation adjustments, we are using 45* to 60* of rotation as the normal rotation range.

Rules of thumb:

  • Lower totals by about 10° for high tilt
  • Raise totals by about 10° for low tilt
  • Lower totals by about 5° for high rotation
  • Raise totals by about 5° for low rotation

If the tilt or rotation is extremely high or low, you could add or subtract extra sums to compensate accordingly.

Adjusting off your Benchmark Total Sums (symbiotic layouts for your specs)

Total sums determines the length of ball motion until the roll phase (See: Three Phases of Ball Motion)

  1. Degree of drill angle + degree of val angle = Total Sums.
    1. Note: The total sums of your sweet spot will include a + or - degrees.
  2. Adding these degrees to your total sums will add length to the ball motion. (increasing total length of ball motion before reaching the roll phase)
  3. Subtracting these degrees from your total sums will decrease the length of ball motion.


Sweet spot of 100º (± 20º)

For dry or short oil patterns to increase' length, use 120º sums.

  • Use a high ratio for long and strong layouts.
  • Use a low ratio for control layouts.

For oily or longer patterns to decrease length, use 80º sums. (utilizing ratios to achieve the desired break shape)

  • Use a high ratio for defined/sharp motion.
  • Use a low ratio for mid-lane roll.

Finding Your Benchmark Ratio

This is necessary to accurately calculate the drilling angle and the val angle individually.


  1. Find initial tilt ratio (see table below).
  2. Adjust this ratio higher or lower according to your axis rotation.
    1. Move box to left or right on chart. Extreme speed or rev dominance can accentuate this which requires more of an adjustment.
    2. If there is no (primary ) adjustment necessary for high or low rotation, you do not need to adjust for speed or rev dominance (secondary)
  3. Calculate the ratio range.
    1. This is necessary to mathematically calculate your personal desired ball motions/layouts. (control, long and hard, mid-lane, strong oil, etc.)
  4. For examples on how to do the math, see simple math examples.

Step #1 - Find The Initial Ratio From Axis Tilt

The middle column (initial ratio benchmark range) gives approximate ratios for bowlers with speed/revs = matched + normal rotation.

Please note: when creating the chart we used 50º to 55º as normal axis rotation. (45º is slightly low and 60º is slightly high)

  • For axis tilt below 7º (especially when accompanied by high rotation) use this PDF chart.
  • For axis tilt below 7º accompanied by low rotation use the chart below:
  • For low axis tilt with very low revs use the chart below (even with high rotation):

Chart created by Athery Ratiochart.png

Special notes for axis tilt below 7º: With low tilt, the rotation seems to effect the ratios a lot more than with medium tilts. A high rotation will decrease them a lot (what Mo calls PDW territory) and a low rotation will significantly raise them. There is more of an extreme adjustment comparitively. The ratios increase as the tilt decreases until you reach below 7º to 10º; below that the ratios decrease. Part of the reason is because the maximum drilling angle is 90º and with low tilt, you need ratios which will take the ball down the lane. Here is a PDF chart on how to adjust Athery's chart, especially when low tilt is accompanied by high rotation.

Step #2 - Adjust For High Or Low Rotation

Amount of adjustment necessary depends on the relationship between rotation and ball speed.

  • High rotation and/or high rotation accentuated with speed dominance = decreased ratios (use boxes further right on the chart)
  • Low rotation and/or low rotation accentuated with rev dominance = increased ratios (use boxes further left on the chart)

Step #3 - Find The Ratio Range

The maximum ratio and minimum ratio (drill angle and val angle) which should be utilized with your personal sweet sums is defined as your ratio range. This is how far you can deviate your ratio both higher and lower from your benchmark ratio. It can be calculated by choosing boxes left and right of your chosen ratio on the chart above. Mo very seldom gives an extremely large ratio range. It is more common with very low or very high tilt. A +/- of around 0.5 above and 0.5 below benchmark ratio seems to be close to the average ratio range.

You need to determine your personal ratio range to use in conjunction with your total sums to accurately calculate layouts for your personal specs or sweet spot.

  • Mo frequently uses the lower ratio range for control layouts, and easier lane conditions.
  • Mo frequently uses the higher ratio range (a defined break shape) on more challenging lane conditions.

Please note: On ratios less than 1:1, Mo sometimes expresses ratios with the val angle reduced to :1 example: 1:1.25 would be expressed as .8:1 (.8:1=1:1.25, etc.)

Ratio Discussion

Ratios determine the balls break shape.

  1. The drill angle helps determine the length of the skid phase of ball motion.
  2. The val angle helps determine the length of the hook phase of ball motion.
  3. The drill angle + val angle = the total length of ball motion before the ball reaches the roll phase.
    1. A higher ratio of the drill angle to the val angle = longer and quicker reaction to the dry. (more of a skid /snap ball motion)
    2. A lower ratio of the drill angle to the val angle = earlier and slower reaction to the dry (smoother & more continuous ball motion.)