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Seven Steps for Calculating a Benchmark Layout:

A guide for finding benchmark layouts from combined Dual Angle Ratio Guide & from Dual Angle Sweet Spot Guide (wiki articles.)

You will need to find the bowler's specs (there are many techniques and videos available in the wiki).

  1. to find Benchmark Total Sums.
  2. to find a Benchmark Ratio.
  3. to choose a Pin to PAP distance


Find Your Benchmark Total Sums (primarily using speed/rev relationship)

Step #1- Determine the Initial Sums of angles (drilling angle + VAL angle).

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 (off from step #2 for very high or very low tilt & rotation).

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

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

For these 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.

Step #3-Understanding Sums of the Benchmark Range (neccessary for calculations)

The Benchmark Range is necessary for adjusting other layouts off from the benchmark layout so the bowler will not have to change their specs when playing various conditions (Long & Strong layout/Control layout/Mid-lane layout/Totally Strong layout/ etc).

Total sums (drilling angle + VAL angle) determines the length of ball motion until the roll phase. (See: Three Phases of Ball Motion)

Note: The total sums of your sweet spot will include a (+ or - of degrees) which is the benchmark range.

  1. 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)
  2. Subtracting these degrees from your total sums will decrease the length of ball motion.
  • ± 30° for elite bowlers
  • ± 20° for good bowlers
  • ± 10° for average bowlers


Sweet spot of 100º sums using (± 20º) for this example.

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

  • Use a high ratio for long and strong layouts... (longer and quicker reaction to the dry...more of a skid /snap ball motion).
  • Use a low ratio for control layouts...(slower/smoother reaction to the dry)

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

  • Use a high ratio for Totally Strong Layouts... (defined/sharp motion...quicker reaction to the dry)
  • Use a low ratio for mid-lane layouts...(earlier/slower reaction to the dry...smoother & more continuous ball motion.)

Find Your Benchmark Ratio (by primarily analyzing tilt and rotation)

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

For examples on how to do the math, see simple math examples.

Step #4-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 #5 - Adjust the Initial Ratio (from Step #4 If bowler has 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 #6 - Find The Ratio Range (for calculating Long & Strong/Control/Mid-lane/Strong oil/Etc. layouts)

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 easier THS wet / dry patterns for more control and mid-lane reaction
  • Mo frequently uses the higher ratio range (a defined break shape) for flatter or more demanding patterns to create a stronger reaction to friction.

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.)

  1. Adjust the angles (ratio) for the design of the ball.
    1. Mo will usually raise the ratios on balls which tend to roll early.
    2. Mo will usually lower the ratios on balls which tend to be skid/flip.
  2. Adjust the angles for the pattern the bowler wants to use the ball on.

Pin to PAP distance will determine the amount of flare

Step #7-Choose the Pin to PAP Distance (for desired flare or desired amount of tilt & rotation retention)

Track Flare Chart

Track Flare Discussion:

High tilt players use Pin to PAP distances of 4 1/2" to 5 3/4" (with Asymmetrical balls)

  • 4 ½” Pin to PAP distance will make the ball come off the spot hard (more angular)
  • 5 ¾” Pin to PAP distance will make the ball roll forward sooner

Asymmetrical Balls exhibit most flare at Pin to PAP distances of 2 3/4" to 6 1/4"
Symmetrical Balls exhibit most flare with Pin to PAP distances of 3" to 4"

Retaining Axis Rotation & Axis Tilt (increase skid, reduce flare):

  • To retain Axis Rotation and Axis Tilt in SYMMETRICAL equipment, we would tend towards longer pin-pap (> 4") distances, while ASYMMETRICAL equipment we use shorter pin-pap distances (< 3").

Burning Off Axis Rotation & Axis Tilt (decrease skid, increase flare):

  • To burn off Axis Rotation and Axis Tilt quicker in SYMMETRICAL equipment, we would tend toward Max flare pin positions (3" - 4"), while longer pin distances (4"+) in ASYMMETRICAL equipment.

Roll the ball

Step #8-Use Balance Holes (if desired)

With some extreme specs, the benchmark layout will include balance holes because the bowler will want balance holes in the majority of their equiptment.

  • Start with a smaller size hole (3/4") at least 2-1/2” deep
  • P1 hole = Reduces drilled dynamics
  • P2 hole = Maintains drilled dynamics
  • P3 hole = Increases drilled dynamics some
  • P4 hole = Increases drilled dynamics more
  • (This is a very basic interpretation of the Gradient Line Balance Hole technique. Please visit wiki sites for more detailed information.)