 ## Strokes Gained 18  (SG18)

We have adopted a new and improved system for scoring putter performance.  This system is the most accurate way to test player putter efficiency.  Rather than measuring radial accuracy, we are measuring the actual putts required to put the ball into the hole.

We compare our test putters using the Strokes Gained Putting system developed by Columbia Business School professor, Mark Broadie.

While this system may have been developed by a college mathematician, it is actually very simple. We assessed the individual putters using the following process:

• Testers putted five times from 5, 10, and 20 feet, each time continuing to putt until the ball went in the cup.
• The average number of putts from each distance for each putter was then calculated.

(Total Putts for Cohort)/(50 “Holes” at each distance)= Ave. Number of Putts/”Hole”

• The average of all putters at each distance was then calculated in a similar fashion.
• The strokes gained at a given distance was then calculated by subtracting the putter cohort average from the tester average for an individual putter.

(Average Putts for Individual Putter) – (Average for All Putters) = Strokes Gained vs. Average

• This means that a putter with a positive score scored better than the average, while a negative scoring putter scored worse.
• To calculate the final score, we added up the individual strokes gained for the three hole distances, then multiplied them by six to give us a strokes gained score that would reflect using the putter for an eighteen hole round of golf.

## Testing Parameters

• Number of Testers: 20
• Testing Handicap Range: +3-18
• Testing Location: MyGolfSpy Test Facility
• Ball Used: Bridgestone 330-RX
• Distances Assessed: Five, Ten, and Twenty Feet
• “Holes Completed” at each Distance: 6
• Total Putts in Test: 9,000