Distance Per Shot: A Closer Look at the New Calculation in the SI World Golf Rankings
Last week SI launched its new SI World Golf Rankings, a data-driven list powered by Golf Intelligence. The calculations include new metrics to rank the best players in the world across all tours. This week we unveiled a new online home for the list with improvements to the user interface. In the weeks ahead we’ll go beyond 100 in the rankings and roll out a women’s ranking.
To better compare pro golfers across all pro tours, Golf Intelligence, our data partner on this project, created a new calculation: Distance Per Shot (DPS) with a "Dynamic Course Adjustment." In this article, we’ll further explain DPS and Dynamic Course Adjustment and how each are used in the SI World Golf Rankings.
Why Use DPS in the SI World Golf Rankings Instead of Strokes Gained Total?
Course distance matters. The OWGR doesn’t include distance in their Strokes Gained Total calculations. SI and Golf Intelligence incorporate distance as an important metric to create the SIWGR. DPS, combined with Dynamic Course Adjustment, is an objective calculation that factors in course length and difficulty. Plus, any golfer can understand it.
The SIWGR follows the same methodology as the World Handicap System (WHS), instead of Strokes Gained Total. The WHS is used by about 15 million golfers worldwide to maintain a handicap to play in competitive events. WHS uses a percentage of a golfer’s last 20 scores based on differential, a calculation that blends a golfer’s handicap index, course rating, slope rating and playing conditions adjustment.
The Dynamic Course Adjustment used in the SIWGR uses thousands of historical scores from each course to account for difficulty. SI uses the best of the latest 40 scores, course-adjusted, to calculate the player’s DPS for the SIWGR. SI and Golf Intelligence believe DPS is the best way to rank all golfers around the world because it uses the lowest common denominators for every round of golf: distance played and score.
Here's a summary of the main calculations being used to rate and rank the golfers in the world:
- Distance Per Shot (DPS): A formula to rank all the golfers in the world while using scores and distance information. To account for course difficulty, DPS uses Dynamic Course Adjustment.
- World Handicap System (WHS): Uses scores and manually collected course ratings that are primarily used for competitive play.
- Strokes Gained (SG): Used by professionals and gamblers to identify strengths and weaknesses of a player's game. SG is calculated by capturing detailed shot distance and surface information of every shot.
- Strokes Gained Total (SGT): Used by the OWGR to summarize all professional golfers using only score and course data information, but no distance. OWGR uses regression and simultaneous equations to calculate Strokes Gained Total.
So, What is the Difference between Sports Illustrated’s Distance Per Shot and the OWGR’s Strokes Gained Total?
SIWGR’s DPS is using scores, distance, and course adjustments. The OWGR’s SGT uses scores and course data. Both organizations’ rankings are accurate, but use different approaches to get their rankings. There are always multiple ways to accomplish a data-driven task.
The players ranked in the SIWGR Top 100 list are not dramatically different from the current OWGR rankings, even with a completely different method of calculating each event. For example, both the OWGR and the SIWGR had Jon Rahm passing Scottie Scheffler for No. 1 after his win at Riviera. Most golf fans would agree that Rahm is the best player in the world at this moment.
With the goal of including all pro events and amateurs in the SIWGR, our partners at Golf Intelligence are bringing their experience from the handicap system to let the data tell the story with a simple to understand calculation that works for all golfers.
The Elements of the DPS Ranking
Now let’s take a closer look at how SI calculates DPS:
On the surface, distance per shot is simple—it’s a golfer’s total score divided by the course yardage. So, a round of 70 at a 7,000-yard course would be a base DPS score of 100. To account for different degrees of course difficulty, the SIWGR formula also includes a Dynamic Course Adjustment because not all rounds of 70 on 7,000-yard courses are created equal. Golf Intelligence has proprietary data on thousands of courses and actual player results that allocate points for better play on more difficult courses. Distance Per Shot is a new data point for the golf ranking community, but it’s a smart way to evaluate play, and as people study it, we think they'll agree.
Distance Per Shot (Player DPS)
- Data collection includes the golf course and the tees played. Professional players usually play from the longest set of tees and amateurs will select tees based on their ability. Associated with each set of tees is the yardage per hole and the total yardage of all 18 holes.
- Once the round is complete, scores are recorded along with the tees (yardage) played.
- Golf Intelligence will use the yardage played divided by the total score to calculate the golfer's DPS.
How many scores are used?
- For a golfer to be “current,” the golfer must have 20 scores within the past year.
- A max of 40 scores will be used within the past year.
- The best 40% of those scores will be used to calculate the golfer’s DPS
Individual Course DPS
- Each course’s DPS is calculated for each set of tees and yardage.
- Golf Intelligence has a large database of golf scores and we use the scores to determine the course DPS for each course and set of tees. So for example, GI will have 1,000 scores that have been played from the “white” tees that measure 6,300 yards. GI will use the best 750 scores and take an average to calculate the course DPS for play from the white tees.
Dynamic Course Adjustment
- The Dynamic Course Adjustment is used to adjust DPS values to balance hard and easy courses.
- Golf Intelligence has historical data for each course for each set of tees. Golf Intelligence then uses that data to calculate the course DPS for each set of tees.
- That course DPS is then used to compare to all the courses the pros play to calculate the Dynamic Course Adjustment.
- The adjustment is dynamic because it will change as new data becomes available from each course.
Calculation for Adjusted DPS
- This calculation is done for each score
- Player DPS <PLUS> Course Adjustment <MINUS> Course DPS <EQUALS> Adjusted DPS
- GI will then use the best 40% of Adjusted DPS values and average them for the golfer’s Adjusted DPS value that will be used in the ranking
Player DPS: Here’s a specific example: Marty Zecheng won The Ascendant at TPC Colorado in 2022, a Korn Ferry event, with a DPS of over 118. TPC Colorado stretches to 7,995 yards. Marty shot 69, 67, 68, and 67. His DPS for the event was 118 ( (7,995x4) / (69 + 67 + 68 + 67) ).
Course Adjustment: TPC Colorado is a long course played at elevation and SIWGR’s Course Adjustment accounts for courses like this. The average DPS for TPC Colorado is 116, but the average Korn Ferry DPS is 106.
Course DPS: All scores for the Korn Ferry event played at TPC Colorado will be Course Adjusted by 10 to 106 (116 - 106).
Adjusted DPS: Marty’s DPS will be course adjusted down by 10 to 108 (instead of 118).
With DPS calculations and millions of rounds of scoring data, Golf Intelligence lets the data tell the story. The golf world is ready for an equitable and transparent ranking system. The SIWGR achieves those objectives.