If you have watched any golf TV broadcast in the last year in a conscious state then you know the PGA Tour has wrapped it’s arms around a new statistic for putting performance called Strokes Gained Putting. It has become the overnight standard for determining who is putting the best in any given Tour event.
The genius behind this concept is Mark Broadie professor and research maven at Columbia University and a single digit handicapper to boot. His background is in statistical analysis of financial performance dealing with unintelligible things like pricing of derivative securities, risk management, and qualitative decision-making under uncertainty. Sounds to me like a man who can get to the bottom of your putting woes.
Mark Broadie’s recent book “Every Shot Counts” is the professor’s exhaustive explanation of the Shots Gained statistical approach to performance in all aspects of the game of golf. With the help of the PGA Tour’s commitment since 2004 to collect exacting data on every shot and putt at PGA Tour events through their Shotlink system, Broadie has found the ocean of data to develop his theories and articulate how to explain much of what we see week-to-week on the tour.
He starts from an obvious premise that the benchmark statistics that have been used for years to measure golf performance, Fairways Hit, Greens In Regulation, Scrambling, Putts Per Round, and Putts Per Green In Regulation are too shallow to give any meaningful direction to the players on how to improve their performance vis-à-vis their peers.
From the stats he gleaned that PGA pros average 29 putts a round with an average score of 71. Tournament winners average 67.4 strokes per round so the differential between winning and the average is 3.7 strokes per round. Pertinent question is what part of their game contributes to the 3.7 strokes per round advantage of the winner over the field, their shots gained on the field.
To that end he says, “The final score on a hole typically results from the accumulation of fractional gains and losses on each stroke.” “The quality of a golf shot is measured by progress to the goal of getting the ball in the hole in the fewest possible strokes”. “Strokes gained [was developed] to measure a player’s shot outcome against a peer performance benchmark for the same shot.” “Strokes gained measures [a player’s] progress to the hole in terms of the average number of strokes to hole out.”
A similar conundrum has existed in baseball for a century. Broadie says, “In baseball batting average was long the main stat used to measure proficiency at the plate……the sabermetrics revolution in baseball stats….. show that another stat, the on-base plus slugging percentage is a better predictor of a batter’s contribution to runs scored.”
With the help of the Shotlink data available to him Broadie sketched out how strokes gained putting could prove a more accurate measure of putting performance for the professionals. The average strokes gained putting for all golfers in a PGA event gives the ponderous among us a simple and reliable measure of the players relative putting proficiency that week. If Luke Donald is 15 feet from the hole and makes the putt and the average number of putts a pro takes from 15 feet is 1.78 then Luke has .78 strokes gained putting for that effort. If Vijay is five feet from the hole, where the average pro takes 1.23 strokes to hole out, and two-putts then he has a -.23 strokes gained putting on this hole. The sum of the strokes gained putting for the 18 holes based on their first putt is the player’s strokes gained putting for the round.
Below is a Broadie chart that shows the top 50 putters on the PGA Tour from 2004 to 2012 using Strokes Gained Putting (SGP) as the measure of relative performance. Not surprising Luke and Tiger are in the top five but so are Aaron Baddeley and Greg Chalmers. Some surprise in the names not in the top 20.
Broadie has moved on to trying to convince the Tour on using a similar statistical method on evaluating tee shots, approach shots (over 100 yards), and short game shots. It measures how much a person gains on a shot he has played by measuring the decrease he has accomplished during this shot in the average number of strokes to hole out minus one to account for the shot played. Simply stated a shot that is better than Tour average will have positive strokes gained and a shot worse than average has negative strokes gained.
Using this method the strokes gained can be used to compare driving, approach shots, short game shots, and putting because the proficiency of all the shots are measured by a common unit of strokes gained.
After applying this to the Shotlink data Broadie concludes that for the top 40 golfers from 2004 to 2012, putting only contributes 15% to their scoring advantage over the field while driving contributes 28% to their scoring advantage.
He asserts that an extra 20 yards of driving distance, without regard to accuracy, is worth about .75 strokes gained per round. This extra distance gives them a shorter approach shot, with a lower average shots left to hole out, and that translates into strokes gained. So it is more important to drive it long on the Tour than hit fairways in terms of gaining strokes on the competition.
When it comes to hitting approach shots it is all about proximity to the flag to improve one’s strokes gained. This has been Tiger’s secret in dominating the game the last decade and a half. The closer Tiger’s shot from 175 yards out gets to the flag versus the average Tour player the more strokes gained he has on the field.
This chart shows Strokes Gained Approach (SGA) and you can see that Tiger’s SGA of 1.28 is .73 better than the average top 40 player. When Broadie breaks it down further you can see that on meat and potato approach shots from 100 to 150 yards and 150 to 200 yards Tiger is hitting it considerably closer to the hole than his peers and that is where he gains his shots on the field.
The only problem with all of this is that it relies on the inundated accurate data collection of every shot a pro plays in a tournament round. No such data collection vehicle exists for the average player to use or even for researchers to use to compile strokes gained benchmarks for the common golfer. This is a huge case of having the cart before the horse when it comes to helping you and me.
This review just scratches the surface of what Broadie reveals in this readable and informative treatise on this Shots Gained Method for analyzing golf stats. He dispels many of the myths and certitudes we have held dear for years about golf performance. You can pitch “Drive for show and putt for dough” right over the embankment along with a bunch of others.
Broadie devotes an entire chapter to the relative difficulty of uphill versus downhill putts, importance of break on putts, and what distances actually separate good putters from average putters. He even includes practice drills that can help you understand the strengths and weaknesses of your game around the greens and work on the things that will make a difference in gaining strokes on your buds.
He presents the book in a very readable format with lots of substantiating charts and graphs to help you comprehend what he has concluded. Like all good college text books he has reiterative summaries at the end of each chapter that make prepping for the exams much easier.
This is not a fast read but it is a worthwhile intellectual indulgence for the inebriated golf fan. The shelf in your golf library is yearning for this one.
Every Shot Counts
Mark Broadie (2014)