Tiger Woods’s Decline: What Does the Data Say?

On Sunday, as I was traveling to my son’s soccer game, I decided to turn on ESPN Radio. At that time of the day, the Beadle & Shelburne show was on. The hosts, Michelle Beadle and Ramona Shelburne, were discussing a recent article by Wright Thompson called “The Secret History of Tiger Woods” (http://espn.go.com/espn/feature/story/_/id/15278522/how-tiger-woods-life-unraveled-years-father-earl-woods-death). They discussed pieces of the article, but inevitably began speculating on the reasons for Tiger’s decline, jumping right to the juicy stuff—his sordid private life.

While listening, it occurred to me that I’ve been hearing about Tiger’s decline for a couple of years now and it is always followed by speculation on what led to his decline. Is it a psychological issue? Is it his multiple injuries? Or is it his out of control personal life? Perhaps, like the loss of Samson’s hair, the end of Tiger’s extramarital affairs caused him to lose his superhuman golfing abilities!!

I personally have a much simpler theory—Tiger’s old! Of course, Tiger is only 40, so he’s not really old (I’m only a few months younger than him and definitely don’t feel old yet), but in terms of professional athletes, he is definitely past his prime. But this is just my theory. As a data and analytics guy, I decided to see what the data says.

The Aging Curve
Any discussion about the age and performance of professional athletes should probably start with Bill James and his aging curve. Bill James was the original Nate Silver. He was a true baseball statistics geek who created the voluminous Baseball Abstract starting in 1977. He was also instrumental in the creation of "sabermetrics", which is a system of analysis of baseball and baseball players through use of statistics. The real Nate Silver, as well as numerous others, have applied sabermetric models to other areas—for Nate Silver, most notably politics.

Through his study of baseball statistics, James developed the idea of the baseball aging curve. An aging curve essentially shows the average performance improvement or decline that should be expected of a player as he/she ages. While James’s aging curve was focused on baseball, similar curves can be created for any sport.

Jake Nichols writes an interesting blog called “Golf Analytics” (https://golfanalytics.wordpress.com/) on which he applies a number of statistical methods to better understand the game of golf. A few years ago, he created an aging curve for PGA Tour golfers, as shown below.

As you can see from the curve, average player performance starts to decline around 30, with a steep decline staring around 37 or so. Considering that Tiger is now 40, is it difficult to believe that Tiger’s performance has fallen off over the past few years?

But Tiger’s Not Just Any Golfer
But you may be thinking “Tiger’s different! He’s not just any PGA Tour player”. Yes, this is true—Tiger Woods, without a doubt, is one of the best golfers who ever lived. This being the case, it is probably reasonable to think that his aging curve might be a bit different than the average. So, perhaps we should compare his performance to the best golfer of all time, Jack Nicklaus.

I obtained statistics on the total number of wins for both Tiger Woods and Jack Nicklaus, then used QlikView to quickly graph the data by age.

As you can see, Tiger peaked pretty early on, first winning 4 tournaments at the age of 21, followed by 8 wins at 23 and a whopping 9 wins at 24. He then slipped a bit in 2004, quickly recovering the following few years. At age 34 and 35—around the time of his cheating scandal—he failed to win any tournaments. He then recovered for a couple of years, but has not won a tournament since the age of 37.

Jack Nicklaus’s history looks a bit different than Tiger. He didn’t start winning until he was a few years older; and he was generally more consistent throughout his career. He peaked at 32 and 33, winning 7 tournaments both years. But, Like Tiger, he failed to win in his late 30’s—his last win came at the age of 38.

So, while the patterns are a bit different for the world’s two best golfers of all time, the trends are pretty similar. Their careers were strong in their early 20’s and, for the most part, remained so through most of their 30’s, before an eventual decline in their late 30’s. If we revisit the Jake Nichols’s aging chart, we will recall that the most significant declines in performance tend to happen around the age of 37. The declines of both Tiger Woods and Jack Nicklaus align with that quite nicely.

So what does the data say? While not a thorough analysis, I think it’s pretty clear that the largest factor in Tiger’s decline is his age. While he may have seemed superhuman during his prime, he is, in fact, human just like the rest of us and we can’t expect him to go on winning forever.

Ken Flerlage, April 28, 2016

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