Analysis of Tiger’s past performances coming off long layoffs

Barring an eleventh-hour withdrawal, this week will bring the long-awaited return of Tiger Woods to competitive golf. Given the length of his current layoff, and the uncertainty surrounding the state of his game, it is hard to make any confident predictions about how Tiger may fare this week. However, we do believe that some insight can be gained by examining Tiger’s past performance in tournaments that followed competitive breaks.

In this article, we look at Tiger’s performance in all his previous returns from extended time away from the game. This includes Tiger’s opening tournaments each season, as well as the tournaments that followed breaks due to injuries or personal issues. In thinking about how Tiger performs coming off long layoffs, dominant performances at Torrey Pines and, to a lesser degree, at the season-opening Tournament of Champions, certainly come to mind. However, in recent years, Tiger’s return performances have been less than stellar, as, for example, in his 2014 and 2015 season debuts. Rather than getting swayed by these particularly memorable events, we take a closer look at the data to understand the overall story behind Tiger’s return performances.

To start, the graph below presents Tiger’s finish position in all tournaments that were played following at least two months of no competition, or were his season opening event. This graph, along with all the graphs in this article, are interactive; by hovering the mouse over a data point, you are provided with additional information.

Clearly, Tiger performed very well in his return tournaments before 2010, winning 7 of 15 starts with only a single finish outside the top 10. Keep in mind, however, that 8 of these starts came at the winners-only Tournament of Champions, which typically fields around 30 competitors. Conversely, after 2010 his performance was quite poor, missing the cut more often than he finished inside the top 10. As most observers of golf would agree, pre-2010 Tiger and post-2010 Tiger are quite different players, which makes this precipitous drop in performance not overly surprising.

Given this graph, one could make the claim that Tiger was great in his comeback events before 2010, but performed quite poorly in them afterwards. However, this could be very misleading. Before 2010, Tiger’s level of play was very high in general, so the performances documented above may not have been any better than usual. After 2010, an analogous argument could be made, given that his level of play was quite poor, in general (with 2012-2013 being an exception). Therefore, it should be clear that to understand whether or not Tiger performs well in comeback events, relative to his usual standard of play, we need to look at some measure of his baseline level of play for a point of comparison.

To get at this, we first calculate Tiger’s relative-to-the-field strokes gained (“relative SG”), which is just the field average score minus Tiger’s score, for all rounds that were not return events (i.e. all rounds in his career not included in the graph above). We calculate Tiger’s average relative SG for each year, and also calculate a 3-year moving average of his relative SG. For example, to get the 3-year moving average for the year 2000, we average Tiger’s relative SG in all rounds from 1999-2001. This 3-year moving average will be the baseline that we compare Tiger’s comeback performances to. In the following graph we plot Tiger’s annual average relative SG, as well as the 3-year moving average from 1997-2015.

Finally, for each return event, we plot the difference between Tiger’s average relative SG for that week and his baseline relative SG (we call this “personal SG”). For example, at the 2008 Buick Invitational, Tiger beat the field by an average of 5.88 strokes per round. The 3-year moving average of his relative SG for 2007-2009 was 3.15. Therefore, Tiger’s average personal SG for this week is (5.88-3.15)=2.73 strokes. In words, given Tiger’s typical level of play during this time period, he played 2.73 strokes better per round than expected at the 2008 Buick Invitational.

Now, our conclusions have changed. Both before and after 2010 Tiger performed worse, on average, in his opening events relative to his typical level of play at the time. However, pre-2010 this average was close to zero (-0.12), while post-2010 it was almost a full stroke difference (-0.82).

We can conclude that throughout his career Tiger typically played at slightly below his baseline performance level when coming off extended layoffs from competitive golf. So, while we would be comfortable making the prediction that Tiger will play slightly below his baseline level this week, this still doesn’t help much in predicting his actual performance. The problem is that we have no idea where Tiger’s game is at, and consequently we don’t know what a reasonable baseline playing level is at the moment. Therefore, like you, we are left wondering which version of Tiger will show up this week.