The problems with Rory and traditional golf statistics
Mark Twain was once said “There are lies, damned lies and statistics.”
This is often a popular adage from critics of an advanced metrics point of view. Normally this tends to occur with people who utilize anecdotal evidence to formulate their opinions and when the numbers tell them something they don’t like. The reality is that statistics do not lie, but incomplete and flawed statistics can lead to faulty analysis and conclusions derived from that analysis.
A prime example of this right now is the “fall” of Rory McIlroy’s play. People are stating that his dip in his performance is due to switching equipment. Johnny Miller thinks it is a giant mistake for Rory to switch his irons, as he did the same thing in his prime and he could never quite adjust to the change. Let’s take a look at his “traditional” golf metrics:
As we can see, Rory is better this year in fairway percentage and greens in regulation. He has regressed in scrambling percentage. Most people, including statisticians, would agree that greens in regulation has a larger impact on Tour success than scramble percentage. So, why has Rory performed worse this year despite hitting more fairways and greens in regulation?
Let’s take a look at his putting. While putts gained is not a “traditional” metric, it’s becoming more accepted as a traditional metric. Is the putting the problem?
The table shows that Rory is actually putting better this year than he did last year. It’s traditional metrics like GIR percentage, total driving and scramble percentage that tend to confuse golfers and consequently brush off metrics as “lies, damned lies and statistics.”
However, all it takes is to dig a little deeper and to use more detailed statistics and we start to see a better depiction of Rory’s play in 2012. Here’s a look at my main ballstriking metrics which include:
Driving effectiveness: A proprietary formula that uses the metrics of driving distance, fairway percentage, percentage of fairway bunkers hit, distance from the edge of the fairway and “missed fairways – other” to determine a player’s effectiveness off the tee.
Birdie zone: Proximity to the cup on approach shots from 75-125 yards.
Safe zone: Proximity to the cup on approach shots from 125-175 yards.
Danger zone: Proximity to the cup on approach shots from 175-225 yards.
These numbers suggest that the new equipment is not an issue or at least the new irons have worked out better for him this year.
While he is less effective off the tee, considering this is based out of 190 players on Tour he is still a driving the ball great.
So, where is the issue?
From what I have gathered so far, I would look at the two largest statistical regressions: scrambling and driving.
First, let’s look at my metric called “short game play.” This is the average proximity to the cup on all shots that are no more than 20 yards away from the edge of the green. We have seen that Rory has improved his putts gained, so let’s see if his actual skills around the green have regressed.
So yes, there has been a regression. But we simply cannot stop there because it is not a big enough regression to explain Rory’s dip in play from last year as we the numbers tell us that short game play does not have that large of an influence on a player’s score. Let’s drill down further and look at the attempts per round on shots from around the green.
And here is where we start to see some of the issue with Rory’s play. While he has regressed a bit in his ability to get the ball closer to the cup on shots around the green, one major issue is that he is leaving himself with more shots from a longer distance. With that said, that still does not quite tell the entire story. So, let’s drill down and examine his driving a bit further.
We know that he’s hitting it about the same distance off the tee. We also know that he is hitting more fairways this year. Since he is less effective off the tee this year, that leaves it to examining what I call the precision metrics of driving as we have already examined the power (distance) and accuracy (fairway percentage) metrics of driving.
And here is where we are starting to see more of the entire story into the regression of Rory’s play from 2012. Essentially, Rory is hitting his irons better and putting better. He’s hitting the ball virtually the same distance off the tee and is actually more accurate (fairway percentage), but he is much more imprecise off the tee this year and it is affecting his play despite the fact that he’s been better at the popular “traditional metric” greens in regulation percentage.
This is why I generally avoid examining greens in regulation percentage, particularly on the Tour level. For starters, it is too vague of a metric to really learn from. I have seen plenty of high GIR percentage players who struggle off the tee, but hit it great with their irons (Tiger). Conversely, I have seen high GIR percentage players who hit it great off the tee but have their struggles with the irons (Bubba Watson). It simply fails to tell the golfer how they get the ball on the green in regulation, either from a good drive or a good iron shot or both.
Secondly, across the board the numbers show that proximity to the cup has a higher correlation to success on Tour than GIR percentage. In fact, if you go to a Tour event it is obvious that Tour players have some sense of this as they are more apt to fire at a flag, even with trouble nearby, rather than to aim for the middle of the green. Simply put, the average Tour player makes one birdie putt outside 25 feet per 98 holes of golf!
Thus, Tour players instinctively understand that in order to make birdies on the course they need to get the birdie putt close to the hole. And most of the time the Tour players would take a 25-foot chip shot from off the green than the 50-foot putt that is on the green. And if you’re a golfer, you should probably do the same as well or start improving your short game enough so you start to want to have those much shorter chip shots over those longer putts.
What greens in regulation percentage does not tell us about Rory’s game is that he is hitting a higher percentage of greens in spite of being more imprecise with the driver. And what is happening is that when he misses a green it is coming more from a bad tee shot than a bad iron shot. Not only does that possibly mean that he is finding hazards and out of bounds more often (missed fairway –- other), but his bad drives are much worse this year and it leaves him with much more difficult shots to save par from.
So for now, I would say that the new irons and putter are actually helping Rory. But he now has to figure out how to get back his precision off the tee with the new driver. If he can, he’ll be even tougher to beat.