Connect with us

Opinion & Analysis

The data behind Luke Donald’s decision to change instructors



Luke Donald recently made an instructor change to Texas-based swing coach Chuck Cook.

Back in 2011, Donald had an epic season. He finished first on the PGA Tour money list and the European Tour’s Order of Merit. He also became the No. 1-ranked golfer in the world. So the next obvious step for Donald was to win a major championship. But the fine play he exhibited in 2011 rarely resurfaced in 2012. He regained some of his old magic in 2013, but not enough to leave him satisfied.

So, what has happened to Donald’s game to make him switch instructors? First, let’s take a look at some basic scoring analysis, comparing his 2011 season versus his 2013 season.

Metric 1

The order of importance of these metrics when it comes to mathematically correlating to success on Tour is as follows:

  1. Par-4 Scoring Average
  2. Bogey Rate
  3. Par-5 Scoring Average
  4. Birdie Rate
  5. Par-3 Scoring Average

So, the major drop-offs were in metrics Nos. 2, 3 and 4.

Bogey Rate is the most important metric here. Having a low Bogey Rate is about two aspects of the game:

  • Being able to save par.
  • Being able to hit your approach shots close to the hole, where it greatly decreases the odds of making bogey.

The latter is what many golfers do not understand about why Bogey Rate is more important (from a mathematical standpoint) than Birdie Rate. The best way to avoid bogeys is to not put yourself in position to make them. Even the worst putters in the world are not going to make bogeys if they hit 16 or more greens per round and have an average birdie putt of less than 20 feet.

With that said, let’s take a look at Donald’s key performance metrics of 2011 versus 2013:

Metric 2

First, we should acknowledge that Luke’s 2011 season could very well never be replicated again. He ranked No. 1 on shots from 75 to 125 yards and shots from 125 to 175 yards. He also ranked first in Putts Gained. It is no small wonder why he played so brilliantly in 2011; if he had an approach shot from 175 yards or less he was by far the best player in the world. And if he was farther than 175 yards away from the hole, he was very good.

With that said, we start to see a noticeable difference in his play on the longer approach shots. When we examine it more closely we start to see a fairly large regression. Here are Donald’s rankings on long approach shots from the fairway/tee box in 2011 versus 2012.

Metric 3

This would explain the increase in Bogey Rate. Longer approach shots, particularly those from the Danger Zone, is where golfers tend to put themselves in position to make a bogey or a double bogey. Donald has seen a fairly large drop off on shots from 150 to 175 yards, but a massive drop off on shots from 200 to 225 yards.

Donald has never been very effective off the tee since he has been on Tour. In fact, his 2011 season (where he finished 132nd in Driving Effectiveness) was his best year with the driver on Tour. I believe that is what has held him back from winning a major, and why a course like Augusta National ends up fitting him the best out of all of the majors championship venues. It is very much an approach-shot-oriented course, and one where putting is extremely important. The other majors often require more precise and effective driving of the ball. The drawback is that Augusta also favors long hitters, which hurts Donald’s odds of winning a major there.

I would imagine that part of the change to a new instructor was that Donald hoped he could improve his tee play. At his club-head speed and distance off the tee, he needs to be able to hit about at least 68 percent of his fairways and get his Average Distance to the Edge of the Fairway to around 22 feet or less. Here is Donald’s data in these metrics during the past four years:

Metric 4

While Donald is not very far away from hitting 68 percent plus of his fairways and having an average Distance to the Edge of the Fairway of 22 feet or less, it goes to show that the slightest discrepancy can be the difference between being forecasted to win a major or two and having yet to win a major.

What I find interesting about Donald’s driving is in the radar data. Last year, there was a launch monitor report circulating on the web of Donald’s impact data. The launch monitor had Donald with a 2.5-degree downward attack angle with the driver. However, if you look at his radar metrics for this year on Tour there are some things that do not quite add up.

Metric 5

What we know about downward attack angles with the driver is that they result in golfers not hitting the ball as high or as far as they normally would with a “flat” attack angle or an upward attack angle. Furthermore, the downward attack angle will produce a higher spin rate.

What we see is that Donald’s distance ranking is noticeably worse than his ranking in clubhead speed. That is part of what we would logically assume given his downward attack angle. Furthermore, he has the 19th highest Spin Rate on Tour (2,922 RPMs). This is also in line with a golfer that hits the ball with a downward attack angle with the driver.

However, there are some contradictory metrics. His launch angle is fairly high (11.25 degrees), and he has the 41st highest ball flight on Tour. And as we know, higher clubhead speed players will generally hit the ball higher as well. Donald is a lower clubhead speed player who has a high ball flight. He is also doing it with a fairly high launch angle, but the spin rate is high.

I think the key piece to this is his ranking in Smash Factor (91st). And I believe what is happening for Donald is that he is hitting above the “sweet spot” on his driver. Tom Wishon has discussed how hitting above the “sweet spot” affects the ball’s flight with this diagram.

Wishon Diagram

Drivers are not designed to have a perfectly flat face. They have something called “vertical face roll,” which means that the face of the driver has a bulging design and the bulge runs horizontally (face bulged) and vertically (face roll).

With the larger 460cc drivers, this produces a club where if the golfer hits below the “sweet spot,” there is less loft. Conversely, if the golfer hits above the sweet spot, there is more loft. From there, the horizontal gear effect comes into play and if the golfer hits the ball above the sweet spot, that means the gear effect will reduce the spin on the ball.

Here are Donald’s radar metrics during the past four years.

Metric 7

Perhaps changes in equipment are a reason behind Donald’s unorthodox radar numbers given his 2.5-degree downward attack angle. But, his spin rate has lowered while his trajectory has gotten higher. And he still has an issue with getting his distance off the tee to match his club-head speed.

Donald will have his work cut out for him. But if he can get his long approach shot play back to his 2011 performance he will be very close to his old form. And if he can figure out his driving woes on top of it, he can be even better than he once was.

Your Reaction?
  • 0
  • LEGIT0
  • WOW1
  • LOL0
  • IDHT0
  • FLOP0
  • OB0
  • SHANK0

Richie Hunt is a statistician whose clients include PGA Tour players, their caddies and instructors in order to more accurately assess their games. He is also the author of the recently published e-book, 2018 Pro Golf Synopsis; the Moneyball Approach to the Game of Golf. He can be reached at [email protected] or on Twitter @Richie3Jack. GolfWRX Writer of the Month: March 2014 Purchase 2017 Pro Golf Synopsis E-book for $10



  1. MartyMouse

    Oct 12, 2013 at 8:02 am

    Enough about dynamic Loft!! Luke still has all the tools to get right back on top. Very interesting and well written! Thank you Richie!

  2. timmy

    Oct 11, 2013 at 5:57 pm

    whats the significance of distance to edge data?

    isn’t it possible, if not probable, that these pros intended to land the ball on certain spots of the fairway?

    middle of the fairway is not always the best spot for second shot

    • Richie Hunt

      Oct 14, 2013 at 3:08 pm

      Distance to the Edge of the fairway is based on shots that *miss* the fairway. The significance is it helps measure how large a player’s misses are.

  3. Andrew Cooper

    Oct 4, 2013 at 7:09 pm

    No disrespect, he’s a very decent player, but how he got to world no.1 beats me..

    • rdred

      Oct 10, 2013 at 7:07 am

      What part of it aren’t you understanding? This article has the stats right there, infront of your eyes…Did you read the article before typing your embarrassing comment?

      Best from the birdie zone.
      Best from the safe zone.
      Most Putts Gained.
      Best scoring average on par 4s

      What part of this are you struggling to understand?

      • Andrew Cooper

        Oct 13, 2013 at 8:33 am

        No argument Donald is a very good player-but he’s not a great player. He has strengths, but he also has big weaknesses (162nd in ball striking in 2013).

        The key stats are 251 PGA Tour starts, 5 wins, 0 Majors-a very nice career but not World no.1 material…

  4. Roger

    Oct 4, 2013 at 2:10 pm

    Really appreciate the analysis of the info!
    The huge drop in 150/175 and 200/225 accuracy is easy to see.
    Looks like the 2011 Irons are worth going back too……..

    I got into a negative impact around 2 degrees around xmas
    after being a +- Zero degrees hitter…took a while to fix!
    Keep up the Very Interesting Articles please!
    You know you can’t win over all the viewers in todays Instant Expert

    • naflack

      Oct 5, 2013 at 3:53 am

      passive aggressive and snarky, yes. subtle, no.

  5. FS

    Oct 3, 2013 at 11:23 am

    Very interesting!
    Did he also change balls during this same period? Has the change in the ball affected the numbers that much?
    The driver change obviously has affected it, for sure, but I wonder about the ball itself too. I wish there was some kind of machine that could tell us bit more about compression data of balls at impact besides just the Trackman smash factor data.
    How about the shaft? Did he change shaft when he changed the head?
    We all know that he also struggled with the change from the MP-62 to the 64.
    Obviously if his proximity to the hole suffers he has to work harder on the greens so the putting suffers and it shows.

    Nothing wrong with having a new set of eyes take a look at you. I hope he makes a good comeback next year.

    • Richie Hunt

      Oct 3, 2013 at 2:07 pm

      I don’t know if he changed golf balls or shaft, etc. That’s why I stated that perhaps the equipment causes his unorthodox radar numbers with the driver.

      Putts Gained is based on putts made percentage, BUT with relation to the field. And it’s where the golfer putts from. So not hitting your irons as well is technically separate from Putts Gained because it’s basing it on your ability to make putts from certain distances. If you’re leaving yourself with 20 foot putts instead of 10 foot putts, obviously…you’ll make less putts. But, that doesn’t matter in putts gained because it’s testing how well you can make those 20 foot putts (in this example) versus how well the field does from 20 feet.

  6. naflack

    Oct 3, 2013 at 8:43 am

    If you already know that…why are stating the hitting down creates backspin when you clearly know that it doesn’t?

    • naflack

      Oct 3, 2013 at 8:55 am

      Sorry but that makes no sense…
      I watched the maestro explain the entire thing.
      I’ll trust his explanation over yours, it’s makes more sense.
      Besides the fact that trackman data tells us that hitting down does not create spin by itself. Otherwise guys who hit down with their drivers would need less loft not more.
      I don’t understand with your knowledge how you draw such a conclusion that the player exhibited alone disputes?

      • Eric

        Oct 3, 2013 at 10:10 am,d.aWc

        If by “hitting down” you mean increasing downward angle of attach while also tilting the club face down by the same amount, you’re right, no change in spin rate. But if your angle of attack is increased downward while the clubfaces remains the same, result is higher spin rate.

        So, if Donald knows he should have a launch angle with a driver of about 11-12 degrees, and is changing the driver static loft to achieve it while using a -2.5 deg AoA, the spin will increase. He should do the opposite to increase distance…raise AoA, but use loft that continues to get about 11 degrees of launch angle.

        • naflack

          Oct 3, 2013 at 11:13 pm

          i wonder how many golfers understand the subtext involved, im guessing not many…

      • Richie Hunt

        Oct 3, 2013 at 10:34 am

        I can guarantee you that Trackman Maestro would agree with me that dynamic loft by itself (as well as attack angle) will not increase the spin rate. It’s the increase in the difference between AoA and dynamic loft, otherwise known as Spin Loft, that increases or decreases spin rate.

        • naflack

          Oct 3, 2013 at 11:08 pm

          im sure he would agree with the above premise…
          i dont however believe he would agree with the statement in the article that downward angle of attack increases spin rate.
          ive watched his videos, he states over and over again that the statement “hitting down increases spin” in and of itself is a myth. the distinction is important because the average golfer doesnt understand the difference between hitting down and spin loft. they see hitting down increases spin when unless they know how to do it properly it oly hurts their game.
          perhaps im the idiot and all the readers know the distinction, either way i felt the need to comment and appreciate your responses none the less.

          • Richie Hunt

            Oct 4, 2013 at 8:58 am

            I think we typically see golfers generating more spin when they hit down because their spin loft is *likely* to increase. They may bring their dynamic loft down with it, but generally not enough to keep the spin loft consistent (at least IMO).

            The real point of that portion of the article was to explore Donald’s struggles with the driver over his career. I don’t know his average dynamic loft, but I did know his average attack angle. What I found interesting was his launch angle would increase and he had very unorthodox numbers when we look at his club head speed, spin rate, max height, distance, etc.

            It could be an equipment thing, but it could be where he is hitting the ball. And I’ve worked with a couple of clients that changed how high they tee the ball up and that has affected their radar metrics and subsequently their driving off the tee.

            I usually try to tie these articles in with what the average amateur could possibly learn. There’s a popular myth that hitting above the sweet spot on the modern driver is a ‘hot spot’ on the driver. It’s actually not and I was trying to bring that to the attention of the reader and show a possible case of where this may be detrimental to a player like Luke Donald.

  7. naflack

    Oct 3, 2013 at 4:03 am

    downward angle of attack DOES NOT produce a higher spin rate, more dynamic loft produces a higher spin rate.
    the fact that he is as high as 19 in spin rate indicates that hitting down with the driver isnt increasing his spin rate.

    dont believe me…google “track man maestro” then watch him on youtube.

    • Richie Hunt

      Oct 3, 2013 at 7:59 am

      Sorry, but that’s incorrect. Dynamic loft by itself does NOT produce a higher spin rate. It’s about Spin Loft which is the difference between the Dynamic Loft and the Attack Angle. So all things being equal, if the attack angle gets steeper the spin loft increases and thus the spin rate increases. Conversely, all things being equal…if the dynamic loft increases the spin loft increases which means the spin will increase.

  8. td

    Oct 2, 2013 at 8:59 pm

    “The best way to avoid bogeys is to not put yourself in position to make them.”

    Haha…I swear this guy is Tim Mccarver’s prodigy.

  9. Lawrie Montague

    Oct 2, 2013 at 8:39 pm

    Rich thank you for sharing your analysis of Luke Donald’s current challenges with his game.

    With the wealth of statistical data available to us it is fortunate that we have people like yourself who can drill down into the data and present it in a way that makes sense.

    I wonder whether Luke Donald will be able to change his game enough to improve the numbers you suggest if he has to change some aspect of his golf swing.

    I imagine that someone as knowledgeable and experienced as Chuck Cook will guide him carefully, but as someone who works with tour players and elite amateurs helping them to improve their numbers in key areas of their game it’s indeed a slippery slope.

    Get it wrong and even great golfers are lost to the golf swing change wilderness, but get it right and Luke Donald might be able to bag himself a major or two.

    Only time will tell. Thanks again for an insightful article.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

On Spec

On Spec: The best gear of 2020 with guest Johnny Wunder



After a very interesting year in the golf equipment world, host Ryan Barath welcomes fellow GolfWRX writer and podcaster Johnny Wunder—of The Gear Dive—to chat about everything we saw in 2020 and what could be next.

Your Reaction?
  • 3
  • LEGIT0
  • WOW0
  • LOL0
  • IDHT0
  • FLOP0
  • OB0
  • SHANK1

Continue Reading

Flatstick Focus

Flatstick Focus: Interview with the Moose



In Episode 28, we chat with leftymoose, a very diverse putter collector from Canada. He has close to 50 putters from several manufacturers and helps shed some great insight into the collecting world.

Your Reaction?
  • 3
  • LEGIT0
  • WOW0
  • LOL0
  • IDHT0
  • FLOP0
  • OB0
  • SHANK0

Continue Reading

Opinion & Analysis

What makes a golf ball curve? (GolfWRX explains)



At some point, every golfer has asked the question “Why did that shot slice? Why did that shot hook? How did that shot go straight?”

The simple answer is physics, but the actual reason is a little bit more complicated and has to do with the relationship the golf ball has with the golf club as it approaches contact, but that’s why we’re here to explain why your golf ball travels where it does.

Zach Galifianakis Algorithm GIF by Product Hunt - Find & Share on GIPHY

It’s all about spin axis – AKA “sidespin”

Spin Axis – Trackman Golf

Side spin is the commonly used, but incorrect way to describe the spin axis of a golf ball as it travels through the air. Rather than try and define it myself, I will refer to the experts at Trackman to help me explain what’s really going on.

“Spin Axis is the tilt angle relative to the horizon of the golf ball’s resulting rotational axis immediately after separation from the club face (post impact).”

“The spin axis can be associated to the wings of an airplane. If the wings of an airplane are parallel to the ground, this would represent a zero spin axis and the plane would fly straight. If the wings were banked/tilted to the left (right wing higher than left wing), this would represent a negative spin axis and the plane would bank/curve to the left. And the opposite holds true if the wings are banked/tilted to the right.”

Unlike a plane in the example used by our friends at Trackman, a golf ball has no propulsion system, and all the force that causes it to move comes from the golf club. Depending on how the club makes contact with the ball will result in how the ball will fly. It’s no different than how a tennis or ping-pong ball travels through the air after it is struck with a racket or paddle – a golf club is just a “paddle” with a much longer handle length.

Why does a golfball curve right and left?

There are 2 main factors of the impact that influence how a golfball will curve;

  • The direction the clubface is aimed relative to the target line at impact
    Face Angle

  • The direction the club is moving at the moment of impact
    Club Path

Face-to-path – How to hit a draw

So now that we have a better understanding of why the golf ball curves in one direction or the other, the video below from TrackMan and Martin Chuck does a great job explaining the relationship of face to path, and how to hit a draw.

How to hit a straight golf shot

Being able to hit a straight shot is one of the most difficult things to do in the game of golf. The reason professionals don’t intentionally hit straight shots very often is that when it’s not executed properly it can create a shot that misses both right and left and if there is one thing professionals and low handicap players like to see is a golf ball that misses in one direction.

Face Strike Point

Beyond the relationship between the clubface and path, hollow golf clubs also have another factor at play, and that is the bulge and roll – curvature of the face from top to bottom and side to side. This curvature combined with the gear effect of hitting a shot outside the sweet spot results in the club imparting a higher measured spin axis and as a result the ball curves even more.

Check out this video below by TXG demonstrating how strike location on a driver has an effect on how the golf ball curves.

Your Reaction?
  • 71
  • LEGIT10
  • WOW3
  • LOL1
  • IDHT1
  • FLOP1
  • OB1
  • SHANK11

Continue Reading