Percentage Error and Managing Expectations in Golf

[GolfSpy MPR]

Golf is hard and Tour highlights don’t give a realistic idea just how hard it is. Consider putting: right around 8’ is typically the break point on the PGA Tour for making 50% of putts. But even then, the very best putters on Tour are averaging just over 80’ of made putts per round. The bottom of the Tour is closer to 65’. Some quick math suggests, then, that the average made putt on Tour is between 3.5 and 4.5’. And yet how many of us start acting as though we’ve been forced to contend with a cosmic injustice when we miss a few six footers in a round?

What I want to do is use data to help myself objectively manage my expectations on the course. It’s one thing to realize that I can’t reasonably expect to stick every approach shot next to the stick. But what is reasonable for approach shots? When the frustration starts to rise, what measurable criteria can I use to talk to myself instead of listening to myself?

Like a lot of golfers, I first encountered the idea of “percent error” in a golf shot from short game coach Dave Pelz’s Short Game Bible. In his book, he talks about following Tour players on the course and manually charting their shots relative to their targets. The simple idea of percent error is to take the distance by which the shot missed the intended target and divide it by the shot length.

As a simple example, a 150-yard shot that finishes 45 feet (15 yards) from the hole is a 10 percent error shot. What Pelz argues in his book is that short game shots have a higher percent error and so that improvement on the short game should produce more immediate results in improved scoring. That isn’t my focus here.

Rather, I want to consider percent error as a way of managing expectations on the golf course.

For my part, I’ve found it fascinating to do Skills Assessments on my SkyTrak launch monitor. After each shot, the software not only tells you how far from the hole you were, but it turns that result into a handicap equivalent. I’ve been surprised at how “poor” a shot can be and still qualify as a scratch shot.

Thanks to ShotLink, the raw proximity data for Tour pros for various shots is already available. Consider this awesome chart from some of my favorite Twitter follows, Lou Stagner and Scott Fawcett:

What they've done here is broken down approach shots from the fairway in 5-yard increments. This chart already gives us some really eye-popping numbers. From 10 yards from the hole, on the fairway, Tour pros hit shots that finish within 3’ of the cup less than 50% of the time! I certainly would not have guessed that.

The downside of SkyTrak’s data and this chart for my purposes is that neither is easy to remember. When I laser the flag and find I’ve got a 150-yard shot, I’m unlikely going to remember that Tour average from this distance is a ball that finishes 25’ 3” from the hole.

What I hoped was to find a percent error number—hopefully, a nice round number—that I could keep in mind during a round to set expectations for a decent shot. So I took the Stanger/Fawcett data and calculated the percent error from each distance:

The first thing to note here is that, for Tour pros, their greatest relative accuracy is the 130–150 range, where most of them would be taking full swing PW. Outside that range, going closer and going further away, the percent error grows.

(It’s very important to note, though, that the absolute accuracy always increases as you get nearer the hole. Hitting a 130-yard shot to 22” feels better than hitting a 50-yard shot to 15”. In relative terms, the longer shot is more accurate. But on the green, one ball is still 7’ further away than the other, with a significantly smaller chance of being holed. In other words, don’t lay up to preferred distances.)

I’m hoping to keep updating this project. For my next move, I’m hoping to reach out to Arccos and Game Golf and Shot Scope, to see if they have any interested in sharing the average miss data at these distances by handicap. At this point, I’m inclined to think that a 10% error rule of thumb might be useful as a mid-handicap amateur, but I don’t have access to the data to prove that. Is that too much error compared to the Tour guys? Too little?

If anyone here knows if that information has been published and can point me to it, I’d be grateful.

[THEZIPR23]

19 minutes ago, GolfSpy MPR said:

Golf is hard and Tour highlights don’t give a realistic idea just how hard it is. Consider putting: right around 8’ is typically the break point on the PGA Tour for making 50% of putts. But even then, the very best putters on Tour are averaging just over 80’ of made putts per round. The bottom of the Tour is closer to 65’. Some quick math suggests, then, that the average made putt on Tour is between 3.5 and 4.5’. And yet how many of us start acting as though we’ve been forced to contend with a cosmic injustice when we miss a few six footers in a round?

What I want to do is use data to help myself objectively manage my expectations on the course. It’s one thing to realize that I can’t reasonably expect to stick every approach shot next to the stick. But what is reasonable for approach shots? When the frustration starts to rise, what measurable criteria can I use to talk to myself instead of listening to myself?

Like a lot of golfers, I first encountered the idea of “percent error” in a golf shot from short game coach Dave Pelz’s Short Game Bible. In his book, he talks about following Tour players on the course and manually charting their shots relative to their targets. The simple idea of percent error is to take the distance by which the shot missed the intended target and divide it by the shot length.

As a simple example, a 150-yard shot that finishes 45 feet (15 yards) from the hole is a 10 percent error shot. What Pelz argues in his book is that short game shots have a higher percent error and so that improvement on the short game should produce more immediate results in improved scoring. That isn’t my focus here.

Rather, I want to consider percent error as a way of managing expectations on the golf course.

For my part, I’ve found it fascinating to do Skills Assessments on my SkyTrak launch monitor. After each shot, the software not only tells you how far from the hole you were, but it turns that result into a handicap equivalent. I’ve been surprised at how “poor” a shot can be and still qualify as a scratch shot.

Thanks to ShotLink, the raw proximity data for Tour pros for various shots is already available. Consider this awesome chart from some of my favorite Twitter follows, Lou Stagner and Scott Fawcett:

What they've done here is broken down approach shots from the fairway in 5-yard increments. This chart already gives us some really eye-popping numbers. From 10 yards from the hole, on the fairway, Tour pros hit shots that finish within 3’ of the cup less than 50% of the time! I certainly would not have guessed that.

The downside of SkyTrak’s data and this chart for my purposes is that neither is easy to remember. When I laser the flag and find I’ve got a 150-yard shot, I’m unlikely going to remember that Tour average from this distance is a ball that finishes 25’ 3” from the hole.

What I hoped was to find a percent error number—hopefully, a nice round number—that I could keep in mind during a round to set expectations for a decent shot. So I took the Stanger/Fawcett data and calculated the percent error from each distance:

The first thing to note here is that, for Tour pros, their greatest relative accuracy is the 130–150 range, where most of them would be taking full swing PW. Outside that range, going closer and going further away, the percent error grows.

(It’s very important to note, though, that the absolute accuracy always increases as you get nearer the hole. Hitting a 130-yard shot to 22” feels better than hitting a 50-yard shot to 15”. In relative terms, the longer shot is more accurate. But on the green, one ball is still 7’ further away than the other, with a significantly smaller chance of being holed. In other words, don’t lay up to preferred distances.)

I’m hoping to keep updating this project. For my next move, I’m hoping to reach out to Arccos and Game Golf and Shot Scope, to see if they have any interested in sharing the average miss data at these distances by handicap. At this point, I’m inclined to think that a 10% error rule of thumb might be useful as a mid-handicap amateur, but I don’t have access to the data to prove that. Is that too much error compared to the Tour guys? Too little?

If anyone here knows if that information has been published and can point me to it, I’d be grateful.

Good Stuff!

Pelz percent rule only applies to shots being aimed at the hole. My guess is that would max out at around 50 yards or less. Anything over that and pin placement and course design start coming into play. A tour player may miss a 150 yard shot to 45 feet but in reality he may have missed it only 1 yard from where his target was. It is not a 10% error shot. 

Scott and Lou provide great information! What Lou has been putting out this year since he joined Decade is invaluable information to managing expectations. 

I have heard that if you use 18% x distance to hole you will get a real close guess at PGA tour proximity from almost all yardages. Looking at chart it is not exact but certainly close and easy to use on the course. 

[edingc]

6 minutes ago, THEZIPR23 said:

Scott and Lou provide great information! What Lou has been putting out this year since he joined Decade is invaluable information to managing expectations. 

Some of the best golf content in Twitter, in my opinion. 

Good stuff, MPR. I'll have to keep this thread in mind this summer. 

[bluesmandan76]

I’ve posted about this several times. A 10% margin of error gets you to scratch. Pelz says the pros average around 8%. And that’s really interesting how their margin gets lower and lower the shorter the shot is. I’ve only been using a static percentage as a standard to measure my game so maybe I should adjust my standard on shorter shots.

I’ve used this 10% rule as my means for examining my game for a while now. When I see any part of my game (whether it’s chipping, pitching, full approaches, or putting) start to trend upwards, I know I need to work on that part of my game. If I can keep it generally below 15% I’m fairly happy.


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[bluesmandan76]

One other comment on this, about managing expectations. When I started using percentage of miss to measure my success, I found that I had been getting upset about the wrong shots! Plenty of the shots I used to think were bad were actually pretty good, and a lot of the shots I thought were acceptable were quite bad! It really did change my expectations and goals.


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[cksurfdude]

On 1/27/2020 at 5:43 PM, THEZIPR23 said:

A tour player may miss a 150 yard shot to 45 feet but in reality he may have missed it only 1 yard from where his target was. It is not a 10% error shot. 

I think this is key -- what was _your_ proximity to _your_ target (on any and all shots)?
(me: I'm rarely going at pins; more often to the center of the green)

As a part of my post-shot routine, I try (!!) to objectively evaluate things like...
- Did I hit it solidly?
- Did I hit the kind of shot I'd intended?
- Did I get it within .. roughly .. 10-20% of my intended target?

The way I look at "scoring" my shots are...
- within 10% means you hit a 90% successful shot = an "A" grade
- within 20% means you hit an 80-something% successful shot = a respectable (and playable) "B" grade
- etc.

Then I try to evaluate what I did do well and what still needs more work (which a lot of times is related to focus and concentration).