It spins, it flies, it fades?

Note: you can find the complete collection of these posts at Notes from Bogeyland.

A flying disc is not a baseball: disc physics 1

(This is the beginning of an occasional series on the physics of disc golf, starting with a simple explanation of why you don’t need to throw the disc up high (usually). We may not get into all the details now, but we’ll do so later on.)

Knowledge of how and why a disc flies will not make you a better disc golfer: only practice and experimentation can do that. But understanding the physics of disc flight may provide geeky pleasure nevertheless.

My most common disc-throwing mistake

My early disc golf shots went sharply up, took a hard left, and landed about 50 feet away, like this:

That’s mainly because I threw it up at an angle to get it to fly to the target. That’s what you’d do with a baseball, but a disc is not a baseball. A disc is a wing. While both a baseball and a frisbee have spin, a frisbee generates far more lift compared to a baseball, so you don’t need to loft it high to get it to travel far.

What a baseball does

If you throw a baseball at a 45 degree angle it will go farther than if you throw it flat, parallel to the ground:

What a disc does

But if you do the same thing with a disc, you’ll get the opposite result. That’s because the disc generates lift better if it’s roughly parallel to the direction of travel. If it gets too nose-up, then it stalls (like an airplane wing can stall at too high an angle of attack). When the disc stalls, the interaction of the lift and the spin make it fade to the left (for a right-hand backhand throw). So you want to delay the stall as long as possible to get the farthest, straightest flight out of a particular disc.

This is what happens to me when I throw the disc too high (top view):

If you’re left-handed, you’re likely to see this for a backhand shot thrown too high:

The question I find myself asking is “Why do they do that?”

A flying disc is a simple wing with a twist: it spins. If you throw a disc without any spin, it will tumble and not fly very far. The spin adds stability. It also changes the way the disc flies compared to a non-spinning wing.

Disc golf discs are more like paper airplanes than like baseballs. If you throw them up sharply, they’ll stall, losing their lift, and start falling back to the ground. As they fall, the interaction between the lift and the spin makes them turn hard left (or hard right if you throw a left-handed backhand). Here’s a side view of a lofted disc’s flight path:

Avoiding excessive fade

If you want to throw a straighter shot, trust the disc to provide the lift -- you don’t need to loft it too high. And you definitely don’t want it to leave your hand with the nose pointed too far upwards. This is more like it:

The disc, acting as a wing, flies farther without stalling, and the spin stabilizes the disc as it flies. The disc may still fade to the left near the end of its flight, but it will go farther before it does so. Also, because it’s closer to the ground, it won’t fade as far to the left:

If you aim properly, you should get much closer to the target with a flat throw (top view):

Fade can be your friend

Sometimes however, a fade to the left or right is just what you want:

My shot on this hole often goes left too early (green arrow), probably because this is a downhill shot. I need to send the disc on more of a downhill path, otherwise it stalls out and fades hard to the left before it gets all the way down the hill.

Next time: what causes the late fade?

Commitment and Smoothness

 

Time to wrap up my MVP Open posts. Volunteering to work at this tournament was a great experience, and the best part was seeing top-quality disc golf in person. Two standouts:

Commitment

James Conrad is totally committed to his job. 

James did not win the MVP Open at Maple Hill this year, but he is one of the most committed players I’ve ever seen. His tee shots usually begin with long runups starting way behind the tee box and he seems to put every ounce of energy into his drives. I love the way his body winds up and then unwinds in a windmill of arms, legs, and hair, from which the disc usually emerges on a fast track toward the basket. 

Here is James throwing a long approach putt on the last hole of the final round at Maple Hill:

James Conrad’s next-to-last shot at the 2021 MVP Open at Maple Hill.

James is, of course, famous for his next-to-last shot in regulation at the 2021 PDGA World Championships (watch this for a few minutes to see James in action).

Smoothness 

Matthew Orum’s form is unorthodox but smooth! Watching any aspect of his game is fun, including drives, upshots, putts, and his sunglasses. Ben took this shot of Matty O preparing to throw at hole1 at Maple Hill:

Matthew Orum on the tee at hole 1 during the 2021 MVP Open at Maple Hill.

My new job: Spotting hole 17

 

Finding the discs

After the sometimes tedious work of setting up the course, I got to be a spotter on hole 17 on Friday, the first round of the MVP Open.

A spotter stands on the fairway to keep an eye on where the tee shots land. For the pros, we are a long way from the tee.

Some holes have boundaries marked by ropes or stone walls: discs that cross those boundaries are said to be out-of-bounds and the player must add a penalty stroke to their score. Spotters help by marking where they think the disc crossed from being in-bounds to being out-of-bounds, though the players (as a group) make the final call.

Here’s a map of hole 17. The Christmas tree field to the left of the initial fairway is out of bounds:

At Maple Hill, many of the fairways (like this one) are riddled with Christmas trees that sometimes like to eat discs. Spotters save time by finding discs in and under the trees and marking them before the players reach the fairway after teeing off.

View from the teepad of hole 17, where I spotted on Friday.

Hole 17, Maple Hill, Leicester, Massachusetts

This hole was deemed not hard enough for the pros last year, so they moved the tee pad about 60 feet farther back into the woods. Both the regular trees and the Christmas trees in the fairway are hazards here. I would be happy to make it through the initial gap here, but most of the pros ended up way up the hill on the right side of the sunny Christmas tree field.

Throwing straight: What I'm working on this weekend

 Originally posted on July 30, 2021

Going back to basics

After several months of playing disc golf regularly, I feel like I’m starting to get a feel for the discs, but I’m still frustrated that they don’t always go where I want them to. I’m taking some baby steps backward and starting to throw more putters and midrange discs, and practicing throwing them straight. So much of disc golf is based on feel, and you can't get the feel if you don’t practice.

I love playing rounds, and that has helped my game improve, but it can be frustrating to learn on the course, especially if you’re scoring!

I try to get to a field or a park where I can practice short, straight throws and short approach shots. I need to work on distance too, but I think that will take longer to develop. And putting, of course.

Drawing a line in the grass

Instead of spraying random shots in an open field, I decided to try to stick to the straight and narrow:

Here are my first baby steps: short, straight throws:

Drawing a line in the woods

I’m lucky to have a park nearby that has some trees, so I can torture myself (and my discs) a bit more realistically:

I’ve been trying to throw down this tunnel, and I’ve also played some object disc golf among these nearby trees:

We’ll see if it helps me improve over time.

What kind of practice do you find most useful?

My new job

Hard work, no pay

After being retired for nearly a year, I started a new job today. I'm on the volunteer staff for the MVP Open disc golf tournament at Maple Hill Disc Golf. This is a beautiful course and an amazing tournament. And it looks like we're going to get some nice weather when the tournament begins on Friday.

Today, a group of us started gussying up the course for the weekend with tents, banners, and fancy out-of-bounds walls. During the tournament, I'll be spotting discs on two different holes. It should be an interesting week.

A taste of Maple Hill

Here's my son Ben teeing off from the white tee on hole 1 earlier this month:

 Hole 1, white tee. Maple Hill Disc Golf, Leicester, Massachusetts.

The pros tee off from farther back and throw directly across both the Christmas tree field and the pond:

Map of Maple Hill, hole 1, Leicester, Massachusetts.

I would be lucky to make it to the near edge of the pond off the tee. But I saw a couple of pros practicing today make it well over the pond and into the Christmas trees (more than 475 feet!). It's astonishing to see shots like that in real life.

Disaster and triumph at Maple Hill

 July 12, 2021

I find myself in a familiar situation

I often find myself standing on a small wood and brick platform at the end of a narrow wood road. I am trying to decide which of a dozen or so flying discs to throw toward the target, a metal basket a few hundred feet away. I make my decision, take a few steps forward and fling the disc. In my mind’s eye, it soars smoothly down the path, curving around several trees before landing gently 20 feet from the basket. Instead, it hits a tree 20 feet away from the tee pad and drops to the ground.

This is often the reality of disc golf, an activity that is exploding in popularity during the pandemic. Disc golf combines the joy of hiking, the complex physics of spinning frisbees, and the frustration of golf into one addictive sport.

A sudden disaster on hole 6 derails my dreams of success

Here’s a case study from my most recent round during a flex tournament at the Maple Hill Disc Golf Course in Leicester, Massachusetts.

I started off well with two pars on holes 1 and 2. I followed this up with two double bogies on 3 and 4, then a single bogey on 5. So, +5 after 5, which is firmly in Bogeyland. Hole 6 is a fearsome par 3 that most people are happy to par (including the pros).

I threw a straight shot off the tee. Straight into a tree, landing barely over the out-of-bounds wall. From there, shooting 3 including a penalty shot, I aimed to get back to the fairway but faded heavily at the end and ended up in the OB pond on the left side. Shooting 5, I released early, hit another tree and bounced back into the pond. Shooting 7, I managed to lay up in the middle of the fairway. My first in-bounds shot on this hole -- Yay! After a decent upshot, I put it in the basket after 9 strokes, scoring +6 on Hole 6. This is the highest score I’ve ever had on a hole (though I probably took more strokes in some of my early outings). The following picture illustrates my travails on this hole:

My path to Hole 6 at Maple Hill. Original drawing credit: DGPT 2020 Maple Hill Caddie Book.

Ben exemplifies a better strategy (that actually works)

There’s a different way to play this hole. Here’s my son Ben after acing Hole 6 in January 2021. You can see the OB stone wall to the right and the basket way off in the distance (to the left of center with a flag). The pond lurks behind the pine trees to the left:

Hole 6 Blue at Maple Hill, Leicester, Massachusetts

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Ben threw that yellow Star Wraith dead straight with a right-hand forehand. It flew right down the middle of the lane. His friend Jack and I marveled: it looked like a great shot, sailing smooth and level, missing all the trees. About 25 feet before the basket, it hit the ground then skipped up and hit the chains. Ace!

Ben’s path to the basket is much simpler than mine:

Ben’s path to the basket on Hole 6 at Maple Hill.

No aces for me yet, and I certainly don’t expect to get my first on this hole!

How about you -- any aces yet?

Welcome to Bogeyland!

July 5, 2021

Frisbees, trees, and me

Disc golf, like its older cousin golf (or ball golf, as disc golfers refer to it) is a humbling sport. It is simple in concept: get a flying disc from a designated tee location to a metal basket located some distance away using the fewest throws. In practice, things get in the way. Mainly trees.

As a novice disc golfer, I am well acquainted with the trees of New England. There are many of them, and they like discs!

Hole 16 at Clement Farm disc golf course, Haverhill, Massachusetts.

I started disc golfing in earnest in December of last year. My first scored round that I can recall came in at 36 over par for 18 holes, meaning that I averaged two strokes over the designated number of strokes allocated to each hole for a par score (known as a double bogey). I played a few rounds before doing any scoring, and I recall throwing way more than double bogey on most holes, so I probably came in at something like 45 over par.

The great thing about being a beginner is that it’s OK to suck. And you tend to improve fast. In the six months since I started playing and scoring, I’ve improved from +36 to a high (or low) of +13 for an 18-hole round. Of course, some disc golf courses are more difficult than others, so it’s hard to compare scores. But in general, I’ve improved from double-bogey to single-bogey (+18) range. So that’s why I’m calling this blog/newsletter Notes from Bogeyland. I expect to be here for a while.

Hole 16 basket (in the middle of the photo) at The Hill, Devens, Massachusetts.

But disc golf is a sport for optimism and high hopes. So while I call this Notes from Bogeyland, I am trying every round to escape from Bogeyland and enter Half-Bogeyland someday. It’s hard to contemplate anything beyond that right now.

I have occasional glimpses of the lands beyond Bogeyland, but they are fleeting. I get the occasional par (which feels like a birdie to me). And once in a great while, I get a birdie. According to my UDisc stats, I have played 1149 holes, and gotten only 16 birdies (1.4%). I’ve gotten 263 pars (23%), 408 bogies (36%), and 264 double bogey or worse (also 23%). So the stats point the way to improvement: shoot more birdies and pars.

If only it were that easy.

Tune in here for more non-expert disc golf musings.