What is D-Plane? (Hint: We're not on Fantasy Island)

Have you heard the term D-Plane yet? If you haven't, and you are any kind of golf junkie, you will hear it soon.

If you are old enough to get the Fantasy Island reference ("Dee plane, Dee plane!!!") then you also probably learned to play golf before launch monitors, K-Vests, Trackman, and maybe even video cameras. The introduction of technology to golf instruction has sparked a revolution in our understanding of how the golfer, the golf club, and the golf ball interact to create that elusive perfect shot -- or create the banana ball, duck hook, push-slice, worm burner, etc.

The term D-Plane refers to a physics-based model of the collision between the golf club and the golf ball, the part of the swing we commonly call the impact zone.

The D-Plane is tricky even for golf teachers to conceptualize, primarily because it is a 3-D model. Yes, 3-D, just like Avatar or Toy Story 3. Contrast this with the old ball flight laws (see Fig. 1), which are a simple 2-dimensional representation. The D-Plane model enhances (some would argue contradicts) the old ball flight laws.

Fig.1 -- Old Ball Flight Laws in 2 Dimensions

The new 3-D model is mathematically derived and based on the laws of physics. First mentioned in Theodore Jorgensen's 1994 book "The Physics of Golf", D-Plane is short for Descriptive Plane. Jorgensen used the D-Plane to explain how the golf club imparts velocity, trajectory and spin to the golf ball.

D-Plane discussions heated up following the advent of launch monitors like Trackman and Flightscope. The doppler radar based launch monitors are able to measure club path, face angle, launch angle and spin rate at impact. And data generated by the launch monitors proved the accuracy of the D-Plane model. Thus we learned that our old 2-dimensional ball flight laws have some deficiencies.

D-Plane discussions can get complicated and mathematical enough to satisfy almost anyone's inner engineer geek. In simplest terms the golf club moves in a circle like a Ferris Wheel that is lined up at the target. But in the golf swing, the Ferris wheel is tilted at about 70 degrees, just like the swing plane. This 70 degree tilt means that the club head is only moving directly at the target at one point along the club path. It is this fact that makes the D-Plane different from the 2-dimensional models.

Fig. 2 -- D-Plane at Augusta from brianmanzella.com

Basically, what we have learned is that the ball's launch direction is based approximately 85% on face angle and 15% on club path (see Fig. 2).

This post is not meant to fully explain D-Plane, but rather to provide an introduction and stimulate curiosity. Try the blogs on John Graham's website to deepen your understanding of the D-Plane, and branch out from there. D-Plane Golf is another useful website. The internet and is loaded with examples of visual explanations of the D-Plane, as is Youtube. You can explore the concept as deeply as you would like.

Strangely enough, I find that the 2-dimensional ball flight laws correspond pretty well with what a golfer "feels" during his or her swing.

How We Started A Successful Ladies 9-Hole Program

Like so many golf courses around the country, our club in CT was faced with a dwindling ladies golf program. After talking with fellow professionals and whiling away this so-called New England winter on various internet golf forums, it's clear that we are not alone.

The PGA of America is banking on Golf 2.0 to help rebuild declining participation in our sport, ladies' statewide golf organizations such as the CWGA (CT Women's Golf Association) are forced to consider merging with neighboring associations, and some clubs have gone from weekly ladies' days to monthly ladies' days. Meanwhile, the United States and Europe are grinding through a serious economic recession, and for golfers that means less money to spend on the sport.

Yet last year we managed to increase our Tuesday morning ladies participation dramatically, as much as tripling attendance some weeks. We did this by offering a new ladies 9-hole league, a.k.a. the "Niners". The Niners have about as much in common with a traditional 18-hole group as a hybrid does with a one-iron.

Like a hybrid, The Niners group is user friendly in all the ways these ladies have told us they wanted.

1. No Tournaments -- While the 18-hole groups wants a tournament every week, most Niners do not want their score broadcast on a scoreboard at lunch. We do not organize a tournament for this group.

2. Play With Your Friends -- Niners make their own pairings by signing up on a sheet in the locker room. They are just learning the sport, so they choose to make their own groups. The ladies are able to play with women they are comfortable with while they learn more about the game. Of course, we also pair singles up with others who we think they would enjoy meeting and playing with.

3. Choose Your Own Tee Time -- So many of our Niner women are ferrying kids to school or camp in the mornings, so the 8:30 a.m. shotgun does not work for them. Tee times start at 9:45 am and run until around 11:00, and the ladies select their time by signing up first come first served in the locker room. If our golf course catered to more women with traditional work schedules we would tee the Niners off after work instead.

4. Play 3, 6 or 9 Holes . . . or 4 or 5 or however many holes you would like. Some of these lady golfers are fresh out of our beginner program (more on that in another blog), and 3 holes is plenty of golf. No pressure is applied to finish or keep score for a predetermined number of holes.

5. Protected Space on the Course -- The Niners are new to the game, and it takes a while to play golf when you are just learning. The ladies who sign up for this group are not required to play in 2 hours or less on the day they are playing with the Niners. To help speed up play, most of the groups are twosomes. Golfers who tee off behind them are made aware that the first nine holes might be a little slow. For the most part, the other members (men) are learning to respect the ladies group, reasoning that if their wives enjoy golf there is a much better chance that a membership at a golf club will remain a family priority. And more members leads to a financially stronger golf club.

6. Evening Golf -- One of our best attended events last season was a Nine & Wine Evening. The ladies teed off at 4:30 p.m. The event included wine before, during and after golf. What it did not include was any sort of tournament format. Niners and traditional 18-holers played together. Once again the ladies were able to make their own pairings if desired. Although some of the veterans would have preferred a tournament format, most were pleased that the entry fee went entirely to wine and hors d'oeuvres. We are considering adding to our evening ladies golf schedule in order to accommodate those ladies whose jobs interfere with morning golf.

The main thing our pros learned from this season is that beginner and even intermediate lady golfers want to play golf in a non-competitive, non-threatening arena. They want to enjoy nature, sunshine and good company while they learn the game.

If you think about it, this makes sense. Let's say the ski patrol put your time up on the scoreboard after every run you take down the mountain, or imagine the whole neighborhood knew that Stephanie across the street can make it around the local jogging loop a full 2 minutes faster than you. How much would you enjoy heading up for a ski weekend or going for that morning jog?

Golf is not dead. It is not dying. We can adapt and learn to offer our customers what they want in 2012. We look forward to growing our Niners group and will continue to change in ways that will better serve our customers. And as our ladies' needs and aspirations change, each year a few will graduate to 18 holes and eventually interclub and tournament play.