The D-Plane Thread

[Carland]

I had been starting my drives either straight or with a little pull and then they would fade right. Using the "new" ball flight laws, I made a conscious effort to swing more from the inside on my downswing and I started to hit draws and drove the ball longer than I usually do on my home course. I tend to hit my irons straight or with a draw. When I tried the same "fix" with my irons, the ball started down the target line and then hooked badly. So I applied the ball flight laws when teeing off and ignored them when I hit irons. Overall, I hit the ball pretty well.

I think the problem is that I don't understand the "D-plane." The "new" ball flight laws can be summed up pretty simply: "The ball mostly starts on the angle of the clubface and curves away from the direction of the club path." But I can't figure out a quick way to sum up the D-plane. I know the D-plane articles say to swing the driver to the right of the target line for a straight shot and the irons to the left of the target line for a straight shot. But I don't understand John Graham's videos explaining the concept. Thanks.

[Carland]

Is there a simple one or two sentence summary of the D-plane?

[Carland]

Here is one summary that I found (AA means angle of attack and HSP means horizontal swing plane as in "does the swing plane angle to the right/positive or to the left/negative at impact):

A rule of thumb calculation [for hitting a straight shot]: When hitting down with a negative AA (iron shots or shots on the ground) you need to shift the HSP to the left by approximately ½ the amount of the AA. When hitting up with a positive AA (tee shots) you need to shift the HSP to the right by approximately the same amount as the AA.

http://www.planetruthgolf.com/Forums...c/Default.aspx

So, for a straight shot, it sounds like with irons the club path should start a little left of target because you hit down on the ball with an iron. With a driver, the club path should start a little right of the target because you hit up on the ball that is teed up. Is this correct?

[iacas]

I think the problem is that I don't understand the "D-plane." The "new" ball flight laws can be summed up pretty simply: "The ball mostly starts on the angle of the clubface and curves away from the direction of the club path." But I can't figure out a quick way to sum up the D-plane. I know the D-plane articles say to swing the driver to the right of the target line for a straight shot and the irons to the left of the target line for a straight shot. But I don't understand John Graham's videos explaining the concept. Thanks.

Very very few people hit a "straight shot." Almost no PGA Tour players do. If your ball has any curve on it at all the ball will ALWAYS be working away from the target if you plan for a straight shot... it doesn't make sense.

What you said is right - you need to swing the club to the left if the club is still going down to "zero out" the plane. With the driver IF you hit up on the ball, swinging out to the right more will help to "zero out" the plane. Odds are you had an over-the-top move a bit with your driver that you didn't have with the shorter clubs (that weren't teed up and as far forward in your stance). So do what you now do with the driver and keep hitting your irons the way you were. The D Plane is the more accurate way to describe the new ball flight laws, but frankly I don't find it terribly useful. To put it another way, the D Plane is three dimensional, while the basic ball flight laws are two dimensional. Kind of... Anyway, I understand the D Plane. In fact, I understand it really well. But will I ever use it in teaching someone? Will I ever use it in diagnosing my own swing? No, not really. I could go on and talk more about what the D Plane is and so on, but I don't think it's important enough to do so. Diagnose your ball flight using the basic ball flight laws. Diagnose things like "are my divots too steep" or "is my driver attack angle appropriate" as you would normally. I think D Plane is useful knowledge to have, but one that you almost never directly apply. P.S. A lot of people misunderstand the D Plane, too. I can have a steep divot, for example, implying a high negative angle of attack (say, -10 degrees would be REALLY high), but still be swinging straight down the line, which will produce a ball that has no sidespin).

[Stretch]

This is something I am currently trying to get to grips with more thoroughly. Thought it might be useful to have a dedicated thread to discuss the D-Plane in general, share instructional material and to raise any questions people might have about its application to our own games.

So far, this is the best quick primer on the subject that I have been able to find. Enjoy.

[iacas]

The D-Plane is relatively simple.

You could describe it as "the ball flight laws in 3D." Or if "the ball flight laws" are 2D (horizontal plane only), then the D-Plane is simply adding in the vertical plane.

Here's another way of looking at it: relative to your base plane line, if you're hitting down the club is also traveling out. If you're hitting up, the club is traveling in.

The closer together the "club path" vector (the path of the club at impact) and the "club face normal" vector (where the face is pointed at impact), the higher the "compression" because the lower the "spin loft." You can get too high a spin loft for a particular club and too low a spin loft for a particular club to work effectively.

The ball starts on the plane 85% or so towards the club face normal and curves UP THE PLANE. Again, just "ball flight laws in 3D."

James and I filmed a video awhile back but Dave hasn't published it yet. Hoping he does so soon... It may or may not poke a little fun at the fact that there are some 40-minute videos out there...

Update: I liked the video above a lot. I think he said everything the average (geeky) golfer needs to know after about 4:00, of course (I'm only 4:25 in though, heh). Also, I've been hesitant to talk about D-Plane because, well, the "ball flight laws" are about all you really need to know when playing golf. We don't fix anyone's slice by telling them to "hit down more" and the ball flight alone will tell you what the person is doing. The base plane is still vastly more important for most amateurs - too many get the base plane well left so even if they're hitting down and thus out, they're still swinging well left of the target line, and so slicing the ball. This is why, though, it's easier to slice a driver than the irons.

[LankyLefty]

Id agree that while I found this quite interesting Im not sure Id ever be good enough to consciously use it.

As he said it is hard to see on video and probably even harder to see in person. Its all very interesting but, I think from an amateur perspective its a lot easier and more productive to work on swing plane that is in line with the target line. I see this as food for thought but not something I could ever learn to use on a gold course.

[Zeph]

How can you not use it? Everytime you set up to hit a shot, you imagine the ball flight. You don't aim your body randomly and just let the clubface aim wherever it want. You aim body and clubface based on experience from hitting a lot of balls. Slicers will tend to aim more left, hookers will aim more right. You may not think about it in details like mentioned in this thread, but you are definitely using the ball flight laws.

D-plane, or the ball flight laws, is simply a way to explain why the ball goes straight, left to right or right to left. It's pretty easy theory too I would say, and it's very useful to know.

[Stretch]

The idea of the "base of the plane" (as opposed to just the "target line") has been the most thought provoking for me. The concepts may be relatively straightforward, but I still find it a challenge to really integrate them into my simple-minded frame of reference.

[CalBoomer]

Great video. As a physics geek, I loved it. Most clear demonstration of these principles I've ever seen.Until I figured this out for myself, I could never hit both irons and driver well at the same time. It was always one or the other. Anyone who questions how to position the ball in their stance for driving (hitting slightly up) vs irons (hitting slightly down), should be made to watch this video until they get it.

[jshots]

Yeah well it is quite simple but it is definitely eye opening, I'd never even considered such things. Assuming you swing each club exactly the same, then to hit a straight shot you should be aiming slightly off of center depending on whether or not the ball is forward or back in your stance.

Well also that is assuming that your club face is square at the bottom of your arc.

Interestingly if you aim straight at the hole and square your club face to the hole even though you move the ball forward or backward in the stance, the spin you put on the ball should tend to bring the ball back to the target line even though it will start either left or right of it.

[glock35ipsc]

At 40 minutes, this one by Brian Manzella is really long winded, but still a good one to watch.

[Zeph]

I don't understand how Manzella is able to use 40 minutes to explain D-plane. It's simple and you don't need that long to explain it.

[iacas]

Shot this in March. Finally edited out the one part Dave didn't like so we could publish it... ;-)

[sk golf]

Found a great video on D plane, so I thought I would share.

[Kobey]

Thanks a lot, now I'm having Fantasy Island flashbacks.