Friday, November 6, 2009
Answers To Your D-Plane Questions: Part IV
After giving a synopsis of D-Plane and Trackman numbers, I'll go into some of the questions I've received.
1. What exactly is 'swinging left?'
All the golfer does is move the plane line to the left of the target. If the golfer wants to hit it dead straight with an iron, they should aim the clubface at the target and move the plane line slightly to the left depending on their angle of attack. For instance, if a golfer were to get on a plane board (pic below), the plane line is at the base of the plane board. The golfer should swing along the plane board. Using D-Plane to hit it straight, the golfer would want to aim the face at the target and aim the plane board slightly left of the target. It's almost the setup to hit a fade according to the old ball flight laws.
2. What's the difference between swinging left and coming over the top and aiming left?
The over the top move is when the golfer gets above the plane. They 'bend' the plane line instead of staying on the plane. The reason there's talk about 'aiming left' is that most golfers 'swing along the lines of their body.' So if you want to swing left, it's advisable to aim left to make it easier to accomplish that. But remember, *if* you can hit up with your driver, then you need to 'swing right' to zero out the path. Ben Hogan's stance diagram in his book '5 Lessons' was so brilliant because it shows about where the golfer's feet should be aligned with each club in the bag in order to 'zero out' the 'true path.' Basically I can still hit the inside-aft part of the golf ball and still 'swing left.' However, if I come OTT, then I do not hit the inside-aft part of the golf ball.
The reason why Hogan's diagram works so well is because the AoA gets shallower with the longer the club (usually). A golfer with a -6* AoA with a SW is likely to have a much shallower angle of attack with a 6-iron. And then they are likely to have a much shallower AoA with a 3-wood. So as that AoA shallows out, the horizontal plane moves more towards the right.
3. Why do some instructors want you to eliminate 'shaft lean?'
That's something that golf instructors need to be careful with. Shaft lean = angle of attack. More shaft lean means steeper AoA. So, if you have a lot of shaft lean with an iron, in order to avoid pushes and hooks you need to start swing more left to counter that steeper AoA.
With a driver, it's been basically noted that hitting up with the driver WHILE doing it with shaft lean really decreases your margin for error. Now, Lee Trevino was a great driver of the ball and had a lot of shaft lean, but he clearly hit downward with the driver.
The tradeoff of swinging down with the driver is that you lose distance. Changing from -3 to +3* AoA with the driver can be a difference in about 40 yards even with the same clubhead speed. So, if you cannot get rid of a good amount of shaft lean with the driver and still want to hit it far, I would suggest trying to increase clubhead speed instead of trying to 'optimize driver distance' by hitting upward with the driver.