The Driver Debate Closed: Up vs. Down

[Andrew Rice]

I have posted on this topic a few times and I have finally located what I believe to be the final word on the matter. My philosophy pertaining to whether or not the driver should be hit with an upward or downward strike is simple:
Up=longer and Down=straighter
There is a balance here, so the more you have of one, the more you give up of the other.
Directly from the TrackMan ( www.trackman.com ) website, their January newsletter states:

"The PGA Tour average for attack angle (up or down) with the driver is -1.3 degrees (down). Trackman has measured numbers of up to +6.0 degrees for the two logest hitting players on the tour (Bubba Watson and JB Holmes)."

When you already hit the ball far enough and you play on narrow courses, with long rough, for big checks, it's nice to keep the ball in the short stuff!

In case you don't know TrackMan has more shot data on the PGATour than any other launch monitor, shot tracking company.

That should put this baby to rest Mr. Clampett!

[Leftygolfer]

I would highly doubt for most players that tried to hit with a slight downward strike would not be optimal. I believe that we can not hit it with a square club face like the pros. And when that miss is with a downward strike comes more hook and slice. I know that my best days with my driver I have not broken a tee which is a sign of a level or slight up swing. I have a friend who tees the ball low and back. He has a swing speed of 110-113 and I consistantly keep up with him at a swing speed of 100 maybe 105. We both hit it high but because of his excessive spin he doesn't out drive me (I got him by 20 yards on 18 with no roll and we both hit it well 250-270) I know he is losing 30 yards. Would anyone really give up 30 yards for couple of fairways? I know I wouldn't.

[Surefire]

I would highly doubt for most players that tried to hit with a slight downward strike would not be optimal. I believe that we can not hit it with a square club face like the pros. And when that miss is with a downward strike comes more hook and slice.

Are you sure?

If you hit with a slight downward strike, there would be more backspin, this would reduce the effect of sidespin, not increase it like you are saying. Hence why downward strike has been suggested for more accuracy. However as also mention the backspin would cause a higher and shorter flight, with less rollout.

[ryohazuki222]

Personally, if I break a tee, I assume I'm hitting down.... and if it's unbroken I assume I hit up.

When I'm breaking tees, I hit many more fairways. But my scores suffer as I'm stuck using my long irons.

When I'm not breaking tees, I hit less fairways.... but I score much better.

I'm curious to see how this thread turns out.

[iacas]

Just because Bubba and JB swing up (Phil swings down quite a bit, is anything but accurate, Tiger is down or pretty flat and not terribly accurate but pretty long) doesn't mean we can assume that holds up for the majority of players.

Generally speaking, and as I understand it, "high launch, low spin" necessitates a slightly upward angle of attack.

[Leftygolfer]

No I am not sure. I am actually thinking about it, I am wrong. That is why you hit your 9 iron straighter than your 3 iron. Thanks for the correction. I just know I am not long enough to give up yardage and be able to play long courses and be able to hit greens.

[iacas]

Backspin is not why you hit your 9-iron straighter than your 3-iron.

The ball off of your 3-iron is moving forward through the air (the x vector) at (let's say) 130 MPH. Your 9-iron might be moving forward through the air (the forward component) at 70 MPH.

I'm totally making those numbers up, but I think they get the point across. If you could somehow put the same sidespin on both, the 3-iron would curve a lot more: it goes further and travels faster. Of course the curve will be more pronounced.

Additionally, the 9-iron is a shorter club with more loft, so even if you cut across the ball at the same angle the ball won't compress as much, and thus won't have quite as much sidespin imparted to it as it would with the same angle hit with a 3-iron.

Neither of those reasons have anything to do with "more backspin negating the sidespin." Just basic physics.

Think of sidespin and backspin as two components of spin. Backspin affects shot height (ballooning, "falls out of the sky", etc.) and sidespin affects the curve left or right.

[TheLauncher]

Think of sidespin and backspin as two components of spin. Backspin affects shot height (ballooning, "falls out of the sky", etc.) and sidespin affects the curve left or right.

But if you were able to put significantly more backspin on a ball on an axis online with your target, obviously much more easy with a nine than a three, wouldn't that rotational force help override or reduce the amount of side spin imparted? I'm not sure if I'm making my self clear or not. If you think of throwing a baseball with a four-seam grip, the back spin you create lends stability to the flight.

The points you make about club length and ball speed are well taken, but still I think the effect of loft is significant. Side spin and back spin don't effect the ball independently, but are rather the effect of a singular impact on the ball. Again, I have to think back spin on a ball in line with the target, more easily imparted with a more lofted club, as you have described, is likely to reduce the effects of any side spin created at impact. Although neither of these words seem satisfactory to me, it makes me think of gyroscopic of centrifugal forces.

[iacas]

But if you were able to put significantly more backspin on a ball on an axis online with your target, obviously much more easy with a nine than a three, wouldn't that rotational force help override or reduce the amount of side spin imparted?

No, I believe you're confusing cause and effect.

The loft causes more backspin (as does the angle of attack compared to a driver), but the loft also causes less sidespin due to less compression. The lower speed (due to the shorter shaft, heavier club, etc.) of the 9I also causes less compression. Put it this way: cut across the ball 10 degrees with a driver and the ball's gonna have a lot of slice spin, a lot of forward speed, and will slice quite a bit. Cut across it with a 9I and it'll have a lot less side spin due to the lower amount of compression, a lot less forward speed, and it might cut just a little in flight. You can remove backspin entirely. It's a different vector. Sidespin is sidespin. I used to think that it made sense that "backspin negates sidespin" until I really got into it, both physically and experimentally. It really ends up being more about horizontal ball speed and spin in two axes. Backspin does play a role in terms of horizontal ball speed. Balls with a lot of backspin climb and lose horizontal ball speed, but that's typically much less of a factor than simple air resistance. I suppose it's a pretty pointless debate, though. The take-away is this: you hook or slice clubs with higher loft. Simple enough, and the "reasons why" are pretty unimportant when it comes to actually playing golf.

[imtomtomim]

Well, I tend to have a pretty good image of how the ball spins. Every strike should have backspin. A perfectly on line strike would provide a completely vertical backspin. Sidespin is actually a result of that backspin being angled. The reasons listed by iacas explain how spin is imparted. If you're cutting from the inside out (as a right hander), the ball will rotate from the top left of the ball to the bottom right. Now, the more you cut across the ball at impact, the more that line of rotation will re-angle and make a move towards horizontal. The more horizontal it is, the more the ball flight will cut. Yes, hitting down on the driver CAN make you more accurate, but you don't have the forgiveness that loft gives you (a more vertical backspin). While putting more spin on the drives can theoretically cut off some sidespin generated by an upward strike, you are also trying to spin the ball more, which will exaggerate your mistakes. I try to drive like I'm hitting a baseball bat, smacking the ball somewhere. With my other clubs, I'll try to "spin" the ball with the descending strike because loft will grant me more backspin easier, but with driver, I'd rather hit the ball up and out. Distance accuracy could definitely benefit from controlling the backspin with the driver on a downward strike giving you a little ballooning tail and soft landings, but I just try to play for a 20 yard landing zone (think mario golf grid)

[Ziophils]

I believe side spin and back spin to be related. If you draw a line round the equator of a golf ball and rotate the golf ball in your hand with only side spin the line will stay in the same position. If you start to introduce backspin as well to this ball that line is going to move downwards and away form centre thus reducing sidespin. Maybe not the best explanation but there it is.

Kinetic energy on the ball = 1 and this number 1 is made up of both side and back spin.

[RC]

Couple of things I think are true.
(1) tees breaking... a ball hit high on the club face is prefered (with a driver) so I think the ground firmness is the main factor in whether a tee breaks. The sole of the driver is going to hit the tee swinging up if contact is optimum.
(2) there is little doubt swing slightly up at a driver produces longer drives with less spin in the vertical plane. Side spin is a function of club face angle and swing speed. You can hit them crooked and slicing either way. I don't think hitting down on a driver offers any advantage I can find.

[iacas]

If you're cutting from the inside out (as a right hander), the ball will rotate from the top left of the ball to the bottom right.

It depends on your frame of reference, but if you're behind the ball looking at it fly away from you, you've got it backwards: the spin is from top right to bottom left.

Kinetic energy on the ball = 1 and this number 1 is made up of both side and back spin.

Huh? [sarcasm]I always thought it was pi^e?!?![/sarcasm]

Side spin is a function of club face angle and swing speed. You can hit them crooked and slicing either way. I don't think hitting down on a driver offers any advantage I can find.

Right.

Look, guys, I'll say what I believe (and what has been proven to me as far as I'm concerned): it's loft that helps a ball curve less. I can understand how backspin is throwing so many people off, but added backspin is also a result of added loft. I suppose you could call backspin and less curvature "paired results" or something, but they are not cause-effect. Again, this makes sense from not only a physics standpoint, but experimentally (i.e. real-world) as well. It's difficult to separate the fact that every time you hit a higher shot it curves less than a lower shot, but if you stare at a launch monitor and view Trackman readings for a few days straight, and really chart all of the numbers, I promise you it works out. But in the end, knowing (or not knowing) why your 9I curves less than your driver really doesn't help you play better golf. Knowing it curves less helps, but knowing WHY doesn't. So, mental exercises aside, I'm tabling that part of the conversation (and obviously I only speak for myself, but I encourage everyone else to as well). I would like to have seen a more statistical breakdown of angle of attack versus driving distance, though. Again, Phil hits down on the ball quite aggressively with his driver and yet has streaks where he's as wild or wilder than a lot of guys from the tee. I think Fred Funk has a positive angle of attack on the ball, yet is one of the shorter, more accurate hitters. Even a scatter plot would be interesting: angle of attack versus driving distance and angle of attack versus driving accuracy.