Irons.....launch angle, spin, drop angle, distance

Quote:

Originally Posted by logman 

So I was looking at some manufacturers blurb about their new irons and one of the selling points was "lower spin design". Yep more distance through lower spin. 

 

WTF.....I would have thought that the last thing anyone would want in an iron is low spin. Am I completely wrong here? I would have thought that in an iron trajectory, the most advantagious ball flight would be high launch, high spin. Wouldn't that mean that the ball spins up and lands with a more "straight down" trajectory, so the ball stopped on the green and didn't kick on like a more low spin ball flight would do. 

 

Just recently one of the members here posted some trackman numbers relating to which shaft was the best. The figures were interesting. Shaft A was like 150 meters, 3500 spin, more vertical descent angle, and 4 yards run on. 

                .Shaft B was165 meters, 2900 spin, less descent angle, and 8 yards run on.       

                . PS. these aren't the numbers but you see what I'm saying?

I think the choice should be shaft A. 

 

If you've got 8 yards run on your in the back bunker. And I know in Melbourne at the moment you have to hit high sand irons to get them to stop( I exagerate) but you know what I mean. It'd mean 6 iron up to 3 iron would be virtually unusable because they'd just run through the green.

 

Low spin irons, I'm confused!

This is a good question, so for anyone who is curious:

Players who generate a high ball speed and high spin certainly don't want or need more spin. They back the ball off the greens sometimes, which is never good. Kyle Stanley lost the Farmer's insurance Open in 2012 because he did this. But even the best iron players on tour, hitting off a tee, rarely get the ball to stop with anything over a 5 iron. The best they can do is usually like 12 feet of roll depending on the greens, and anything that stays on is considered good. This is the ball's fault and not the players. Back in the days of balata, you could check up longer irons easier, but it's worth the loss of control 175-225y these days, since the driver is so important. That distance range is just really unimportant, since the short irons are the scoring clubs.

So the lower spin in that part of the set is designed to help with gapping, wind performance (both a lower apex and lower overall spin will keep it straighter in a crosswind), and to keep the flight and iron design consistent with the set. If you really want the ball to stop, there are shaft options, hybrids, and high spin balls to make it work. High speed players often get hurt by too much spin in the short irons, so many balls are designed to have just enough to check with about a 7 iron. After all, long hitters don't need more than a 7 iron on a 450 yard hole, and any time they need a long iron, you can bet their short hitting opponents will need a wood or something.

The other side of things is that, if you're a high ball speed player, you don't need as much spin to stop the ball. It's not the ball spinning like a tire that makes it stop entirely, a lot of it is the slope and the landing angle.

To illustrate this, take a golf ball on the practice green to a flat spot: throw it gently underhand with no upward arc from waist or shoulder height, getting it to land with a shallow angle. It will bounce softly and roll with 80% of its original momentum like a bowling ball. You could throw it soft or hard, it will still bounce roughly the same way as long as the landing angle is shallow, just roll farther. If you took it and threw it at a 45 degree or steeper downward angle though, it will make a pitch mark and a thumping noise, bounce, lose a lot of momentum, and roll only a bit. You could throw it gently at this angle, or you could hurl it with all your might (the greenskeeper might skin you with a rake), much of the speed will be absorbed by the ground regardless of whether it's spinning or not. So really the landing angle is a big deal, not just the spin itself. The catch is that more spin will result in a steeper landing angle as will a higher apex due to the ball slowing down and gaining lift from the dimples. But as you can see from this experiment, even a high ball speed with low spin can stop reasonably well as long as you get some height under the ball at some point.

Backspin can check up a ball mostly by itself, or even back it up. But you don't technically require that much of it necessarily to get a playable action on the greens. Bunker shots and fancy pitch shots are another matter since they're such a short range you can't generate as much height or ball speed, so the energy from the spin can actually give the ball some traction on the green.

If you hit it like Rory or Tiger, your 4000rpm with a 6 iron or so might get your ball to reach 120 feet or so of height because of all the ball speed. Any ball landing from that height will usually be slowed down from the air resistance and lose a ton of energy when it lands, especially since the ball gets so much lift. Joe Schmoe might get 4000rpm with that same 6 iron and only get 70 feet of height, resulting in a ball that doesn't slow down or have as much hangtime before landing. He'd need more spin to achieve a good shot, but Tiger would balloon, lose distance, and get his ball to tear off the front of the green if he had that much more.

That's why hybrids are popular; they could launch and spin exactly the same as the equivalent iron, but they produce much higher ballspeed. That alone will give the ball a higher and better flight. Of course, they often do have more spin and higher launch as well, given that most are marketed at weaker players. Good players can also hit an iron harder, especially the short irons, if they want more height and spin. It's very hard, however, to take spin off without losing power, so some might opt to set up for low spin. Tour players will often play a high spin ball to allow for shots around the greens (because there's really no substitute for a urethane ball 40 yards and in), so they might even need even less spin on their longer irons.

As far as the marketing side of things:

-Bad players who slice interpret spin to mean "sidespin" (which is really backspin on an axis), so they think wrongly that the irons will be somewhat anti slice. These players also often think backspin is a specialty shot when in fact it's incurred on every shot. 

-Loft is still the number one source of spin and trajectory, so jacked lofts can be made to sound appealing by saying they're intentional to lower spin.

-Distance sells, so they prefer to tailor their mass market irons to max distance to make money. If you're good enough to worry about how your ball lands on the greens, not just praying you'll be able to find it, you're a bit higher calibur of player than they market to with these sets. That said, game improvement irons are usually high launching and produce higher ball speed than blades or players designs, so they do compensate for the low spin. The perimeter weighting that makes them forgiving also affects spin.

So long story short, you've got the right idea, but there are tradeoffs. You're trading one type of control for another at the end of the day, whether you have penetrating irons that fly straight and long in the wind or those that drop and stop. But there are other ways to get a slightly steeper landing angle without more spin.

Well run on depends on the conditions, if your looking at hitting an iron onto a fairway, yea. If your looking hitting an iron into the green, not so much. 

As for backspin, its a bit tricky because the physics are a bit much. Backspin actually helps keep the ball in the air longer, so it can increase carry. Professional's want lower backspin on the driver because they can balloon shots alot more than amateurs can. Amateurs with slower golf speeds, need more backspin to get more carry. 

As for irons, I can see a progression from longer irons (less spin grooves), to shorter irons (more spin grooves), wedges are specifically made for more spin. So i can see that logic. As for a professional, i rarely see them back up an iron shot that is above a wedge, but of course they can control the spin, ad more or take it off. 

But for Amateurs, i would just want irons that get me a consistant distance with each iron. For slower golf speeds, irons that tend to hit the ball a little bit higher, so they stop sooner. I guess the trick is, getting the right combination of spin, distance, and shot height, because you wont be holding greens if you don't. 

Quote:

Originally Posted by logman 

Nice! LW! So a little bit more. If I was to hit two clubs . 1 a Mizuno blade.....6 iron at say 85 mph I'm assuming my spin would be lowish, 3000 or such like. the trajectory would be low and boring, with a shallow angle of descent, which would lead to a run on greater than.....2. a ping g15 6 iron also 85 mph. 

I'm assuming the ping would have a higher spin.......and a higher trajectory. Is that right?

Is the higher spin of the ping generated because of the wide sole design?

 

So as to marketing and matching the right clubs to the right player, it would be more advantagious to match to the players swing speed and not to whether they are a mid handicapper or a low handicapper. 

All things being equal, the ping would get slightly higher ball speed on average, launch higher with more max height, and land a bit softer even with slightly stronger lofts. The spin would probably be higher if they are set up with stock shafts, since the Ping is geared for higher cappers who need more spin and launch as a general rule. Perhaps that same blade being struck harder would stop just as well, since swing speed is a major source of spin.

http://www.flightscope.com/index.php/Technology-Explained/trajectory-optimizer.html  This is a nice simulator, it doesn't specifically state landing angle, but you can see the line on the side view. Change to imperial units, put in about 130BS, 3000spin, 12 launch, show the shot, then change to 15 launch. You can see the large increase in carry as well as max height, and also the landing angle and hangtime. If you change the ball speed to 180, which is an absurd number, you'll see the landing angle get even steeper and the flight get higher. That kind of drive would only roll a few yards, despite all the speed at launch.

I expect that the GI clubhead design would lower spin slightly on center hits, due to the high MOI (weight being moved to the perimeter) reducing gear effect. But I could be wrong on that bit, since I don't actually listen to the equipment companies. They could come up with a way to make any feature sound good. Case in point, the Wilson Fat Shaft. Makes it impossible to use the heads with anything but the stock shaft. Yet they claimed the wide tip made it straighter...

As far as your last point, I'd say it's not quite that simple. Match to the swing speed, but also the player's launch angle and spin characteristics. And it's more accurate to match to the player's ball speed rather than swing speed, so that their poor contact won't result in as bad of a flight. If they do make poor contact, even at high speed, it's better to either recommend lessons or give them a more forgiving head; though they'll get better results some of the time their misses will benefit from the GI head. If they're a low handicap and strike the ball well, their trajectory is more consistent and they don't need as much forgiveness.

Remember you can get shafts and balls that provide adjustments to flight as well, so the forgiving head can be paired with a lower flying ball and shaft to give them forgiveness without an overly high flight.

Quote:

Originally Posted by logman 

Given that the use of irons is almost exclusively for hitting greens, and the best condition for the descent would be vertical or close to it, then why wouldn't most golfers insist on the highest spin possible before "ballooning" starts to occur. I guess PW, 9 and possibly 8 are always going to stop because of the descent angle caused by the club angle. But shouldn't 7,6,5,4 be engineered for max spin  to reduce the rollon as much as possible. Or is this what the engineers are doing allready?

6, 5, and 4 are seldom able to stop in less than 6 feet off a flat landing spot unless the player hits off a tee, sets his equipment up to produce more height such as adding hybrids, or tries to change his technique to hit it particularly high. Trackman results from a number of tour players indicate that they roll their irons a few yards on average:

So this shows they're willing to accept 12-24 feet of roll on their long irons. The hybrid entry isn't really accurate since it's a composite of lofts 15-18 degrees which is 2 iron or 5 wood replacement, not the 3 iron. Add say a degree of launch and 3-4mph of ball speed to simulate a hybrid 3 iron, it would still take 20-30 feet to stop. And you can see that they miss left and right by about 30 feet in either direction with long irons. Then you can also look at the LPGA, who are barely able to get a 45 degree landing angle with their irons. They're averaging only a 43 degree landing angle with the 4 iron, and 30 feet lower max height and 1.5 seconds less hangtime. This in spite of the fact they make great contact, launch considerably higher than the men with about the same spin in that part of the set. They struggle to produce enough spin due to their low swing speeds, in fact. You can bet the ladies are getting fairway wood type roll on their long irons, and they still score OK.

Most of the time they just want to be able to putt it, and be on the same tier of the green, even if it's a 30 footer. Par is the name of the game on par 4s of this length, and many players will be thrilled to make par on a 200+ par 3. They score by attacking par 5s, so they are willing to give up the ability to make eagles to make 2 putt or up and down birdies on half the par 5s. They get some chances on short par 4s, and usually expect to make a few putts on the holes they wedge onto, but they rarely get mad at making a 4. They can get worked up over a par on the par 5s though.

http://www.pgatour.com/content/pgatour/stats/categories.RAPP_INQ.html Check the statistics for things like GIRs from 175+ and proximity to the hole from 200+. Make sure to select 2012 though, since the numbers are skewed this year; there's only been a couple tournaments.

It might interest you to know that the best players in the world from this 175-225 range are, fairly safely, Tiger and Rory. Tiger doesn't even reach the green with his long and mid irons 2/3 of the time, and he's a really long iron player so that includes even his 7 and 8; he led that category by a fair bit and many players were barely able to do it half the time. Rory was the second best on proximity from the fairway, an indication of how far from the hole he averages from 200 and above. He averaged 34 feet from 200-225 and 30 feet from 175-200. And this is off the fairway from good lies, mind you. Really really good, but maybe not what you'd expect considering his dispersion could easily miss the green even when he goes for the center. He really can't go at flags from that range unless it's wide open. Rory won the US Open in stunning fashion because the greens were so soft that year that he just knocked over pins all week. The average tour player, meanwhile, is considering laying up and only his pride and his faith in his short game is stopping him.

Even on GIRs from 125-150, which even hackers consider to be scoring range, the very best average hitting the green at all only 80%, and anything over 70 is considered good.

They don't show all these lousy shots on TV... Tour players, when compared with what we picture their skill level to be, suck with the long irons because they can get away with it. And this is the best of them, the worse long iron players can't even hit the freaking green with a 6 iron half the time FROM THE FAIRWAY! From the rough, only the best players can manage to stay in control. Partially because long iron proficiency correlates to swing speed; you see Tiger, Rory, Bubba, Garrigus, etc generally lead this category while your shorter types generally need to strike the ball well to be average. Even Luke Donald is pretty average, with the exception of 2012. 

So unless you're planning on taking the professional tours by storm, absolutely forget about stopping your 2, 3, 4, 5, and 6 iron within 2 yards of landing. Even the 7 and 8 will generally release a bit. You only have a problem if you're running the ball through the green more than a few yards with your short irons. We amateurs also play on pudding greens by comparison, where tour greens are often quite nasty. Anything with a makeable putt from mid iron distance is really good, even a chip with a clear angle gives you a shot at a birdie.