rawdog, on 03 May 2018 - 11:21 AM, said:
Realizing this will derail the thread, I have to ask...
"In theory, forgiveness is a carney sham."
What's your definition of "forgiveness?"
And what is this "false assumption" of which you speak?
If I'm going to "bank on it," I gotta know!
Ok so before I get into detail I want to state up front that I understand the possibility of there not being much statistical significance to what I'm saying. My bigger point is that there is really zero technical benefit of a "forgiving" iron design "feature". While there is no technical benefit, please realize that I understand that there might not be much of a detriment. Again, main point being is that there is ZERO technical benefit to the supposed claim.
The other thing I'm going to state up front is that the analysis is always going to be a relative difference between a blade and a "forgiving" club design, where one feature or variable will be compared between the two designs while all other variables are set equal. This is the only way to break down a multivariable math system and understand the impact of one variable. Again, just want to state this up front.
Also one more thing to note is that I was fully on board with golf club "forgiveness" and I have bought and tried my share of forgiving clubs and in summary they NEVER helped my game in any way, shape, or form. In fact, for 9 years straight I played a set of mp60 CBs and mp67 MBs with the exact same shafts and specs and not once did the mp60 set give me any amount of "forgiveness". My best rounds were ALWAYS with my mp67s but on average it really didn't matter what clubs I played. I also tried a few SGI mpFliHi clubs for supposed "forgiveness" for two seasons and in short they were horrible clubs. I hit them worse than their equivalent mp60 and mp67. I've also played Mizuno Altron CBs and CG2 and CG4 Clevelands for "forgiveness" and again they had ZERO benefit to me over blades. And finally when I started playing Miura baby blades is when I finally found even more forgiveness than any other club that I've ever played in my life. It has amounted to me shooting as low as 75 and 76 a few times which is better than with any other set that I've ever played. So anyway, to answer the OP first post, I don't ever see a need to play any iron except for a blade design. The blade design is simply the best and it is true every time I try the alternative. So I've quit trying because the science also supports everything I'm saying. A
nd lastly before I really get into things please note that this is my last post and the last time I will read this thread. If anybody wants to debate any of this with me feel free to PM me. But if you do I would first suggest that you read these two books (or the technical equivalent of them by other professors and authors) and also have a complete understanding of the mathematics within them. Meaning, be able to solve the actual example problems within them.
- Physics for Scientists and Engineers by Giancoli
- Introduction to Materials Science Engineering by Shackelford
Everything that I am summarizing with words is already justitified with mathematics from these books, and I really feel that unless you can understand this math, then there is no point in getting into a debate with me about it. Plus I don't want to derail the thread.
Ok so now let me start by stating my definition of forgiveness:
Forgiveness is a design feature that, when compared to an alternative design, results in a tangible benefit to a golfer based on him miss hitting the same shot with both clubs. It also is a feature that doesn't have detriments in addition to the benefits or at least the benefits have a tangible and quantifiable benefit over the detriments. Also the actual science behind the feature is sound and is based on true science and without any false assumptions.
This is about as succinct as I can make my definition of forgiveness. I'm glad that you asked because it is important to understand that it is under this context that I'm claiming that just about every current "forgiving" feature on a "forgiving" iron design is that it is a technical carney sham(e). It's a sham because as stated the supposed features are based on science that requires the ignorant golfer to make a false assumption which makes it completely untrue to begin with. It's a shame because if the lead golf design engineers that are supposedly well educated on the science behind their designs, then they have not addressed all the real world detriments that also come about from the very same feature that they are claiming as "forgiving".
Carney Sham(e) #1 - That perimeter weighting and thus increasing the MOI of the clubhead as it rotates as a free body around its center is somehow helping the clubhead to "twist less" on off center hits.
This is probably the #1 sham(e) in all of "forgiveness" because it is simply the one I've read that is most claimed by players of "forgiving" clubs. One of the false assumptions behind it is that the clubhead will NEVER rotate freely as a free body around the ball independently of its connection to the shaft. The shaft is ALWAYS the resistance point for keeping the clubhead square at impact and so therefore any force on the clubface is going to cause the clubhead to always twist based on rotation about the shaft and never the center of the clubhead itself. Basically, every single impact with the golf ball based on it being offset with the shaft is going to put torque on the shaft to try and make the face twist open. This physics is universal. It won't matter if you hit the face near the hosel or at the toe in both of these locations, the way the physics works is that it will put torque on the clubface with the shaft as the fulcrum of rotation. That "forgiveness" is based on assuming otherwise than this is completely false and completely a sham(e).
The other issue and false assumption with perimeter weighting being "forgiving" is that it also makes the sole surface are of the clubhead literally bigger than a MB which is a complete DETRIMENT! That "forgiving" club designers assume that making the sole of clubhead so big in order to achieve perimeter weighting (and a lower clubhead CG) does not have any detrimental issue with making clean ball contact boggles my mind. The technical issue with a club with a bigger surface area sole (regardless of whether or not it is from length or width) as compared to one with a smaller surface area is that it literally will increase the chances of some part of that sole contacting the ground before the face of the club contacts the ball. This would constitute a fat miss hit. The big ball was hit before the little ball.
I hope this is an obvious issue but LOL just in case let's look at a specific example. Let's say we have a longer clubhead and a shorter clubhead (again with all other things being equal). The longer club naturally has the bigger surface area sole. Now with a perfect swing, the issue with the sole is not an issue. The sole of each club stays above the ground and does not contact it before the face
hits the ball.
Now let's add a specific miss hit to this. Now let's say the clubhead is coming into the ball with the heel at the same height with both clubs but the lie angle of the clubhead is tilting such that the toe is angled more downward than the heel. Now clearly the toe is going to contact the ground first in this example and, furthermore and unequivocally, the longer clubhead toe is going to hang lower relative to the heel than the shorter clubhead toe. Therefore the longer clubhead toe is the more unforgiving clubhead based on sole surface area.
This is just a simple specific example of the issue with a longer clubhead than a shorter one but it also works the same way with clubhead sole widths. The thicker clubhead sole width will also have a higher chance of rubbing the ground before the clubface contacts the ball as compared to a thinner clubhead sole (all other things equal). (Also bounce has the same issue. Higher bounce clubs have a higher surface area on the sole and they too create the issue of increased chance for contacting the ground before the clubface contacts the ball.)
To put it another way more simply: with a bigger sole surface area there is literal mass to hit the ground with whereas there is the absense of the same mass with the smaller sole surface area. And beyond just ground contact, a smaller surface area sole will also cut through all media (grass, dirt, sand, water, etc) better. The sole will rub against any media that it has to pass under it, and so when there is more surface area there will be a greater force of friction on that surface area which will slow the clubhead down. So therefore if you want the least friction as a clubhead passes over any media, then the you need the smallest sole surface area club.
So with respect to sole surface area, the blade design is clearly superior to a more "forgiving" design from perimeter weighting (and lowering the CG).
And furthermore, let's look at the muscle thickness or more specifically the part of the clubhead that will literally come into contact with the ball in the context of having perimeter weighting or not. This part of a clubhead design is important for creating consistent spin. And the reason is because temporary deformation of any material (including the carbon steel clubhead) has a mathematical relation (or relations) that make the material thickness directly proportional to the magnitude of deformation under a given force. What this means in layman's terms is that the thicker the material, the less it deform under a force. And so when you consider the force of the ball pushing into the face of the clubhead at impact, it will be unequivocally true that the thicker face wall will deform the least amount. And so a ball that compresses (which ultimately creates the spin on the ball) against a thick walled face will more consistently compress and thus spin.
By contrast, when the face wall gets thinner and is supported by thick perimeter walls, then that clubface will flex inward more when the ball compresses against it. This will serve to damp the spin on the ball but the real issue with this type of face and clubhead design is that it will make the spin inconsistent in addition to damping it. By analogy, the face will behave much like a trampoline where the flex is the greatest at the middle but then as you approach the edges that side of the ball will not flex as much as the part closer to the middle. When you jump up and down on a trampoline, you will bounce straight up and down if you do it at the very middle. But if you start jumping up and down closer to the edge, you will notice the trampoline will tend to bounce you back towards the middle. And so for a trampoline like clubface, this makes for a varying face angle depending on how close to the edges of that face that you hit it. Net result: more inconsistent spin than the thicker face walled club which again does not flex as much, so it is more consistent.
Now if you really want to get into more details on this, you have to understand the Young's (or modulus of elasticity), bulk, and shear moduli for all materials and the math behind them. If you study the math, you will always see that there is a length or thickness dimension in the formula. I learned about all this from two books I mentioned earlier, but you can also just Google "Young's modulus" and the other moduli and wikipedia has pretty good mathematical details on all of it.
The beauty of the muscleback/blade design really is that thick muscle. As long as you don't hit the hosel or out on the non grooved section of the toe, you can hit a muscle back club anywhere along it and it will be fine or at the very least better than the exact same miss hit with an inconsistent and thin face walled clubface. The muscle is a lot like the thick part of a baseball bat. As long as you use that part to contact the ball, it will impart consistent spin and much of the clubhead's kinetic energy into the ball. The notion (false assumption) that a muscle back or blade clubhead design having the "sweetspot" of a dime is hogwash. There is no law in all of physics that supports this notion. The reality of design is that the whole muscle itself is the "sweetspot"!
So once again advantage goes to the blade design over "forgiving" alternatives by virtue of having a
thicker face wall behind the ball at impact.
Carney Sham(e) #2 - That clubhead toe weighting and thus increasing the MOI of the clubhead as it rotates around the shaft is somehow helping the clubhead to "twist less" on off center hits out at the toe.
The false assumption behind this claim is that the added torque that a higher MOI clubhead has compared to a blade is not a detriment. With blades, the short clubhead length or less toe weighting is an advantage because it puts less torque on your hands as you swing the club itself and during impact itself. By the simple equation for torque and under the same exact swing, as a golfer accelerates the clubhead in the downswing, the added toe weighting literally makes the clubhead twist open relative to the shaft more than a lower MOI clubhead with less toe weighting.length. Ultimately what all this means is that it is easier to control the face position of a lower MOI clubhead as compared to a higher MOI one (as it twists around the shaft). And it is easier both during the downswing and during impact itself. Lower MOI = less torque on your hands.
Carney Sham(e) #3 - That lowering the CG of the clubhead is somehow "forgiving" for a golfer.
The problem with this "feature" is that it the same issue as with perimeter weighting. Everything that I said earlier about issues with perimeter weighting apply to lowering the clubhead CG. In summary it makes the face wall thickness and thus spin more inconsistent and it increases the sole surface area which is unequivocally detrimental (all other things equal). The sham(e) is that there is some created need to "forgive" a golf shot by claiming the lower CG will be "forgiving". Not when it comes with so many detriments.
So once again, advantage goes to the blade design with respect to CG location.
Carney Sham(e) #4 - That higher bounce is somehow helping a golfer by making the clubhead "dig less" on a slightly fat miss hit.
The false assumptions in this "feature" are that there isn't a detriment to bounce and that it is enough to reroute the path of the clubhead over the distance of the miss hit from ideal impact such that it improves the hit as compared to using a low bounce club. The reality with a higher bounce club is that it simply creates a higher drag force on the clubhead through ANY media, therefore slowing the clubhead down more as compared to a low bounce club.
The other reality is that it literally lowers the true "bottom" of the sole relative to the low bounce club and thus per what I already stated about a high sole surface area club this will increase the chances of the club rubbing the ground before the clubface contacts the ball. This is ALWAYS bad!
So once again, advantage goes to blade design (in general...I recognize there are "forgiving" clubs
with low bounce) in terms of bounce.
Carney Sham(e) #5 - That offset is somehow helping a golfer.
The first problem with offset is that it literally offsets the clubhead CG from the shaft, and the problem with this is that when centripetal force takes over in the swing, which it WILL, this offset will cause the clubhead CG to want to orient itself to be in the axial shaft line which will then cause the clubhead to go to a closed position relative to a less offset club. This is why offset clubs cause hooks or mitigate slicing the ball. Now, one could claim that this is helpful, but the problem is that it is a dynamic issue. In order for that clubface closing to be consistently beneficial to a golfer with a slice miss hit is that the golfer's swing and tempo must also be consistent to cause the offset clubhead to close consistently. This is just simply adding variability to a clubhead design where it is not needed.
The second problem with offset is that it literally moves the CG and contact position of the clubhead more out of position when the golfer does not square the clubhead at impact relative to the less offset club. Meaning, as the golfer uses an offset club and he has the face coming into impact either open or closed, the position of that clubface is more "off" than the position of the less offset club with the same open or closed face position.
To understand this more clearly let's look at a baseball bat analogy. A standard bat has zero offset. You can twist the handle and the fat part of the bat stays in the same position. Now add offset to the baseball bat fat part relative to the handle. Now consider what happens when you twist the offset bat handle, the fat part of the bat then rotates and goes up and down in literal space because of the offset itself. The fat part of the bat position is exacerbated with offset which is bad. Same issue applies to an offset clubhead.
So once again, advantage goes to the less offset club which is typically the complete opposite of
"SGI" "forgiving" irons.
Carney Sham(e) #6 - That there is any scientific correlation between "forgiveness" and skill level.
If you notice, nothing in what I said above makes a distinction as to the golfer's skill level. The reason is because all of the science is universal as to the benefits of a blade whether or not how often the golfer hits the miss hit or whether or not how bad the miss hit was. Also as mentioned you can look at the entire length of a blade muscle like the fat part of a baseball bat where you can hit the "home run" with contact along any part that is fat behind the ball (and still on the grooves and FLAT!!!). Compared to a variable flexing thinner face CB, this is much more forgiving.
Ok so that about covers everything from an LOL high level. As mentioned there is deeper math in everything I've stated.
Also I just want to mention that the "forgiving" designs simply damp the feel of a miss hit and if there is any "detriment" to a blade design is that the same exact miss hit simply feels worse on the hands and moreover the subtleties of all different qualities of strike are more distinct with a blade. I think some golfers associate this issue with a blade being more demanding on the golfer and that miss hits are more penal on him, but to me that is demanding in only his mind (because there is no true science to support it) and just because the feedback is so precise. To me this is where the mind f*ck comes into play with those that use a "forgiving" club and think that the miss hit that they just it was somehow "saved". In my experience the same miss hit just feels worse with a blade. Also in my experience a blade design is simply more forgiving even on miss hits.
I'm done here. PM me if you want to discuss further.