I've discovered Maltby's flaw! The truth behind MPF ratings and why they are rating your clubs so lo

Being on a search for new irons that would propel my game to the next level, along with being a bit of a math nerd, I was lead to Mr. Maltby's iron rating system: The Maltby Playability Factor (MPF). I was intrigued. How could you not want to look at a true and unbiased breakdown of how easy to hit, playable as Maltby calls it, golf irons really are? Numbers derived from physics and trigonometry computations and not data provided by the iron maker themselves -- Granted Maltby's irons fared well, but they don't interest me. I was analyzing Ping vs Taylormade vs Cobra vs Mizuno and so on.

Seeing the topic of Maltby's work being scrutinized and ripped apart on this site and others added to the fun, if you can call it that. I wondered how could it be that Callaway's 2016 Apex, a sought after and popular iron, could be classified as, "difficult to play, 0-5 handicap only. No game improvement features?" (https://www.golfworks.com/iron-head-mpf-ratings/a/870/) Man, I just hit those at Golf Galaxy and I thought they were sweet! Why is the MPF so against them.

After analyzing Maltby's data tonight, and what a wild night it was crunching numbers in hopes of getting that magical iron set that allows me to break 80 more than once or twice a summer,I discovered Maltby's error.

First, we can all agree from the physics lesson we all seem to follow as golfers that:

1) Center of gravity low equals high launch.

2) Center of gravity deep in club face equals forgiveness and likely more spin (game improvement features)

3) Center of Gravity forward equals lower spin and less forgiveness (players club attributes)

Second, using this knowledge it would be obvious that Maltby's ratings will award points (awarded for more "playability") for clubs with a lower and deeper center of gravity - as well it should. Just like a Ping G series is easier to hit than an I series, the CG is placed low and back in G clubs for game improvement attributes. So that being said, players clubs with a more forward center of gravity wont score as well. ok we get it. But why are some better player's clubs being ranked as unplayable?

The answer....a simple error on Maltby's part...size of face on iron. Those players irons are more compact and have smaller heads than their game improvement brothers. Why does this matter??

Look here http://ralphmaltby.com/method-of-determining-mpf/

Maltby's mistake is that he is measuring the distance up the clubface where the center of gravity is located in inches from the bottom of the club face. So The callaway apex 2016, and its smaller head, comes in with a CG .871 inches up the face from the leading edge on bottom. The 2017 Big Bertha OS measures .890 inches from bottom edge to CG location. Pretty similar right? But wait! the Bertha OS is an Over-Sized club head. Hence the OS in its name. The Apex is a compact player's iron.

So .890 inches up the larger Bertha OS face might only be 40% of the way to the top of the clubface -- while that same .890 inches may come up 50% of the way from bottom-to-top on the smaller Apex head.

Get it? Did I explain this well enough i wonder? Maltby should measure CG location as a PERCENTAGE of the distance from bottom of clubface to top, and NOT MEASURE in INCHES!! He is not accounting for different sized clubheads!! Smaller, player irons - and their smaller heads - are losing MPF points because of an erroneous CG location being very high on the face. If I made a iron head that was identical in proportion to the 2016 Apex but 4 times the height and 4 times the depth of the 2016 Apex, an iron head the size of a frying pan, it would get exactly 4 times the points under Maltby's calculation - because its not measuring the CG location in terms of percentages or fractions from bottom of clubface to CG location. Did anyone read this whole thing?? My wife did, even she quit before this point :):)

The golfball is the same height for both clubs.

You're not understanding how this works. In the MPF data, the measurement called the "Actual Vertical COG" is the height of the sweet spot from the "ground line". The Actual Vertical COG is the sweet spot. Regardless of how tall the face is, the measurement is always done the same way, because what matters is where the sweet spot is located.

A solid strike in the vertical aspect of contact, is one in which the AVCOG of the head design arrives 'in line with' or slightly below the center of the ball. The COG (center) of a golf ball is .840".

In the MPF formula for the final "score" and rating, any head design that has an AVCOG higher than .840" is penalized. This is because a sweet spot of that height is more difficult to hit solid "in the vertical aspect of contact" for most players,..especially when playing from normal fairway lies

Maltby puts too much emphasis on C dimension and gives no credit for sole grind or bounce. How does club behave dynamically?

Well thought out post. I also poke around the mpf chart when looking at new irons. I will say that I did buy a set of Ping s58 irons that I thought i would not be able to hit only to be proven wrong. The mpf for those was the super game improvement category. Shocking but this supports your post, smaller head but cg is low and deep.

Oh and I did read the whole thing......??

You're not understanding how this works. In the MPF data, the measurement called the "Actual Vertical COG" is the height of the sweet spot from the "ground line". The Actual Vertical COG is the sweet spot. Regardless of how tall the face is, the measurement is always done the same way, because what matters is where the sweet spot is located.

 

A solid strike in the vertical aspect of contact, is one in which the AVCOG of the head design arrives 'in line with' or slightly below the center of the ball. The COG (center) of a golf ball is .840".

 

In the MPF formula for the final "score" and rating, any head design that has an AVCOG higher than .840" is penalized. This is because a sweet spot of that height is more difficult to hit solid "in the vertical aspect of contact" for most players,..especially when playing from normal fairway lies

Well, you may be correct in that I din't know how the entire system works. I did not see mention that points were awarded and clubs were graded when measuring center of gravity in relation to a golf ball. Than, of course, the "ground line" means everything.

Thank you very much for taking the time to read and respond! The only thing better than having a theory that disproves a work that you find flawed is having your theory blown apart..I mean that. Thanks for the effort.

These may help visualize how CG goes down the deeper it is into the head.

You're not understanding how this works. In the MPF data, the measurement called the "Actual Vertical COG" is the height of the sweet spot from the "ground line". The Actual Vertical COG is the sweet spot. Regardless of how tall the face is, the measurement is always done the same way, because what matters is where the sweet spot is located.

 

A solid strike in the vertical aspect of contact, is one in which the AVCOG of the head design arrives 'in line with' or slightly below the center of the ball. The COG (center) of a golf ball is .840".

 

In the MPF formula for the final "score" and rating, any head design that has an AVCOG higher than .840" is penalized. This is because a sweet spot of that height is more difficult to hit solid "in the vertical aspect of contact" for most players,..especially when playing from normal fairway lies

 

Well, you may be correct in that I din't know how the entire system works. I did not see mention that points were awarded and clubs were graded when measuring center of gravity in relation to a golf ball. Than, of course, the "ground line" means everything.

 

Thank you very much for taking the time to read and respond! The only thing better than having a theory that disproves a work that you find flawed is having your theory blown apart..I mean that. Thanks for the effort.

If you're really into this, then Ralph Maltby's book "The Maltby Playability Factor, understanding golf club dynamics" is a must have. It explains everything in great detail. Here's an example from their website...

http://ralphmaltby.com/method-of-determining-mpf/

You're not understanding how this works. In the MPF data, the measurement called the "Actual Vertical COG" is the height of the sweet spot from the "ground line". The Actual Vertical COG is the sweet spot. Regardless of how tall the face is, the measurement is always done the same way, because what matters is where the sweet spot is located.

 

A solid strike in the vertical aspect of contact, is one in which the AVCOG of the head design arrives 'in line with' or slightly below the center of the ball. The COG (center) of a golf ball is .840".

 

In the MPF formula for the final "score" and rating, any head design that has an AVCOG higher than .840" is penalized. This is because a sweet spot of that height is more difficult to hit solid "in the vertical aspect of contact" for most players,..especially when playing from normal fairway lies

 

Well, you may be correct in that I din't know how the entire system works. I did not see mention that points were awarded and clubs were graded when measuring center of gravity in relation to a golf ball. Than, of course, the "ground line" means everything.

 

Thank you very much for taking the time to read and respond! The only thing better than having a theory that disproves a work that you find flawed is having your theory blown apart..I mean that. Thanks for the effort.

 

If you're really into this, then Ralph Maltby's book "The Maltby Playability Factor, understanding golf club dynamics" is a must have. It explains everything in great detail. Here's an example from their website...

http://ralphmaltby.c...etermining-mpf/

How can something explain dynamics by taking static measurements? Also isn't turf interaction part of "playability" Bounce, grind, sole width. MPF seems totally worthless IMO.

You guys need consider the fact that Maltby has a vested interest in MPF numbers.

Is anyone here surprised that Maltby heads have inflated MPF numbers?

You guys need consider the fact that Maltby has a vested interest in MPF numbers.

 

Is anyone here surprised that Maltby heads have inflated MPF numbers?

Would it not be completely ridiculous to research and find what design properties make irons easier to hit solid for most players,.....and then not apply those things to your own brand of irons?

This would be like Taylormade coming out and explaining in great detail, what they've found to produce a better performing driver.....and then not applying those things to their own line of drivers.

Make any sense? :huh:

How can something explain dynamics by taking static measurements? Also isn't turf interaction part of "playability" Bounce, grind, sole width. MPF seems totally worthless IMO.

Don't know but if you ask me I'd rather use the hammer with the bigger head:

 

If you're really into this, then Ralph Maltby's book "The Maltby Playability Factor, understanding golf club dynamics" is a must have. It explains everything in great detail. Here's an example from their website...

http://ralphmaltby.c...etermining-mpf/

 

How can something explain dynamics by taking static measurements? Also isn't turf interaction part of "playability" Bounce, grind, sole width. MPF seems totally worthless IMO.

Do some research, if you don't understand. It's been explained many times. The book is fantastic and will clear up all confusion.

Sole design, is an important factor outside of what the MPF measures. It is looking at "mass and dimensional properties". There are many things that go into a good fitting club,....this is just one area of that

I disagree, he is measuring vertical COG correctly. This has been discussed before, and his measurements are good. The overall score is questionable because:

- He places high value on C-dim, or distance of sweet spot from hosel. This probably isnt a crucial number for better players.

-He places a relatively lower value on MOI, which some would say is an important value.

-He absolutely bottoms out ratings for higher VCOG, but again for better players this probably isnt an issue and the iron may actually have been designed that way on purpose to control flight, etc.

Take your Callaway Apex for example. The MOI is decent, but C-dim is somewhat short at 1.2 inches, then the VCOG is high at .864. Hence the terrible 349 rating. Now compare that to the Epic Pro. MOI is actually pretty low (like a blade), but C-dim is 1.35 and VCOG is .806. He gives it a great score of 589.

I disagree, he is measuring vertical COG correctly. This has been discussed before, and his measurements are good. The overall score is questionable because:

 

- He places high value on C-dim, or distance of sweet spot from hosel. This probably isnt a crucial number for better players.

 

-He places a relatively lower value on MOI, which some would say is an important value.

 

-He absolutely bottoms out ratings for higher VCOG, but again for better players this probably isnt an issue and the iron may actually have been designed that way on purpose to control flight, etc.

 

Take your Callaway Apex for example. The MOI is decent, but C-dim is somewhat short at 1.2 inches, then the VCOG is high at .864. Hence the terrible 349 rating. Now compare that to the Epic Pro. MOI is actually pretty low (like a blade), but C-dim is 1.35 and VCOG is .806. He gives it a great score of 589.

I have also found some strange numbers for a blade,

where the RCOG is pretty low (0.366), but the difference between Basic VCOG (0.815) and Actual VCOG (0.889) is pretty high.

This is only possible, if the sole grind is exceptional in it´s geometry.

Thus, one should also take that into account.

You guys need consider the fact that Maltby has a vested interest in MPF numbers.

 

Is anyone here surprised that Maltby heads have inflated MPF numbers?

He does this as an ability to get the ball airborn. The lower the COG the higher the flight will be and will have the ability to get under the ball and lift it with greater ease, rather than above the centerline of the ball which will produce a lower ball flight and will not become airborne as easily.

Ralph gets high ratings on his heads because he designs his heads around the influence of the COG. His goal during the design is low COG and a good C factor position.

Something is off with some of the numbers however, the nike VPC has a lower MPF than most blades, not sure how thats possible

If you're really into this, then Ralph Maltby's book "The Maltby Playability Factor, understanding golf club dynamics" is a must have. It explains everything in great detail. Here's an example from their website...

http://ralphmaltby.c...etermining-mpf/

 

How can something explain dynamics by taking static measurements? Also isn't turf interaction part of "playability" Bounce, grind, sole width. MPF seems totally worthless IMO.

 

Do some research, if you don't understand. It's been explained many times. The book is fantastic and will clear up all confusion.

 

Sole design, is an important factor outside of what the MPF measures. It is looking at "mass and dimensional properties". There are many things that go into a good fitting club,....this is just one area of that

Keep it up, Cwebb! However, a new generation of "flat earthers" appears every few months. :swoon: Your work is never done.

Is it time for a "i don't understand the MPF therefore it's worthless" thread already? Time goes by so fast!!!

Something is off with some of the numbers however, the nike VPC has a lower MPF than most blades, not sure how thats possible

It's real simple. In general, you can make the biggest cavity back, with the most massive MOI,....but if the sweetspot is located in an area that is hard to find from normal fairway lies, then it will be harder to hit than many small blades.

The center of a golf ball is .840". If an iron has a sweetspot that is .950" high, how many players are going to consistently hit that club solid? Not too many, including the best players.

The MPF is mostly about efficient sweetspot (COG) location. A higher MOI can slightly enhance a good sweetspot,....it does not make up for a bad one

Something is off with some of the numbers however, the nike VPC has a lower MPF than most blades, not sure how thats possible

 

It's real simple. In general, you can make the biggest cavity back, with the most massive MOI,....but if the sweetspot is located in an area that is hard to find from normal fairway lies, then it will be harder to hit than many small blades.

 

The center of a golf ball is .840". If an iron has a sweetspot that is .950" high, how many players are going to consistently hit that club solid? Not too many, including the best players.

 

The MPF is mostly about efficient sweetspot (COG) location. A higher MOI can slightly enhance a good sweetspot,....it does not make up for a bad one

Case in point, the Armour TI-100 all titanium irons heads. I remember when they came out, looking at a set and thinking that they would be eaaaasy to hit. But they flopped because the COG was so high that even good players hit low line drives with them. They made my MP-27's feel like Eye2's in ease of use.

"Playability" in MPF doesn't mean 'how well the head will give draws, fades, and trajectory control.'

Playability means how easy is the club to get the ball airborne.

Any head with the COG nearer the heel and higher is not going to be an MPF superstar due to the fact that few people deloft and hit the ball on the heel side of the face.

"Something is off with some of the numbers however, the nike VPC has a lower MPF than most blades, not sure how thats possible"

The VPC has a COG of 0.929" while the VR Pro forged blade is at 0.815". With the center of the ball at 0.840" you can see that the only way to hit the VPC out of the sweetspot (COG) is to deloft at impact. In plain and simple terms, it is going to be harder to hit regardless of the cavity back.

Something is off with some of the numbers however, the nike VPC has a lower MPF than most blades, not sure how thats possible

Ive always been confused about the word "playability"

I hook, big hooookk, any game improvement iron with slight offset. It feels good, but the accuracy is not there.

I play a blade iron, which lacks in feel (not really, but technically it does) but is super accurate in distance and flight.

I will always play a less "playable" club in this scenario.

Hitting a great feeling, pure...hook into a bunker or the water is not ideal

Ive always been confused about the word "playability"

 

I hook, big hooookk, any game improvement iron with slight offset. It feels good, but the accuracy is not there.

 

I play a blade iron, which lacks in feel (not really, but technically it does) but is super accurate in distance and flight.

 

I will always play a less "playable" club in this scenario.

 

Hitting a great feeling, pure...hook into a bunker or the water is not ideal

"playability" in the MPF, basically means how easy is the sweetspot (COG) to find for most players. For example, a sweetspot that is above the center of the ball and towards the heel, will not be as easy to find for most.....therefore it's considered less "playable"

Ive always been confused about the word "playability"

 

I hook, big hooookk, any game improvement iron with slight offset. It feels good, but the accuracy is not there.

 

I play a blade iron, which lacks in feel (not really, but technically it does) but is super accurate in distance and flight.

 

I will always play a less "playable" club in this scenario.

 

Hitting a great feeling, pure...hook into a bunker or the water is not ideal

 

"playability" in the MPF, basically means how easy is the sweetspot (COG) to find for most players. For example, a sweetspot that is above the center of the ball and towards the heel, will not be as easy to find for most.....therefore it's considered less "playable"

Ahhh, I see. I did play a few rounds with some Steelhead Pros and I found hitting the sweetspot to be less frequent than my sweetspot hits on my blades.

There are too many other factors in the build of a club that are necessary for success

Ive always been confused about the word "playability"

 

I hook, big hooookk, any game improvement iron with slight offset. It feels good, but the accuracy is not there.

 

I play a blade iron, which lacks in feel (not really, but technically it does) but is super accurate in distance and flight.

 

I will always play a less "playable" club in this scenario.

 

Hitting a great feeling, pure...hook into a bunker or the water is not ideal

I would be looking at the lie of these 'big hook' clubs. Everything leads me to believe that the lie angle is simply too upright for you and the face is not pointing down the line.

Playability has nothing to do with even a proper length / lie fitting. When the fit is right - these high playablity clubs will get the ball more airborne with a increased pure backspin and straighter directional control than what a lower rated club will do.

I expect your blades are flatter than the game improvement clubs you have tried (or their lengths may be shorter).

Ive always been confused about the word "playability"

 

I hook, big hooookk, any game improvement iron with slight offset. It feels good, but the accuracy is not there.

 

I play a blade iron, which lacks in feel (not really, but technically it does) but is super accurate in distance and flight.

 

I will always play a less "playable" club in this scenario.

 

Hitting a great feeling, pure...hook into a bunker or the water is not ideal

 

I would be looking at the lie of these 'big hook' clubs. Everything leads me to believe that the lie angle is simply too upright for you and the face is not pointing down the line.

 

Playability has nothing to do with even a proper length / lie fitting. When the fit is right - these high playablity clubs will get the ball more airborne with a increased pure backspin and straighter directional control than what a lower rated club will do.

 

I expect your blades are flatter than the game improvement clubs you have tried (or their lengths may be shorter).

My steelhead pros were 2 flat and they were hook prone

The Steelhead Pros are fine. Your swing is hook prone.

The Steelhead Pros are fine. Your swing is hook prone.

Oh Snap!

:taunt: It wasn't a dig. I fight a hook as well. It ain't the clubs fault I stall and sling it closed.