620 MB more forgiving than ZXi7?

[Lloyd_Christmas29]

I had an interesting find looking at the Maltby MPF ratings. Looking at the MOI column, the 620 MB is higher than the ZXi7 irons. Interestingly the Z-Forged 2 is also higher MOI as well.

 

Could that be an error? Anyone have experience with these heads that aligns with the numbers here? 

[Pnwpingi210]

3 minutes ago, Lloyd_Christmas29 said:

I had an interesting find looking at the Maltby MPF ratings. Looking at the MOI column, the 620 MB is higher than the ZXi7 irons. Interestingly the Z-Forged 2 is also higher MOI as well.

 

Could that be an error? Anyone have experience with these heads that aligns with the numbers here? 

620 is a much much much more compact head.  The zx7 looks like a ping eye 2 next t two it ( I own both)

 

In no world is the 620mb more forgiving overall than the zxi7.  

[Red4282]

Moi means very little when comparing these type of heads

[Pepperturbo]

17 minutes ago, Lloyd_Christmas29 said:

I had an interesting find looking at the Maltby MPF ratings. Looking at the MOI column, the 620 MB is higher than the ZXi7 irons. Interestingly the Z-Forged 2 is also higher MOI as well.

 

Could that be an error? Anyone have experience with these heads that aligns with the numbers here? 

I have been playing blades since the 90s and tested Zxi7, though its cavity back is shallow, it's large and still has one.  Look at the MPF difference. 

 

I have played 620 MB from 2019 to 2023 when I got T100.  Nevertheless, recently put MBs back in the bag for a few rounds.  They feel very different from Zxi7 and T100.  It's suggested differences like that are WHY I don't pay much attention to Maltby's ratings.  

[Lloyd_Christmas29]

36 minutes ago, Pnwpingi210 said:

620 is a much much much more compact head.  The zx7 looks like a ping eye 2 next t two it ( I own both)

 

In no world is the 620mb more forgiving overall than the zxi7.  

Is MOI relative to head size? If the MOI is the same, wouldn’t you have the same useful area on the face with both irons? And because the ZXi has a bigger head, wouldn’t that just mean more dead space on the head? 

Edited May 20 by Lloyd_Christmas29

[Ger21]

Maltby's MPF is supposed to tell you how forgiving the clubs are. Going by MPF, the ZXi7 is almost twice as forgiving as the 620MB. According to Maltby, at least.

[Pnwpingi210]

5 minutes ago, Ger21 said:

Maltby's MPF is supposed to tell you how forgiving the clubs are. Going by MPF, the ZXi7 is almost twice as forgiving as the 620MB. According to Maltby, at least.

That makes much more sense

[Lloyd_Christmas29]

18 minutes ago, Ger21 said:

Maltby's MPF is supposed to tell you how forgiving the clubs are. Going by MPF, the ZXi7 is almost twice as forgiving as the 620MB. According to Maltby, at least.

I think about it more as “easy to hit” vs forgiving. Or how accessible the sweet spot is off a tight fairway lie. Higher sweet spots get docked points, also the closer the sweet spot is to the heel loses points.

 

If MOI is the same in 2 heads, a strike 1/2” toe side from the center of mass should produce the same result no?

Edited May 20 by Lloyd_Christmas29

[Lloyd_Christmas29]

I try to look at the measurements rather than Maltby’s playability rating. Like VCOG is an objective data point that can be measured. But the MPF is a subjective rating based on what Maltby thinks is easy to hit. Maltby says a low VCOG is easier to hit, but what if you’re really steep, or hitting out of a fluffy lie? I would argue that you would benefit more from a higher VCOG here.

[Pnwpingi210]

16 minutes ago, Lloyd_Christmas29 said:

I think about it more as “easy to hit” vs forgiving. Or how accessible the sweet spot is off a tight fairway lie. Higher sweet spots get docked points, also the closer the sweet spot is to the heel loses points.

 

If MOI is the same in 2 heads, a strike 1/2” toe side from the center of mass should produce the same result no?

No.

 

Go to your store local store.

 

grab 620 mb and zxi7 

 

grab ruler

 

mark on face the same point of center on both irons.

 

go strike it there and report back.

Edited May 20 by Pnwpingi210

[rsballer10]

Whether or not the MPF is useful or not is debatable. There are many different opinions on what variables make an iron easy to hit. The problem is people are sold MOI,MOI,MOI as being the be all and end all to playability. It definitely helps, but others will cite VCOG. MFP is driven by "C" dimension, or horizontal CG distance from the center of the hosel.

 

My head's already spinning. What I've found is that a little "help" (lower VCOG, more MOI, bigger "c" dimension) goes a long way, but has diminishing returns up to a point. I've found "GI" irons to be playable as long as the VCOG doesn't get too high. Ironically, some irons marketed as more forgiving actually have higher CG's, which some describe as harder to hit (me).

[Cwebb]

7 hours ago, Lloyd_Christmas29 said:

I try to look at the measurements rather than Maltby’s playability rating. Like VCOG is an objective data point that can be measured. But the MPF is a subjective rating based on what Maltby thinks is easy to hit. Maltby says a low VCOG is easier to hit, but what if you’re really steep, or hitting out of a fluffy lie? I would argue that you would benefit more from a higher VCOG here.

 

A lower AVCOG and longer C-dimension provides more face area to work with for relatively solid impact.  This is why they are rated higher.  It's a generalization for an easier to hit club from normal to tighter lies,... not a guarantee for an ideal ball flight from every lie condition

[Red4282]

16 hours ago, Lloyd_Christmas29 said:

I think about it more as “easy to hit” vs forgiving. Or how accessible the sweet spot is off a tight fairway lie. Higher sweet spots get docked points, also the closer the sweet spot is to the heel loses points.

 

If MOI is the same in 2 heads, a strike 1/2” toe side from the center of mass should produce the same result no?

Mpf ratings are heavily weighted by vertical center of gravity, and the cdim, so yes you are correct with first paragraph. As to your second, moi in irons just isnt making a huge impact, at least when we are talking these irons. Yea they will twist, and moi is a direct measurement of that twist, but not necessarily how “forgiving” it will be. There are other ways to make a club forgiving on mishits, such as thinning the face in areas to provide a speed boost that is lost from twisting. A MB isnt doing that

[NRJyzr]

16 hours ago, Ger21 said:

Maltby's MPF is supposed to tell you how forgiving the clubs are. Going by MPF, the ZXi7 is almost twice as forgiving as the 620MB. According to Maltby, at least.

 

That's how people use it, but MPF final score is little more than C-Dimension minus Actual VCOG.  There's nothing much about "forgiveness" in that type of arithmetic.  IMHO of course 😉

 

[Ger21]

59 minutes ago, NRJyzr said:

There's nothing much about "forgiveness" in that type of arithmetic.

To me, forgiveness is nothing more than a couple yards on toe strikes.

[Streuner]

Sometimes the MPF ratings are a little strange. I have seen it more than once that a blade or cavity Style Iron head get better (higher) MPF ratings then a (in theory) more forgiving head from the same manufacturer. 
 

take Takomo as example, the 201 head is having a lower rating than a 301 head but all players that have used both are telling the opposite like Takomo supposed 

or Mizunos MP5 and MP H5 

Edited May 21 by Streuner

[NRJyzr]

1 hour ago, Streuner said:

Sometimes the MPF ratings are a little strange. I have seen it more than once that a blade or cavity Style Iron head get better (higher) MPF ratings then a (in theory) more forgiving head from the same manufacturer. 
 

take Takomo as example, the 201 head is having a lower rating than a 301 head but all players that have used both are telling the opposite like Takomo supposed 

or Mizunos MP5 and MP H5 

 

With apologies for repeating myself...

 

C Dimension and Actual VCOG are represented in thousandths of an inch.  Multiply both of those by 1000.  Take CDimension * 1000 result and subtract from that the Actual VCOG * 1000 result.  There's the main portion of the score.

 

Takomo 301:  1152 - 777 = 375.  They add 25 pts for the MOI (it's a sliding scale for MOI that's reduced as the CG gets higher).  Then add 30 points, because they add 30 points for every clubhead.

 

Takomo 201:  1115 - 809 = 306.  Add 13 points for MOI, notice it's a smaller addition than what's given to the 301 in spite of the 201's MOI being greater.  This is because the CG of the 201 is higher.  And, the always added 30 points, you get 349.

 

That's really all there is to it.  Nothing mystical.  If you look into GolfWorks site under Technical, or the Ralph Maltby site, you can find the explanation of how they do the calculation.

 

 

Edited May 21 by NRJyzr