
What is Moment of Inertia? How does it help you? Is there a magic number that makes something perform better or offer more? Where did 10K MOI come from? These are all questions that have been brought up since the beginning of 2024 on the THP Forum and social media.
Earlier this month, we took a detailed look at the new Mizuno ST-Max Driver. Breaking down how it was constructed and what you might expect out of the performance. What is the MOI of this driver?
Rather than explain it, we sought out one of the industry experts to walk through what is real and what isn’t and what you can look for in a driver. In this video, Chris Voshall from Mizuno Golf goes over the magic number of 10K MOI and if it matters?
With all of the buzz words and marketing that has been done around 10K and MOI, after watching Chris Voshall go over the ST-MAX and MOI in general, where do you stand on it?
Marketing buzz words or something that you are searching for to help your game?
For more information on Mizuno Golf or any of their products, check out their website at www.mizunogolf.com.





Will give this a listen in just a bit.
Cannot wait to listen to this one when I get to my desk
Been waiting for this!
Interesting. It’s always interesting to hear about the decisions manufacturer’s need to make about the give and take between forgiveness and appearance and other properties. Thanks.
Great listening to what cause and effects occur when building a club. When do we get a 11800 club?
Great description. Hard to square up?? That part had my confused for a minute :unsure:
He just breaks it down so well. He always does and I really enjoy his videos.
Great listen and truly appreciate how Chris broke down MOI and what actually goes in to getting to that number. I never really thought about how the shape of the club is effected by it.
Good stuff!!!
[QUOTE=”golfinnut, post: 12214293, member: 21902″]
Great description. Hard to square up?? That part had my confused for a minute :unsure:
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It is something we mentioned during our PGA Show coverage as well after speaking to a couple of different R&D people.
Definitely going to give it a listen after I get some of the morning routine sorted
Been waiting for this one to drop. So good, and SO educational on the whole 10K thing.
Great listen, learned a few things I did not know. It certainly tells the story to make sure to get fit before buying just on the tech story. Did not know there were sacrifices that had to be given up to achieve 10K.
Great video! I love this chat as marketing never talks about what is given up to get what they’re marketing and there is always a trade off somewhere.
I always enjoy learning more about golf club design and MOI. I will listen to this today.
Tusks thatTIP for captioning it helps me a lot thanks Chris Voshall for explaining all this as well.
For me the magical 10k is not worth that trade offer that Chris noted. Also diminishing returns. I wonder how much different say 9400 is thank 10k. If the shape is off putting our spin is too high or tut fcc is closed is it going to perfom better, not likely, for me.
[MEDIA=youtube]RBH7NtdIfI8[/MEDIA]
Good watch and listen. Definitely educational about things when it comes to MOI… I’m very interested in the Max. I’d like to see how that might make a difference for me.
I’d love to spend a day with a guy like Vosh. Well, I guess we have quite a few people that have done that and will get to do that later this year lol.
It’s a very interesting discussion. I took away that there’s no free rides in golf club design and you have to find the best compromise for your target player. It makes sense to me that a club that wants to resist twisting is going to experience slower closure rates. At least that’s where my mind is at.
What a fantastic video. So well explained. Everyone can learn a lot from this.
Love this. I’m a firm believer in the CG – closure rate discussion.
Makes me want to go hit this one as I haven’t yet.
This is so freakin interesting. One of the better explanations of MOI I have seen. When are the manufacturers going to start publishing these numbers in the specs
Chris makes me feel less stupid lol
Lol, I had just watched this on You tube while running a report for work…..and all of a sudden Chris started in about Moi and 10K and i was locked in for the rest of the video, great explanation and Masters class on why you do or don’t want “10k”
Great video Chris explains it so well. I love listening to him. The fact that they stayed under 10k on purpose is interesting. Details on what has to change and the effects on changes to get to 10k was very insightful.
The 10K hype means very little to me. Give me a driver that works and I’m happy.
[QUOTE=”donny475, post: 12214393, member: 4683″]
Lol, I had just watched this on You tube while running a report for work…..and all of a sudden Chris started in about Moi and 10K and i was locked in for the rest of the video, great explanation and Masters class on why you do or don’t want “10k”
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okay, i will admit, i watched it twice cause i wanted to make sure i understood the whole Voshall Ted Talk on MOI and 10k
My question about MOI is are all OEM’s measuring it the same?
[QUOTE=”PhillyV, post: 12214411, member: 6890″]
My question about MOI is are all OEM’s measuring it the same?
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This is where I’m at, in addition to would be curious how the MOI is broken down in these is it 5,900 on one plane and 3,300 in the other or evenly split on the Max?
[QUOTE=”Golfers Anonymous, post: 12214433, member: 59233″]
This is where I’m at, in addition to would be curious how the MOI is broken down in these is it 5,900 on one plane and 3,300 in the other or evenly split on the Max?
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I’m not going to say I know for certain, but if the USGA is regulating MOI there has to be some sort of standard for measurement.
[QUOTE=”PhillyV, post: 12214411, member: 6890″]
My question about MOI is are all OEM’s measuring it the same?
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Generally speaking, yes.
Great video and I love how he breaks it down so that I can actually understand what he’s talking about. Thanks for doing this THP!
[QUOTE=”Hawk, post: 12214439, member: 1193″]
I’m not going to say I know for certain, but if the USGA is regulating MOI there has to be some sort of standard for measurement.
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More curious if the manufacturers have their own to use during design and when they produce their own products. The one the USGA and R&A use is by Auditor I believe, but didn’t know if the manufacturers have there own “standards” they use that’s different from everyone else.
Good vid. Makes sense.
If there ever was someone to help explain MOI and golf club design in general, Chris is one of, if not the best to explain as simply as possible and still hitting the key points. This is a great video and I enjoyed how he basically took the bias out of the message and gave facts on why and what happens when chasing MOI.
Awesome video, learned a lot in a short time.
Was one of the coolest things I learned at the show when it comes to 10K and actually squaring the face.
Chris explained it well but it’s still all marketing. “10K not that great, but 9.5K is the best because that’s what we’re doing.” When Mizuno does 10K, they’ll just say they figured out how to reduce spin and improve looks.
[QUOTE=”dunkjez, post: 12214662, member: 15068″]
Chris explained it well but it’s still all marketing. “10K not that great, but 9.5K is the best because that’s what we’re doing.” When Mizuno does 10K, they’ll just say they figured out how to reduce spin and improve looks.
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How is that what you took from that video? He never said 9.5 was best, he explained why they don’t do 10k, that’s honesty not marketing
[QUOTE=”dunkjez, post: 12214662, member: 15068″]
Chris explained it well but it’s still all marketing. “10K not that great, but 9.5K is the best because that’s what we’re doing.” When Mizuno does 10K, they’ll just say they figured out how to reduce spin and improve looks.
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I genuinely dont think that was his message or intent here.
It was that they have a number of different drivers as does everybody and chasing a MOI number isnt ideal.
For instance if someone doesnt care about offset or spinny or shaping or upright, some models may be great for them. Others may not want that, and that instead of just chasing a number, looking at it objectively through data and performance is the best recipe for success.
He certainly isnt saying 9500 is the best, as they have models as he mentioned well below that.
[QUOTE=”dunkjez, post: 12214662, member: 15068″]
Chris explained it well but it’s still all marketing. “10K not that great, but 9.5K is the best because that’s what we’re doing.” When Mizuno does 10K, they’ll just say they figured out how to reduce spin and improve looks.
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I took the complete opposite from the video. I heard him say 10K is good but comes with sacrifices. Having sat in a room with Chris and picked his brain on all thing club design, he is the first to say he will not hit a “buzz word” or “marketing gimmick” just because. Mizuno operates really lean and any market share they grab they cherish and take seriously so messaging is as forthcoming and honest as any OEM IMO>
This video has so much information in it, and explained in a way that is so easy to digest, it is incredible.
I would imagine the counter argument that 10K is better, by TM and Ping would be “because we perfected it”. But maybe not explaining the overall repercussions of hitting that number.
Being more informed about golf tech is a wonderful thing.
As expected lots of goodness on Mizuno never chasing a specific number at the expense of their goals. Always love to hear Vosh break things down and Mizuno’s approach to things.
Their max has weight pulled back and is close to 10k. 9500 moi definitely isn’t nothing. They think about it but as in life all things are a balance and they’re all about that. I wish there was a way to market that which would catch people’s attention like “10k”. Just like they’re always pushing material advances but don’t have “AI” to slap on everything. Good stuff.
[QUOTE=”Jman, post: 12214668, member: 1579″]
How is that what you took from that video? He never said 9.5 was best, he explained why they don’t do 10k, that’s honesty not ma
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[QUOTE=”JB, post: 12214673, member: 3″]
I genuinely dont think that was his message or intent here.
It was that they have a number of different drivers as does everybody and chasing a MOI number isnt ideal.
For instance if someone doesnt care about offset or spinny or shaping or upright, some models may be great for them. Others may not want that, and that instead of just chasing a number, looking at it objectively through data and performance is the best recipe for success.
He certainly isnt saying 9500 is the best, as they have models as he mentioned well below that.
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I was obviously paraphrasing in my first comment but the jist was they didn’t do 10K because the looks would be affected by screwing around with COG etc etc. They came in around mid 9,000’s, while not really saying it was the best number, that’s the club they released so of course they’re going to imply mid 9,000’s is the best.
Does 10K matter? I hit the 430 10K Max very well, and hit the Qi10 like garbage. I hit my TSR2 better. No clue what MOI it is but in this highly unscientific experiment of mine, 10K does not matter.
There are knowledge bombs then there are VoshBombs. Wow, what a fantastic video and a great explanation of MOI and why just chasing a number may not be the right option!
[QUOTE=”dunkjez, post: 12214695, member: 15068″]
I was obviously paraphrasing in my first comment but the jist was they didn’t do 10K because the looks would be affected by screwing around with COG etc etc. They came in around mid 9,000’s, while not really saying it was the best number, that’s the club they released so of course they’re going to imply mid 9,000’s is the best.
Does 10K matter? I hit the 430 10K Max very well, and hit the Qi10 like garbage. I hit my TSR2 better. No clue what MOI it is but in this highly unscientific experiment of mine, 10K does not matter.
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Perhaps. Although I would argue that it is more than looks. They created a head that was 10k, but it was harder to close, needed to be offset and most likely more upright and then moved weight forward to create more speed and less pin and thus doing so came in at a number that is pretty arbitrary for the sake of performance.
Does that mean it will be best for all golfers? Of course not. Some need more spin, need more offset or like upright clubs. If the face closure is okay for them, then MOI can be their friend. The idea behind that is dont jump just because of a marketing number, jump because its beneficial for you.
[QUOTE=”dunkjez, post: 12214662, member: 15068″]
Chris explained it well but it’s still all marketing. “10K not that great, but 9.5K is the best because that’s what we’re doing.” When Mizuno does 10K, they’ll just say they figured out how to reduce spin and improve looks.
[/QUOTE]
I think if they get to 10k they’ll say it was because they found a way to add forgiveness and not to sacrifice the things they find important. That the number arrived organically through that.
I mean they could do 10k. If you were paying attention he said some of the effects of it are tough to cancel out. Not that they can’t be. Other companies aren’t going to make something people truly can’t square the face with. They sacrifice to do it. At least things Mizuno finds more important. They might have to change the face angle and hosel transition in a way they don’t want to, or end up with more spin. Even visuals and sound results come into play with everything for them.
And also if you were paying attention, when Chris mentioning making it tougher to square, he was talking about moving weight towards the [B]toe[/B], to increase the toe-heel moi.
My Gen 6 from last year is 5k, can’t imagine how forgiving 10k must be. I’d have to hit it to know though.
[QUOTE=”jlew, post: 12214445, member: 40346″]
Great video and I love how he breaks it down so that I can actually understand what he’s talking about. Thanks for doing this THP!
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That’s my thought! Chris broke it down so simply and quickly. Love this
I wonder if 10K will be like square drivers. Something that happens for a bit then goes away as there are better ways to get forgiveness other than chasing a number..
I played with 3 guys using Stealth/Stealth + in Florida and 1 playing the Qi. Although the Qi player was probably about a 15 handicap, he had far fewer missed fairways than the (presuming scratch or low cap) guy who was an excellent ball striker playing a Stealth. That being said, it didn’t seem like a magic wand.
Best driver of the ball might have been a mobility challenged 80 year old who had a Paradym driver and woods. Straight as an arrow and over 200 yards with the driver which seemed almost physically impossible for him. Had Cleveland Launcher irons that were the size of hybrids.
[QUOTE=”Templet0n, post: 12214735, member: 53139″]
I wonder if 10K will be like square drivers. Something that happens for a bit then goes away as there are better ways to get forgiveness other than chasing a number..
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I dont think so. There are ways to do it that some people simply dont care about. Slow it down, make it spinnier, have it be more upright. Face closure is the recurring theme I hear from so many going back to the PGA Show thread. Chris was the latest to touch on it here.
Build to build performance, rather than chasing a number is what I think most golfers would really want in the end. If it gets there number wise? Great. But not without the sacrifices that are currently in place for a lot of golfers.