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[DiscoStu]

All good points.

Firstly, your true optimum is still objectively unacheivable until a player can do a test session with a range of bat MOIs where swing performance could be measured i.e. from one of the bat sensors now on the market.  A player would need to get data on the main shots in the vertical plane (driving), and horizontal plane (cut/pull/sweep), and build a swing profile.    This is unlikely a level the masses would be interested in, but could be possible for Pros and those with the interest and money to pay for it.   Technically straightforward to do, but would be epensive at the moment.  Until that is possible then MOI knowledge complements your probable 'preferred' bat that is based on feel and performance in nets and in matches.  So that when you come to buy another, you know what to look for or specifiy if able to through custom bat makers.

MOI as you say may be marginal in terms of what it might give a customer, given all the other factors at play, but for some marginal is still valuable.

Transition to using MOI with customers is like anything new.  If we believe this is a valuable parameter to base bat selection on, it is then a matter of education/explanation to shift to a new paradigm.

I'd be happy to pop up to Leeds for a chat on this.  DM me and we can arrange something.

I think there is a use case for the data. In a similar way to how people get fitted for golf clubs, using MOI with a range of bats in a standardised setting could give a customer better advice on what to use. And from that limited range of suitable bats then make their choice based on looks, quality, price etc.

[frankspop]

I've been using POBmm from handle x MB as a measure of 'pickup' for years, but didn't know how accurate it worked out as a measure of inertia.  Your calculated MOI seems to have a more pronounced difference between weights and POB, and it's good to see some proof that it's an accurate measure of what you feel through your hands.

Interesting.  what you have been 'using for years' is called First Moment. My research (writtne up in the journal paper) showed that First Moment is a very good 'proxy' measure for MOI but requires a calibration with MOI to establish the relationship for each shape of bat. This may be practical for a bat maker, as once the relationship has been derived they only need to measure mass and location of centre of mass for each bat produced (if handle and blade lengths are kept constant). The proxy is less applicable for one-off measurements where it is best to use the two-section beam model method, which is the one used on the website.

[frankspop]

Does the website save the data? We need a scatter plot! Maybe needs to be filterable by brand as well

No, unfortunatley I am not saving the data.  That is another level of website functionality I could not ask my pal to create as it is probvably beyond his current skill level.  I agree it would be ideal to save the data and visulaise some back, but wuodl need more data enrty form the user (bat brand/model), and I might be able to do it in time if there is suffient interest to warrant me paying for it.

[hewmanity]

I reckon GM would be great brand to focus getting some data on as shapes are so consistent.
Thanks again for all your work on this!

[Chompy9760]

Your question on the equations seems to relate to the fact that through the copy/paste it is losing the division operator.  L(small2)h(big3) is Lh squared divided by 3, and same for the other one bu 12 is the denominator.

If it would help you can DM me I can send you a spreadsheet with all the equations in.  One I prepared a while ago.  I'm happy to share it to anyone who would like it.

I had no idea about the division or power operators.  I'm used to / * or ^ in everything .  My spreadsheet is now getting .264 when it should be .361, but I'm on the right track.  Will send a DM - many thanks!

[InternalTraining]

It's quite niche, and many on here already know about this. If you really want to optimise your bat selection then, materials and quality aside, forget static bat mass and 'pick-up' and use Moment of Inertia. Normally a tricky thing to measure, and one reason why it's never been adopted by bat makers.  I have now made it simple for players and bat makers alike. Have a look at my little website that shows you how, with links to a new blog for details on the what, why, and how, and a peer-reviewed journal article that explains the science.

The method is sound and validated.  It's simple and although an estimation it's accurate.  In summary the estimation uses a one-dimenional beam model approach, which has been shown to be within 1% of measured values.  The calculation tool on the website pushes your input data through a set of equations derived through the research.

https://cricketbatmoi.info

The website is newly finished. I would welcome any feedback on the user experience, any errors thrown up, or flaws in the measurement instructions.  Could be through 'Contact' on the website, or here.  And of course happy to discuss any aspect on the forum here - not least on whether MOI is seen as important enough to warrant its adoption in bat making and retail.

Thanks for reading.

David Curtis

Thank you for sharing this!

It should be standardized for all bats. I have been talking about this for a long time! Buyers will save a lot of money and time if specs like this were standardized and available with every bat.