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[frankspop]

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

[hewmanity]

Firstly, thanks for doing this. After a quick play the first thing I noticed is that you said you use a 30cm ruler and the first measurement you made and would be the case for some handles is more than 30 cm.
Second, blade length only allows input to 2 decimal points.
When I get a result, it's a number with no interpretation. Do I have to go somewhere else to work out what it means, or is it main purpose to compare to the same measure for other bats? I'll measure a couple of my bats at different extremes of weight and pick up and see what the results are.

[Buzz]

What does my reading of 0.594 mean though?

Or rather what do I do with this information?

[Kulli]

What does my reading of 0.594 mean though?

Or rather what do I do with this information?

Compare it with other (future) bats I guess.

[MichaelM]

Compare it with other (future) bats I guess.

😀😀😀

[MichaelM]

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

Forget bat mass and pickup, hmmmm

[hewmanity]

I've measured 7 bats of various weights, profiles and handle length and the correlation between dead weight and score is exceptionally strong. So it really wasn't more useful than dead weight.
I have a blank bats B1 and a kook ghost that weigh exactly the same to the gram. I find the pick up and balance of the ghost horrible and never been able to use it well in the nets as it always felt awkward. The B1 on the other hand is the total opposite. This had a 1% higher measure than the ghost, so a negligible difference.
The only interesting thing that I could get from the data was my very light small adult bat had a lower result than expected. This has a regular length blade but a super short handle.
If I can find the time I might play around with adding extra weight at various points along the same bat.

[frankspop]

Firstly, thanks for doing this. After a quick play the first thing I noticed is that you said you use a 30cm ruler and the first measurement you made and would be the case for some handles is more than 30 cm.
Second, blade length only allows input to 2 decimal points.
When I get a result, it's a number with no interpretation. Do I have to go somewhere else to work out what it means, or is it main purpose to compare to the same measure for other bats? I'll measure a couple of my bats at different extremes of weight and pick up and see what the results are.

Thanks for the feedback.
A tape measure is equally as good or a longer ruler.  I will amend the site to make that clear.
Blade length field will be changed to 3 dec places shortly. In fact all field will be set to 3 dec. places as this is appropriate.  The site was create for me by a pal, who hosts at the moment, so a small delay in any changes needed is possible

Its a good observation that there is no reference for how to use it yet, except as a comparator to your own bats, and other peoples.  Only through its wider use as a measure will you get a sense of scale and what is a value that suits your abilities.   As a comparison to bridge to the traditional measure of static mass, MOI ranges from 0.3 - 0.39 Kgm/s2, across bat weights of 2lb5oz - 2lb14oz.

[frankspop]

Forget bat mass and pickup, hmmmm

My mistake, a bit hasty while trying to write a catchy post last night.  Bat mass can still be useful, but MOI can replace the subjective 'pick-up'.  Bat mass is a useful indicator when looking at what is your optimum.  At the end of my blog article I discuss this, and the idea of effective momentum, as there is a trade-off between low MOI to generate more bat speed, but still needing sufficient mass to generate batted ball speed in the impact.  I've done some pilot work with this to show the principle.  How we help players build a swing characteristic profile is future challenge and natural evolution, but only if MOI gets a foothold in the sport.

[hewmanity]

Thanks for the range of expected values. I suspect I'm doing something wrong as all of mine are above your range. Re-reading it, I'm a little confused, am I supposed to calculate the balance  point myself? If so, wouldn't it be simpler to plug in the values on the website to avoid user error,like I may have made. Also I'm a little confused about your statement about expected range but then stating someone's value much bigger than this is too small.

[frankspop]

I've measured 7 bats of various weights, profiles and handle length and the correlation between dead weight and score is exceptionally strong. So it really wasn't more useful than dead weight.
I have a blank bats B1 and a kook ghost that weigh exactly the same to the gram. I find the pick up and balance of the ghost horrible and never been able to use it well in the nets as it always felt awkward. The B1 on the other hand is the total opposite. This had a 1% higher measure than the ghost, so a negligible difference.
The only interesting thing that I could get from the data was my very light small adult bat had a lower result than expected. This has a regular length blade but a super short handle.
If I can find the time I might play around with adding extra weight at various points along the same bat.

You are right that there is a strong connection to dead weight.  Bat mass and the location of centre of mass (balance point) are the main drivers for MOI, which is intuitive as MOI is a characteristic of the mass distribution in the bat.

I am interested in your observation of a minor change measured in MOI yet a significant difference in feel between those two bats.  That is unexpected as a 1% difference would be barely detectable (if at all), but perfectly valid if the measurements are correct, and I would be interested to know what is creating this perception.

[frankspop]

What does my reading of 0.594 mean though?

Or rather what do I do with this information?

Firstly 0.594 seems very high.  I would go back and check your input values.  Typical range is 0.30 -0.39 (which covers bat masses 2lb50z to 2lb14oz)

In terms of how to use/interpret, see my reply to a previous post.

[hewmanity]

I think I've worked out why my numbers are out, but consistently, they'd be spot on for 100cm bats.
Do handle length and blade length actually get used separately in your MOI calculations?

[frankspop]

I think I've worked out why my numbers are out, but consistently, they'd be spot on for 100cm bats.
Do handle length and blade length actually get used separately in your MOI calculations?

Yes, handle length and blade length are separate input parameters in the calculation, and each is needed.

[Cpatel93]

I think the numbers I put in are wrong

Phantom TK

31cm handle
52cm blade
0.665 kg W1
1.065 kg Total weight

The MOI = 0.453 Kg-M²

Burns TK

29.5cm handle
53.8cm balde
0.685 kg W1
1.240g Total weight

The MOI = 0.528 Kg-M<sup>2

I double-checked the weights too but no better. I think I may be weighing incorrectly</sup>