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Equipment => Bats => Topic started by: Joe on June 06, 2012, 08:28:41 PM

Title: Concaving and Edge Size
Post by: Joe on June 06, 2012, 08:28:41 PM
Now, we all agree that bats with big edges that are concaved give a wider middle, whereas bats that have no concaving and small edges have a more concentrated middle.


But observe:

(http://img24.imageshack.us/img24/280/concaving.png) (http://imageshack.us/photo/my-images/24/concaving.png/)


This shows that by a lot of concaving both bats have the same area (and spine height), but due to the bigger edges of the concaved shape the middle is spread out more.


Surely this means that heavily concaved bats with big edges (e.g. the Ultra) are much better than unconcaved bats with small edges?


All opinions/crushing blows to my theories welcome.

Title: Re: Concaving and Edge Size
Post by: Ryan on June 06, 2012, 08:43:54 PM
I think Norbs covered this a few months ago...where did you find those diagrams joe?
Title: Re: Concaving and Edge Size
Post by: Watsontotty on June 06, 2012, 08:44:29 PM
Joe im not sure i agree with your theory and it can depend on a lot of other things like pressing etc etc, ive not found heavily concaved bats to be better than bats with less concaving.
Title: Re: Concaving and Edge Size
Post by: Richard @ CricTech on June 06, 2012, 08:55:16 PM
Hi Joe,

It's a very interesting point. Lets say for arguments sake that more wood = better. Hit bang out of the middle both these bats would be equally good. I think the red shading showing middle intensity is a bit misleading. If you hit the ball half way from dead center to the edge then the non-concaved bat would give you a greater density of wood, and here's the thing, people do.

This is an overlay of 14 different batsmen's impact results for the front foot drive.

(https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc6/198330_427978927235109_178138555552482_1329668_715822482_n.jpg)

and this is the backfoot

(https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc7/421377_427979583901710_1440734370_n.jpg)

you can see there's a trend to hit towards the outside edge on the front foot and the inside edge on the backfoot. This animation of the two may be a bit clearer.

https://www.facebook.com/photo.php?v=10151172970874816&set=vb.178138555552482&type=2 (https://www.facebook.com/photo.php?v=10151172970874816&set=vb.178138555552482&type=2)

You've also got to consider that the bigger the edge, the bigger the chance that you will nick off but psychologically those big edges do make you feel like you have a huge bat in your hand, even if it is only 2.8


Title: Re: Concaving and Edge Size
Post by: tim2000s on June 06, 2012, 08:58:45 PM
What your middle intensity diagrams fail to show is the depth of the middle across the face of the bat. While both bats would have a central peak that is identical (assuming that you have identical spine heights), as the middle moves away from this point you'll find that the middle intensity drops more quickly on the concaved bat. The result is that you'll actually end up with more edge than middle...

(http://www.safbats.co.uk/BAT-BLOG/wp-content/uploads/2012/02/Bat_edges2.jpg)

(http://www.safbats.co.uk/BAT-BLOG/wp-content/uploads/2012/02/Bat_edges11.jpg)

Please see this from Andy: http://www.whichcricketbat.com/cricket-bat/cricket-bats-edges-concaving-myths-smoke-and-mirrors
Title: Re: Concaving and Edge Size
Post by: Ryan on June 06, 2012, 09:01:57 PM
Cheers Tim, that's what I was getting at. A good read from Norbs!
Title: Re: Concaving and Edge Size
Post by: Joe on June 06, 2012, 09:04:19 PM
I think Norbs covered this a few months ago...where did you find those diagrams joe?
I made the diagrams myself - Tim, I see your point but if the accepted thing is that bigger edged bats spread the middle out more thewn surely they are better?
Title: Re: Concaving and Edge Size
Post by: GarrettJ on June 06, 2012, 09:05:40 PM
what about a concaved bat with a thin edge ........ like the old MH Distinction ... mine just seemed to be one big middle no matter where i hit the ball (apart from the toe) partly due to the massive spine running all the way down it.

edge was a thick as a 1p coin, spine like nothing i have seen before, covered more than two stumps when taking guard
Title: Re: Concaving and Edge Size
Post by: Ryan on June 06, 2012, 09:06:44 PM
Maybe due to the pressing?
Title: Re: Concaving and Edge Size
Post by: GarrettJ on June 06, 2012, 09:08:11 PM
Maybe due to the pressing?

fletcher that bat you sent me is feeling really good, will possibly be taking it out to battle on sunday .... weather permitting and if i can get a few nets in before to be sure it is up to facing a new ball
Title: Re: Concaving and Edge Size
Post by: Ryan on June 06, 2012, 09:09:23 PM
Cheers mate, it did knock up nice that one...hope it serves you well!  :D
Title: Re: Concaving and Edge Size
Post by: tim2000s on June 06, 2012, 09:09:33 PM
what about a concaved bat with a thin edge ........ like the old MH Distinction ... mine just seemed to be one big middle no matter where i hit the ball (apart from the toe) partly due to the massive spine running all the way down it
But that's because you are using a lot of wood and have a lot of wood throughout the length of the bat...

I made the diagrams myself - Tim, I see your point but if the accepted thing is that bigger edged bats spread the middle out more thewn surely they are better?

It depends on whether you hit the middle regularly. If you use a bat with concaving you have a less intense middle distributed more widely. As he says in his blog, you are supposed to be hitting the middle. What you are missing is that when you spread out the middle you reduce the amount of willow behind it and therefore the force that you can transfer to the ball is reduced, so while the middle is wider it is less powerful...
Title: Re: Concaving and Edge Size
Post by: RossViper on June 06, 2012, 09:49:17 PM
I think its all rubbish.... bat shape effects the feel/balance/look of the bat, not really if the middle is good, if you want a bigger middle you need a wider bat - wood and pressing begin equal, the "middle" is more to do with centre and nodes of percussion. - if what Norbs was saying was correct then every the GN Scoop would be a plank - there not are they? ;-) 

Just my 10 cents, don't want to step on anyone's toes!





Title: Re: Concaving and Edge Size
Post by: tim2000s on June 06, 2012, 10:04:53 PM
No they aren't but I don't think they feel like a bat with a spine to use...
Title: Re: Concaving and Edge Size
Post by: Joe on June 07, 2012, 06:17:18 AM
But that's because you are using a lot of wood and have a lot of wood throughout the length of the bat...

It depends on whether you hit the middle regularly. If you use a bat with concaving you have a less intense middle distributed more widely. As he says in his blog, you are supposed to be hitting the middle. What you are missing is that when you spread out the middle you reduce the amount of willow behind it and therefore the force that you can transfer to the ball is reduced, so while the middle is wider it is less powerful...
But surely if the spine height is the same then the actual middle, the one middle point, is as intense?
Title: Re: Concaving and Edge Size
Post by: RossViper on June 07, 2012, 06:22:22 AM
No they aren't but I don't think they feel like a bat with a spine to use...

exactly, no wood in the "spine", but still have good middles but feel different... wood location has little to do with the middle, a lot to do with feel...
Title: Re: Concaving and Edge Size
Post by: RossViper on June 07, 2012, 06:32:01 AM
But surely if the spine height is the same then the actual middle, the one middle point, is as intense?

Middle intensity! do me a favour, we are talking about a few grams of weight difference  at most.

If I follow Andy's logic correctly, then what he is saying in that for a given surface distance, say 5cm across the centre of the bat the con-vexed shape will have more wood than a concave, thus more mass in that area, M=FA, and so  more power.  The slight issue I have with this is that the difference in actual weight at the point the ball impacts is going to be immeasurable, so mass effects will be more to do with the whole weight of the bat.... which should be the same for a like for like.
Title: Re: Concaving and Edge Size
Post by: Joe on June 07, 2012, 06:35:09 AM
Here we are.

Blue represents concaved bat, red the non-concaved bat. Red areas are where the non-concaved bat will have more power, blue is where the concaved bat will. Stripes mean they are equal.



(http://img28.imageshack.us/img28/2340/concaving2.png) (http://imageshack.us/photo/my-images/28/concaving2.png/)

Title: Re: Concaving and Edge Size
Post by: mad_abt_cricket on June 07, 2012, 07:05:49 AM
My view:

Concaved Bat Shape:

1. Suitable for smaller grounds as you don't need to have a strong middle to clear the fence and your mishits ( away from the middle) might also give you some boundaries.

2. Suitable for those who like to hit across the line, as that's when the chances are more that one misses the middle.

3. More forgiving as even though the middle is weaker it is wider.

Classical Bat Shape:

1. A classical bat shape is more suitable for a batsman who plays mostly in the 'V' and middles the ball most of the time. This bats will give full value to drives on the 'V" and also those who like to hit straight sixes and boundaries.

2. Less forgiving, off centered shots might not go the distance.

3. If finds the middle, it is almost guaranteed that the ball will clear the fence.
Title: Re: Concaving and Edge Size
Post by: mad_abt_cricket on June 07, 2012, 07:13:33 AM
A good example showing effectiveness of a classical bat when hitting straight :

http://www.facebook.com/photo.php?fbid=10150995973101464&set=a.10150995951956464.405471.532086463&type=3&theater

My team mate, hit 5 sixes in two overs, all straight and they went over 80 meters.
Title: Re: Concaving and Edge Size
Post by: tim2000s on June 07, 2012, 07:29:43 AM
Middle intensity! do me a favour, we are talking about a few grams of weight difference  at most.

If I follow Andy's logic correctly, then what he is saying in that for a given surface distance, say 5cm across the centre of the bat the con-vexed shape will have more wood than a concave, thus more mass in that area, M=FA, and so  more power.  The slight issue I have with this is that the difference in actual weight at the point the ball impacts is going to be immeasurable, so mass effects will be more to do with the whole weight of the bat.... which should be the same for a like for like.

i think the issue that we all make with this disucssion is one alluded to by Andy in his many blogs. We look at a bat as a static object and the graphs I posted earlier are doing something similar. As a static object, F=MA varies across the face of the bat according to those graphs if the bat is static and a ball is bounced against it.

What we forget is that a bat is almost never used as a static object and is nearly always part of a dynamic system. When we play a defensive shot, generally, the ball doesn't go very far, regardless of the bat. That's the impact of concaved versus non-concaved.

When we drive, cut, pull, etc, we are using the bat dynamically. At this point the static distribution of weight across the face plays much less of a part, hence why perimiter weighting can work as it is the "swing weight" or Moment of Inertia that is in play.

In baseball, and a lot less in cricket, there have been many studies of the effects of MoI and essentially it boils down to more mass hits the ball further but a lower MoI increases the bat speed and can also allow more control of the bat.

How does this help with the discussion we are having though? Well it is my belief that one of the reasons that it's hard (but not impossible) to hit the ball a long way using the edges of the bat is that when you hit the edge, the bat twists. Back to this dynamic model again. Coming back to Ross's argument, the mass difference is minimal between thick and thin edges, so that while you may counter the twisting force with thicker edges, you don't counter it enough to make a difference.

Ultimately, the model you need to use it much more complicated than we like to pretend and a combination of forces and pivots come into play. I suspect that if you had a flat block weighing some 2lb 9oz on the end of a long stick, you'd have something that would hit the ball a long way. And I've just described a mongoose, which, let's face it, doesn't really need that minimal spine on the MMi3. It's also very similar to the shape of some of the older Duncan Fearneleys...

If we look at a baseball bat, the only way to really hit the ball far is to hit it out of the meat, which is obviously positioned, and to time it to hit it along the centre or almost the centre of the tube shape, otherwise the ball goes either up or down (usually pretty hard) due to the cylindrical shape.

For a cricket bat, it's a very similar principal with a different shape bat. Ultimately the position of the mass from the handle pivot is far more important than the position across the face as, believe it or not, even at an amateur level you hit the middle a lot more than you think... And middling it and it feeling great brings us on to the centre of percussion and vibration, which is an entirely relevant and interlinked part of the discussion which is all twisted into the position of the middle and the feel of "middling" a ball...
Title: Re: Concaving and Edge Size
Post by: RossViper on June 07, 2012, 09:31:55 AM
Cant see the picture joe, might be an issue my end....
Title: Re: Concaving and Edge Size
Post by: RossViper on June 07, 2012, 10:13:59 AM
As I've got some time let me try and tackle some of this... agian, my 10 cents... not laying down the law! ;-)

Quote
"i think the issue that we all make with this disucssion is one alluded to by Andy in his many blogs. We look at a bat as a static object and the graphs I posted earlier are doing something similar."
Nope, that's Andy confusing stuff (maybe :-)). The bat is a static object, it does not change its shape etc when you swing it. Regardless, we are talking about bat shape - or really mass distribution.

Andy's right, and its true that the system is dynamic and mass distribution etc can effect all of this, swing weight etc, but that's not what we are talking about here, we are talking about the mass distribution as an absolute driver of middle performance - any dynamic difference would need to be removed - i.e. balanced out so that can be disregarded, and we just look at the shape impact.

Quote
"As a static object, F=MA varies across the face of the bat according to those graphs if the bat is static and a ball is bounced against it."
Well it really just depends how you measure it, normally you will be looking at the centre of mass, which is one point of the bat surface, so no, it does not really change across the face of the bat.

Quote
"What we forget is that a bat is almost never used as a static object and is nearly always part of a dynamic system. When we play a defensive shot, generally, the ball doesn't go very far, regardless of the bat. That's the impact of concaved versus non-concaved."
True, but irrelevant to decision on bat shape I think... to test the effect of the bat shape, we could just keep the bat still and fire the ball in to the different parts, that would isolate the effect of bat shape.

Quote
"When we drive, cut, pull, etc, we are using the bat dynamically. At this point the static distribution of weight across the face plays much less of a part, hence why perimiter weighting can work as it is the "swing weight" or Moment of Inertia that is in play. "
Again true, but its a different thing, if the shape can allow you to swing the bat faster, then great, but we are talking about absolute middle performance as an effect of mass distribution, everything else must be ignored.

Quote
"In baseball, and a lot less in cricket, there have been many studies of the effects of MoI and essentially it boils down to more mass hits the ball further but a lower MoI increases the bat speed and can also allow more control of the bat."
Yes, that's just basic physics. 

Quote
"Well it is my belief that one of the reasons that it's hard (but not impossible) to hit the ball a long way using the edges of the bat is that when you hit the edge, the bat twists. Back to this dynamic model again. Coming back to Ross's argument, the mass difference is minimal between thick and thin edges, so that while you may counter the twisting force with thicker edges, you don't counter it enough to make a difference."
Again this is true, in part, but again twisting effects is another issues, it not about the absolute middle performance, and while it might be relevant over all, it should not for part of this disscsion for the same reason as above.

Quote
"Ultimately, the model you need to use it much more complicated than we like to pretend and a combination of forces and pivots come into play."
No we jut need to ask a more focused question. In fact pivots and forces are irrelevant, you have to assume they are all the same, otherwise you can't make any comparisons with anything ever!

Any way, who cares!  ;-)

Good stuff, all in the right spirit.
Title: Re: Concaving and Edge Size
Post by: tim2000s on June 07, 2012, 10:30:59 AM
Nope, that's Andy confusing stuff (maybe :-)). The bat is a static object, it does not change its shape etc when you swing it. Regardless, we are talking about bat shape - or really mass distribution.
Andy's right, and its true that the system is dynamic and mass distribution etc can effect all of this, swing weight etc, but that's not what we are talking about here, we are talking about the mass distribution as an absolute driver of middle performance - any dynamic difference would need to be removed - i.e. balanced out so that can be disregarded, and we just look at the shape impact.

So having a discussion about variation using this as a basis takes us back to Andy's graphs and where the maximum amount of willow is and how that affects the "specific performance" if you like. In looking at it in this fashion, yes it is a static item, and actually, on a perimiter weighted bat, where the torsion can be controlled, you should see a slightly better rebound at the edges, assuming uniform.

"What we forget is that a bat is almost never used as a static object and is nearly always part of a dynamic system. When we play a defensive shot, generally, the ball doesn't go very far, regardless of the bat. That's the impact of concaved versus non-concaved."

True, but irrelevant to decision on bat shape I think... to test the effect of the bat shape, we could just keep the bat still and fire the ball in to the different parts, that would isolate the effect of bat shape.

No we jut need to ask a more focused question. In fact pivots and forces are irrelevant, you have to assume they are all the same, otherwise you can't make any comparisons with anything ever!

Any way, who cares!  ;-)

Good stuff, all in the right spirit.
Disagree with you, otherwise why bother with the Scoop... And square cm for square cm, the Scoop has less rebound than, say, the distinction in the centre of the bat. It's to be expected. How much less? It isn't relevant due to the pivots and forces involved ;)
Title: Re: Concaving and Edge Size
Post by: 100 not out on June 07, 2012, 11:36:47 AM
All im saying is no concaving. the best bats ive had have been this type of profile.
Title: Re: Concaving and Edge Size
Post by: trypewriter on June 07, 2012, 12:29:10 PM
I think concaving or not, spine or not, there are a lot of variables to consider. First off, you are playing a moving ball, which could be swinging in, away, or dead straight (never mind actually spinning) in the lateral plane. Then it could be doing the same things in the vertical plane - cos we do get uneven bounce etc. Add to this, in a very simplistic way, the batsman's natural swing - is it inside out, outside in, or invariably straight? (We'd all like to think the latter I'm sure). And I'm only talking drives here, not cuts, pulls and the like (where a roll of the wrists can come into play). Golfers tend to obsess about their swings, and rightly so, because for the majority the basic aim is to hit the ball straight with admirable consistency. And remember, this is a static ball, so in theory (and golfing mates will love you for this tongue in cheek suggestion) how hard can it be to achieve that, as opposed to dealing with a moving ball hurled down with evil intent?
Fascinating debate though.
Title: Re: Concaving and Edge Size
Post by: Bez013 on June 07, 2012, 06:45:13 PM
Being entirely unscientific (I'll just end up looking like a tit if I try and engage in that) and basing my theories on bats I have used or seen being used I actually think all of the different bat shapes make less difference than we all might expect, be it a Scoop, Dynadrive, Concave, Convex or Brick on a Stick.

I'm in no position to show that the models used are incorrect but as has been aluded to already based on the diagrams used a Scoop should be terrble as those models reflect that the 'middle' is behind the point of the spine and would get worse as the bat gets thinner towards the edges.  Anyone watching Sky Sports on Sunday will have seen Phil Mustard score 100 off about 70 balls for Durham and for 98 of those runs he was using a GN Scoop.

The biggest 6 I've ever hit, by some distance, was with a fairly light Slazenger V500 of c.late 90s vintage with no concaving and not much in the way of edges, it didn't exactly have a huge spine either. 

I also used a GN Phoenix for a number of years which has two fair sized cutouts in the back a bit like a Dynadrive and had an absolutely stonking 'middle' despite the lack of wood behind the main hitting area.
Title: Re: Concaving and Edge Size
Post by: mattw on June 07, 2012, 06:54:27 PM
I'm in no position to show that the models used are incorrect but as has been aluded to already based on the diagrams used a Scoop should be terrble as those models reflect that the 'middle' is behind the point of the spine and would get worse as the bat gets thinner towards the edges.  Anyone watching Sky Sports on Sunday will have seen Phil Mustard score 100 off about 70 balls for Durham and for 98 of those runs he was using a GN Scoop.

Sorry, but he only scored about 20runs with it and then he change back to his normal oblivion as it wasn't going too well...
Title: Re: Concaving and Edge Size
Post by: Bez013 on June 07, 2012, 07:42:14 PM
If you are correct then my apologies, but I am certain he swapped the bat when when Stoneman was out as the grip had come loose on the Scoop, I found it amusing at the time as Mustard got only a few balls later.
Title: Re: Concaving and Edge Size
Post by: norbs on June 14, 2012, 10:27:30 AM
Not sure where you all got to on this one, but that is exactly why I wrote that blog.  Some [most] of the blogs are dumbed down a bit and it is for that reason why F=ma is in this one. At school we all learn about Netwons 3 laws of motion the one's we remember are Netwons 2nd law and 3rd Law.

For example if I wrote for 2nd law, "The rate of change of momentum is proportional to the imposed force and goes in the direction of the force."

F=ma is easier for us to remember

It works the other way round for the 3rd Law - For every action there is an equal and opposite reaction, is what remember

If I started putting in equations and calculations for this it would involve a whole raft of stuff that is relevant to cricket bat performance and there profiles, MOI, torsion stiffness, Fibre fraction, vibration etc etc I'd lose people and they'd would switch off

So to get everyone thinking about bats, there shapes and there profiles.  It is wirtten that way and looks like it works.

Let use another example, I get loads of bats to look at when I'm at the club, loads of varying shapes, sizes etc all proudly handed across to me for an opinion.  1st thing I was always say is do you like it?  That is the most important thing, I hate it when I hear people picking up a bat saying that is small edge bet it is rubbish.  I always make a point of going over and tapping take a look ask the weight and explain bits and pieces and again ask them if they like it.

If you look at the blogs they are all related to eachother to give you an overall idea of why bats perform, it isnt just one blog that defines everything about bats it is all to do with the bigger picture


Great thread and from what I read it is a good discussion, BTW scoops are the exception and a different subject really
Title: Re: Concaving and Edge Size
Post by: trypewriter on June 14, 2012, 10:45:59 AM
1st thing I was always say is do you like it?

Spot on!
Title: Re: Concaving and Edge Size
Post by: Chad on August 14, 2012, 01:08:29 AM
I personally am finding myself to prefer bats with very little to no concaving now. I recently started using a Newbery Mjolnir, and it has a big long middle with very thin edges and a traditional non concaved profile. The first thing my friend says is that I made a mistake and should have gotten a GT instead, as it has bigger edges and looks better. A week later, we were doing throw downs to play in the bat, and after trying the Newbery, he completely changed his opinion on it. Pretty much only one other bat I have used to date feels nicer driving off the front foot.

Ironically, despite me preferring bats with no concaving, that other bat is my Black Cat Custom made to the shape of a 2010 Distinction. The concaving is done though so that the edges are smaller than anything in the middle of the bat, and it is quite a steep concave in order to make the spine as big as possible to reward near enough any shot out of the middle. The spine height is really quite impressive even near the stickers. Despite being a student, I don't really like looking at the science side of things, and quite like to go for test runs and then base my opinion on that. Generally speaking though, I don't really like bats which have edges bigger than some parts of the middle, as it isn't the area where you are meant to hit the ball, and if there is any concaving, it has to be either very slight, or perform as well as my BC. 8)
Title: Re: Concaving and Edge Size
Post by: mally777 on August 19, 2012, 08:00:00 PM
Is there any difference in the durability of heavily concaved bats? Are they more likely to crack in the most concaved area due to the relative thin-ness of wood there? Am thinking of getting a concave shape bat but wasnt sure if they are more likely to crack?
Title: Re: Concaving and Edge Size
Post by: norbs on August 21, 2012, 09:07:33 AM
none that I know of