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[RossViper]

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...

[RossViper]

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.

[Joe]

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.

[mad_abt_cricket]

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.

[mad_abt_cricket]

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.

[tim2000s]

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...

[RossViper]

Cant see the picture joe, might be an issue my end....

[RossViper]

As I've got some time let me try and tackle some of this... agian, my 10 cents... not laying down the law! ;-)

"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.

"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.

"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.

"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.

"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. 

"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.

"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.

[tim2000s]

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

[100 not out]

All im saying is no concaving. the best bats ive had have been this type of profile.

[trypewriter]

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.

[Bez013]

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.

[mattw]

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...

[Bez013]

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.

[norbs]

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