Wrist Spin Bowling (part Five)

[leftie600]

I think it's all abundantly clear. Spin creates a vacuum-like effect that changes the normal flight of a ball. Seam position also effects the normal flight of a ball. Therefore, a cleanly presented seam when bowling (whether bowling spin or seam) will aid movement through the air. Of course, you are then presented with other problems if the batter is watching the seam position and batting accordingly. You may well chose, in that instance, to scramble the seam. But fundamentally, if you want to move the ball in the air, bowl with a clean seam.

I'm not saying you're wrong but I haven't seen or read any scientific proof that bowling with a non-scrambled seam is better for the magnus effect than a scrambled seam. If you produce a link to something that would be cool.

 

[boogiespinner]

you can beat some batsmen off the pitch, but the really good bats have a better read of it and to beat them, it's more likely going to be done through the air.

Some batsman may indeed be good readers, but it's a very strong statement to say that a good batsman will ALWAYS judge the amount a ball is going to turn, you can't deceive him with a googly, you can't deceive him with a slider, you can't deceive him with a bigger leg break, you can't deceive him with natural pitch variation or scrambled seam... even conceding him the advantage of judging correctly where the ball will pitch.

My main bugbear here is not the truth of that but that we should speak for ourselves! It's not fair to put words in the mouth of his holiness the almighty Warne.

 

[someblokecalleddave]

I'm not saying you're wrong but I haven't seen or read any scientific proof that bowling with a non-scrambled seam is better for the magnus effect than a scrambled seam. If you produce a link to something that would be cool.

When I was trying to get my head round all this stuff, I found that there was very little research backed up with video evidence that you can lay your hand on with regards the spinning ball and spin bowling. There's some stuff that looks into the effect of the up-right seam, mostly it's all about the rough and smooth side affect in seam bowling. Brian Wilkins book might be the answer, but I've got an art brain rather than a maths/physics brain and I can't get my head round it, I need to see slow motion high speed video footage and I cannot believe no-ones ever done it yet!!!!! The frustrating thing is, I've got contacts that mean I might be able to get access to the high speed cameras for free, but what's the point if I get the camera and no-one that can turn up on the day and bowl all the variations with drift so that they can be recorded and at last I might be able to make sense of it all! Wouldn't that be good though, how many hits would that get me on Youtube!!!!

 

[leftie600]

When I was trying to get my head round all this stuff, I found that there was very little research backed up with video evidence that you can lay your hand on with regards the spinning ball and spin bowling. There's some stuff that looks into the effect of the up-right seam, mostly it's all about the rough and smooth side affect in seam bowling. Brian Wilkins book might be the answer, but I've got an art brain rather than a maths/physics brain and I can't get my head round it, I need to see slow motion high speed video footage and I cannot believe no-ones ever done it yet!!!!! The frustrating thing is, I've got contacts that mean I might be able to get access to the high speed cameras for free, but what's the point if I get the camera and no-one that can turn up on the day and bowl all the variations with drift so that they can be recorded and at last I might be able to make sense of it all! Wouldn't that be good though, how many hits would that get me on Youtube!!!!

You'd be a YouTube god Dave.

I've read only one specific reference to it and that only gave a guess from a scientist rather than anything that was tested and proved. He stated that he thought a scrambled seam would produce a greater average rough area for the magnus effect to take hold, that was just a guess by him though. I very much doubted his reasoning so I've never linked the article.

What I have read, that was also tested, is that the rougher the surface is the greater the effect (i.e. a tennis ball has a greater potential for drift than a billiard ball).

So does having the seam in a 'perfect' position allow for a greater magnus effect or scrambling it? Anyone got access to a wind tunnel and some boffins for some quick testing?

 

[boogiespinner]

You'd be a YouTube god Dave.

I've read only one specific reference to it and that only gave a guess from a scientist rather than anything that was tested and proved. He stated that he thought a scrambled seam would produce a greater average rough area for the magnus effect to take hold, that was just a guess by him though. I very much doubted his reasoning so I've never linked the article.

What I have read, that was also tested, is that the rougher the surface is the greater the effect (i.e. a tennis ball has a greater potential for drift than a billiard ball).

So does having the seam in a 'perfect' position allow for a greater magnus effect or scrambling it? Anyone got access to a wind tunnel and some boffins for some quick testing?

It would make sense. I don't think Murali was noted for drifting the ball, and I think he scrambled the seam?

Mike Brearley concurs:

Murali... operated rather like Lance Gibbs of West Indies; both bowled with high actions, without drift from leg, and from wide on the crease, relying on bounce and spin beyond the normal.

http://www.theguardian.com/sport/blog/2010/jul/24/muttiah-muralitharan-800-test-wickets

 

[Spin Lizard]

...it's a very strong statement to say that a good batsman will ALWAYS judge the amount a ball is going to turn, you can't deceive him with a googly, you can't deceive him with a slider, you can't deceive him with a bigger leg break, you can't deceive him with natural pitch variation or scrambled seam...

nobody said that though

 

[someblokecalleddave]

It would make sense. I don't think Murali was noted for drifting the ball, and I think he scrambled the seam?

Mike Brearley concurs:
http://www.theguardian.com/sport/blog/2010/jul/24/muttiah-muralitharan-800-test-wickets

I like this, this gives me hope!

 

[Spin Lizard]

"strong statement"

nobody said that though

apologies, Cleanprophet did say that.

I don't think anyone has been 'putting words into the mouth of Warne' though, to address your main gripe. He has talked about this before.

 

[boogiespinner]

apologies, Cleanprophet did say that.

I don't think anyone has been 'putting words into the mouth of Warne' though, to address your main gripe. He has talked about this before.

I have possibly made a bit of a meal of this. I could have just said, I wonder if Warne would actually say such a thing. That would have been more skilful. I apologise for the heavy handedness.

 

[boogiespinner]

well that tells me! well spotted Chino.

Maybe I should take a break from posting :-/

 

[someblokecalleddave]

well that tells me! well spotted Chino.

Maybe I should take a break from posting :-/

No don't! Keep posting, we can't lose posters!!!

 

[Spen]

Excusing your bestest belligerent friend, the professor is talking specifically about swing and not the magnus effect (drift) and that doesn't prove or disprove any magnifying effect that a perfect spinning seam position has on drift.

Do like the point about the 3 factors that make a good spinner: drift, dip and spin. Paul Strang states that those are the 3 things he looks for in from any potential spinner.

Just dragging the topic back to this, as I am a nerd of this description, for those interested in airflow etc. also look up the Bernoulli and Venturi effect.

A scrambled seam will affect the airflow and therefore reduce swing/drift. I'm not too familiar with the Magnus effect, rotating cylinders, but by looking at basic aerodynamics on a pace bowler, if you have a non-scrambled seam then you are getting a less interrupted airflow. Lift being produced, in basic terms, by the air travelling faster over one surface than another.

This .gif demonstrates it on an airfoil http://upload.wikimedia.org/wikipedia/commons/9/99/Karman_trefftz.gif

I've just briefly read about the Magnus effect, it is getting late so I will have to re-visit what I write in the morning to check I haven't made a massive mistake but from I understand, it isn't a case of a magnifying effect, it is more a degenerative effect by not having it. If you don't have a straight seam then you are going to interrupt the airflow and scramble the boundary layers a lot more thus reducing any aerodynamic effect.

 

[leftie600]

Just dragging the topic back to this, as I am a nerd of this description, for those interested in airflow etc. also look up the Bernoulli and Venturi effect.

A scrambled seam will affect the airflow and therefore reduce swing/drift. I'm not too familiar with the Magnus effect, rotating cylinders, but by looking at basic aerodynamics on a pace bowler, if you have a non-scrambled seam then you are getting a less interrupted airflow. Lift being produced, in basic terms, by the air travelling faster over one surface than another.

This .gif demonstrates it on an airfoil http://upload.wikimedia.org/wikipedia/commons/9/99/Karman_trefftz.gif

I've just briefly read about the Magnus effect, it is getting late so I will have to re-visit what I write in the morning to check I haven't made a massive mistake but from I understand, it isn't a case of a magnifying effect, it is more a degenerative effect by not having it. If you don't have a straight seam then you are going to interrupt the airflow and scramble the boundary layers a lot more thus reducing any aerodynamic effect.

No one is disputing the necessary uninterrupted airflow up to the seam for swing (or interrupted before the seam for reverse swing).

Drift is accepted as a result solely of the magnus effect, does a scrambled seam inhibit the magnus effect for a cricket ball? (My guess is yes).

If this is true how are tennis players able to get a tennis ball to drift they way they do? A tennis ball is far rougher than a cricket ball, is it a case of a tennis ball just having far greater revs when hit?

 

[Spin Lizard]

tennis ball is a lot lighter, revs to weight ratio. plus I think the tennis ball loses shape contributes


scrambled seam should still drift, but the good seam has a relatively 'smoother' boundary layer hence more effect. thats how i understand it.

 

[Spen]

No one is disputing the necessary uninterrupted airflow up to the seam for swing (or interrupted before the seam for reverse swing).

Drift is accepted as a result solely of the magnus effect, does a scrambled seam inhibit the magnus effect for a cricket ball? (My guess is yes).

If this is true how are tennis players able to get a tennis ball to drift they way they do? A tennis ball is far rougher than a cricket ball, is it a case of a tennis ball just having far greater revs when hit?

Sorry, I wasn't disputing it I was just waffling on about one of my most interested subjects, aerodynamics etc. for swing.

I would say undoubtedly, it does inhibit it. As for a tennis ball, it is rougher but it is consistently rougher (For the most part), plus as Spin Lizard said above the weight to revs makes a massive difference to this also, in fact, I would say that is the principal factor.

scrambled seam should still drift, but the good seam has a relatively 'smoother' boundary layer hence more effect. thats how i understand it.

This is correct to my understanding.

 

[boogiespinner]

I would say undoubtedly, it does inhibit it. As for a tennis ball, it is rougher but it is consistently rougher (For the most part), plus as Spin Lizard said above the weight to revs makes a massive difference to this also, in fact, I would say that is the principal factor.

Cricket ball mass: 160g
Tennis ball mass: 57g

-> three times the drift for the tennis ball

Spin from Shane Warne: 50 rev/s
Spin from kick tennis serve: 50 rev/s source http://www.ncbi.nlm.nih.gov/pubmed/23724605

-> similar

The greater speed of a tennis serve will result in greater sideways forces but of course it will cover the ground faster. I don't know what speed maximises drift over a given distance.
-> don't know

roughness / smoothness
> don't know

Table Tennis features very high spin rates (over 100 rev/s) and a really light ball!

 

[someblokecalleddave]

Sorry, I wasn't disputing it I was just waffling on about one of my most interested subjects, aerodynamics etc. for swing.

I would say undoubtedly, it does inhibit it. As for a tennis ball, it is rougher but it is consistently rougher (For the most part), plus as Spin Lizard said above the weight to revs makes a massive difference to this also, in fact, I would say that is the principal factor.



This is correct to my understanding.

I think that's well explained, but it's important to keep in mind that it is much harder to impart spin on a tennis ball with a wrist spin action. In my personal experience a hard spun, scrambled scream leg break drifts just as much as one with a clean seam. Of course, this is based on my perception, which isn't accurate because it is difficult to track something that doesn't move in a linear direction. There could be a slight difference, but that slight difference definitely isn't enough to make up for the advantages you can get when bowling with a scrambled seam. It's harder to pick the direction of spin, the ball will have varying bounce and turn, and it could even skid on unexpectedly.

Allan Border once told Warne that he needed to vary his clean seam deliveries with scrambled seam deliveries, when every ball has a clean seam it gets easy for the batsman to pick the exact angle of spin and counter it (provided the batsman is a good player of spin) Usually I bowl my leg break with more flying saucer spin when I want to drift it extra. A scrambled seam leg break will rarely drift more than a clean some leg break, but it isn't as easy to impart great spin on the ball when holding it with your spinning finger against the smooth sides of the ball.
As far as I know, a ball with a rougher surface, less weight and flatter seam will drift more, but I think we've established this.
Something else that helps the effectiveness of drift is how flat the ball's trajectory is. If you can bowl the ball straight at the batsman's eye level and make it drift it will get you wickets (when combined with dip and turn) but the higher you flight the ball the less effective drift becomes.

I'm sorting a diagram right now - because what you're saying here Chino in my head makes sense, but I think when you see the diagram you're going to say no... Give me a little while and come back to me, hopefully Spen may be able to explain this in laymans terms? Watch this space. First illustration, but I've realised I need another.


Diagram (A).

Diagram (B).

Okay here we go. Diagram (B) is how a top-spinner works. With top-spin put on the ball, the ball follows the trajectory indicated by the red line. It starts off on what seems like a logical line indicated by the white line, but because of the over-spin, the ball dips viciously earlier than expected. Even I know this and I can execute this ball and it makes sense to me. The same logic is then reinforced by the video here.

So what I can't comprehend is that in Diagram (B) the ball is spinning as below.
The ball then dips in the direction of the arrows at the leading edge of the ball. (Direction of the green 'Dip' Arrow)...

But, this would be exactly the same illustration for Chino's flying saucer ball viewed in diagram (A) and my expectation would be that the ball would swerve to the off-side because of the same reasons the top-spinner dips? This is then reinforced by the demo at 3.15 in this video here. So I'm completely baffled by Chino's use of the flying saucer ball if we assume that it veers towards leg in total opposition of the demo in the video?

 

[Spen]

You have put me on the spot, Dave! I found this, I've read through it and it makes sense and will explain it better than I will do. It also says something that I had overlooked, I forgot the effect of gravity and in my own mind I was applying the Magnus effect to a straight velocity in theoretical land. When I studied aerodynamics it was to an airfoil sat in empty space with laminar airflow moving across it, it has also been a few years so that's why I always put '...my understanding' after everything! Haha.

http://pencilcricket.blogspot.co.uk/p/magnus-effect-in-leg-spin-bowling.html

I've picked out some quotes;

"This means the ball can be subject to a portion of the Magnus effect at any point where the axis of rotation is not directly along the line of travel. The reason most textbooks overlook this effect is that they lazily forget that the ball is not travelling in a straight line: it travels in a curved path up and down due to gravity, and hence the Magnus Effect does come into play, since the ball's axis of rotation changes relative to its direction of motion, despite remaining horizontal at all times relative to the ground."

"One thing that's important to note: Magnus effect is proportional to speed, and gravity and drag will change the ball's speed over the course of its trajectory."

"Then there's the dimensions of the ball. Firstly increasing the size of the ball will generate more force, and then the mass of the ball will reduce the amount of movement. Note that the mass doesn't affect theamount of force generated, but it will reduce the acceleration that that force produces, so less drift. There's a bit of leeway in the Laws about how large and heavy a ball can be when new, and also a ball can change size and weight as a match progresses, but I'd imagine these two factors will often tend to cancel themselves out.
The size of the seam may also have an effect, at least when the seam's spinning at an angle to the ball's motion, as this will disrupt the airflow over the ball. I seem to recall reading somewhere that leg-spin's relative decline from the 1960s onwards may have had something to do with growing seams meaning less traction off the pitch, but I'd venture to speculate (and it is pure speculation) that this growing of the seams also affected the aerodynamic properties of the ball."

 

[someblokecalleddave]

You have put me on the spot, Dave! I found this, I've read through it and it makes sense and will explain it better than I will do. It also says something that I had overlooked, I forgot the effect of gravity and in my own mind I was applying the Magnus effect to a straight velocity in theoretical land. When I studied aerodynamics it was to an airfoil sat in empty space with laminar airflow moving across it, it has also been a few years so that's why I always put '...my understanding' after everything! Haha.

http://pencilcricket.blogspot.co.uk/p/magnus-effect-in-leg-spin-bowling.html

I've picked out some quotes;

"This means the ball can be subject to a portion of the Magnus effect at any point where the axis of rotation is not directly along the line of travel. The reason most textbooks overlook this effect is that they lazily forget that the ball is not travelling in a straight line: it travels in a curved path up and down due to gravity, and hence the Magnus Effect does come into play, since the ball's axis of rotation changes relative to its direction of motion, despite remaining horizontal at all times relative to the ground."

"One thing that's important to note: Magnus effect is proportional to speed, and gravity and drag will change the ball's speed over the course of its trajectory."



"Then there's the dimensions of the ball. Firstly increasing the size of the ball will generate more force, and then the mass of the ball will reduce the amount of movement. Note that the mass doesn't affect theamount of force generated, but it will reduce the acceleration that that force produces, so less drift. There's a bit of leeway in the Laws about how large and heavy a ball can be when new, and also a ball can change size and weight as a match progresses, but I'd imagine these two factors will often tend to cancel themselves out.
The size of the seam may also have an effect, at least when the seam's spinning at an angle to the ball's motion, as this will disrupt the airflow over the ball. I seem to recall reading somewhere that leg-spin's relative decline from the 1960s onwards may have had something to do with growing seams meaning less traction off the pitch, but I'd venture to speculate (and it is pure speculation) that this growing of the seams also affected the aerodynamic properties of the ball."

Spen - one bit at time please, as I really struggle with this stuff. So, the dipping action with the top spinner is the magnus effect...

So this illustration here is for a back spinner so the ball would hold a straighter line and not dip like top spinner and remain straighter through the air as a Flipper and an Orthodox back-spinner. That I can grasp and that I can see happening and when I bowl. So that takes care of those kind of deliveries. Chino has now thrown a spanner into the mix by introducing a ball that spins through the air like a flying saucer. So for me with the ball spinning in that fashion, gravity aside, the ball should swerve side ways in the way the old bloke gets the ball to do in the video. Kind of... magnus effect turned on its side? Is that right in essence?

Like this...

 

[leftie600]

Spen - one bit at time please, as I really struggle with this stuff. So, the dipping action with the top spinner is the magnus effect...

So this illustration here is for a back spinner so the ball would hold a straighter line and not dip like top spinner and remain straighter through the air as a Flipper and an Orthodox back-spinner. That I can grasp and that I can see happening and when I bowl. So that takes care of those kind of deliveries. Chino has now thrown a spanner into the mix by introducing a ball that spins through the air like a flying saucer. So for me with the ball spinning in that fashion, gravity aside, the ball should swerve side ways in the way the old bloke gets the ball to do in the video. Kind of... magnus effect turned on its side? Is that right in essence?

Yes.