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CW decides the greatest test spinner ever. 43 names: Countdown/Rankings thread

StephenZA

StephenZA

Hall of Fame Member
NotMcKenzie said:
I think that this is something that it often said more with the view of dismissing any argument from an easily obtainable source—match footage—than a firm basis in fact. In the case of Griffin, there is another angle on the same documentary, and it is possible with slowed footage to check the relative position of the elbow, shoulder and hand.
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I am not quite sure what you mean by this..... but 2D footage from one or 2 cameras to recreate a motion 3D motion analysis is poor. Obviously multiple camera angles is needed to give it a best chance, ideally with high quality cameras. There is a reason that hawkeye has 6 cameras, 2 of which I believe are pretty high spec on the speed (frames/s) scale, to follow and predict a path. Again I do not say that means the bowler did not throw, it is just a poor analysis.
 
NotMcKenzie

NotMcKenzie

International Debutant
StephenZA said:
I am not quite sure what you mean by this..... but 2D footage from one or 2 cameras to recreate a motion 3D motion analysis is poor. Obviously multiple camera angles is needed to give it a best chance, ideally with high quality cameras. There is a reason that hawkeye has 6 cameras, 2 of which I believe are pretty high spec on the speed (frames/s) scale, to follow and predict a path. Again I do not say that means the bowler did not throw, it is just a poor analysis.
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One does not necessarily need 3D recreation to see the change in position of one part of the arm with respect to the other, and with multiple angles, I can see that it is not caused by a change in the plane of the arm with respect to the camera. One can see how the speed and path of each of the parts of the arm varies. Maybe you can't exactly tell the angle, but it is setting an arbitrary lower limit to call it poor analysis.
 
StephenZA

StephenZA

Hall of Fame Member
NotMcKenzie said:
One does not necessarily need 3D recreation to see the change in position of one part of the arm with respect to the other, and with multiple angles, I can see that it is not caused by a change in the plane of the arm with respect to the camera. One can see how the speed and path of each of the parts of the arm varies. Maybe you can't exactly tell the angle, but it is setting an arbitrary lower limit to call it poor analysis.
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Unless the cameras have been setup up together, on similar planes or at least on known planes and differences between, the cameras have been synchronized to record so that the frame rates and images are comparable, you cannot be confident of the results. As for seeing the change of position, you cannot tell with a single camera, for example, whether the bowlers arm pulls across himself, keeps straight, maybe pushes away, or the relative twist of the body to the arm... a bowling action is a number of moving parts along many planes relative to each other and imaging from a single camera, can be very deceptive, is all I'm saying.
 
weldone

weldone

Hall of Fame Member
Howe_zat said:
It's strange that Ashwin has been placed among top players here but Anderson was clearly rejected from the fast bowling list.
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1. There are more pace bowlers than spinners.
2. Anderson's average and wpm aren't comparable to Ashwin's.
 
NotMcKenzie

NotMcKenzie

International Debutant
And all I'm saying is it is over-complication. A feature does not suddenly pop into being when imaged from multiple angles, and if the movement is in the correct plane, it will show without need for another angle. Analysis from multiple angles and deliveries merely shows that it wasn't a one-off or due to some other effect.

To return to our Griffin example, we have some other angles to go on:



Screen Shot 2018-08-31 at 6.47.47 PM.png

While we cannot say that his arm bends by x degrees, we can say that he has a curve or bend in his arm as it comes over his shoulder which is not there when he releases the ball and nor is it visible as his arm swings back down towards shoulder height if one watches the footage. Also, his forearm shows a sudden acceleration or jerk which @the big bambino mentioned.

The sophistication of an analysis does not necessarily coincide with its accuracy. Of course, you have resolution issues, but in this case, I argue that being able to slow footage from multiple angles is enough. You are approaching a sort of inverted logic that as the arm extension is picked up and even measured by a high-precision method, it is not picked up even 'qualitatively' by the lower precision ones previously available; you will tell me that that's not what you're thinking is, but IMO it seems to be tending in that direction.
 
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