The Doosra … and the ridiculous 15° rule.
The accepted technique of bowling a doosra.
The bowler delivers the ball with the same finger action as a normal off break, but cocks the wrist so the back of the hand faces towards the batsman. This gives the ball spin in the opposite direction to an off break, causing it to spin from the leg side to the off side to a right-handed batsman.
The biomechanics at the elbow joint.
With the upper limb held horizontal, if the forearm is rotated to make the palm face the ceiling, the movement at the elbow is called supination. This is the action of an off-break bowler.
The opposite movement of turning the forearm to make the hand face the floor is pronation. The action of the leg-break bowler.
There are two muscles that causes supination; the supinator and the biceps.
1) The supinator is smaller and the weaker of the two muscles. And it can only function with the elbow dead straight.
2) The biceps we know is a big muscle and hence stronger. It bend (flexes) the elbow from its straight position. It also causes supination, but only when the elbow is bent and not when it is dead straight.
For an off-break bowler, bowling overarm with a legal straight elbow, will be using the supinator muscle to generate spin and will not be able to utilise the biceps.
But to bowl a successful doosra, the back of the hand has to face the bowler. In this position the elbow is already in full supination and the supinator is unable to function. To generate any spin, i.e. further supination the biceps has to be brought in to assist in the movement. In other words the elbow has to be flexed to achieve the ‘spin’ for the doosra.
I do not know how a bowler, while running upto the point of his deliver, can rotate his shoulder in an overarm action holding his elbow fully straight and forearm in full supination. I have tried, its almost impossible.
To deliver a spin to achieve the doosra with an overarm action and a dead straight elbow, the body has to lean towards the bowling-arm side and do a semi-hemi-demi pirouette like a hesitant ballet dancer.
It is far easier to achieve the doosra with a roundarm action with the elbow slightly bent. This gives the opportunity to straighten the elbow when delivering the ball.
The definition of ‘throwing / chucking’.
In throwing the power is transferred to the object by straightening a bent (flexed) elbow. That power generated in this way is fairly strong is seen in baseball, where the pitcher can deliver the ball with high velocities from almost a stand-still posture.
It can be concluded that in the sequence of movements of the elbow, the final action is one of straightening (extension) by the biceps, which also delivers a spin by further supination. This action generates the power necessary for the bowler to be able to pitch the ball at a correct length and enough spin to beat the batsman.
Without this final movement it would be a weak delivery with hardly any spin; and an added task for the ball-boys to retrieve the ball from the stadium roofs.
Professor Bruce Elliott who conducted biomechanical tests on Muralitharan, could demonstrate 10 deg straightening of the elbow just before the point of delivery. I do not know by how many degrees the other doosra bowlers bend their elbows. Murali’s Doosra explained.
(I would like to state that I could only find the figures of Muralitharan’s test in my search on the net.)
We are aware of the tests that he has done on other bowlers and found varying degree of bending at elbows, prompting him to call for a greater latitude for all bowlers.
Doosra ban prompts call for greater latitude for bowlers
I wonder if we are making issues like this more controversial and more complicated by employing high-tech? There was a time when a ‘chucked delivery’ was called a no ball by an umpire based on his visual assessment.
And it is well with the capabilities of a human being to assess the movement with naked eyes, as seen in this animated clip from The Mechanics of Off-Spin – Russell Degnan.
I accept there will always be umpires who are biased or indeed racists who will try to target and victimise bowlers. But that is easier to control by stricter rules on code of conducts of the umpires. If biomechanics is being used to clear a bowler, it should also be used to question the credibility of the umpire whose call cast unnecessary doubts on a bowler’s action.
I believe these high-tech biomechanical tests have given rise to more questions than answers.
My main question is:
1. Is it possible at all to bowl a perfectly legal doosra?
The other questions are
2. is a flex and extend always a throwing action?
3. should we be changing the rules or sticking to the original; of the umpires having the discretion to call a ‘throw’ a no-ball.
4. if it really was calls by some biased umpires that initiated the controversy, by focussing only on the degrees and minutes and seconds of an angle are we not failing to correct the real problem?
Finally, it is argued the rules do not apply to players who have some form of defects from births, ie hyperextensions and fixed flexions.
5. should we relax the rules to accommodate players who gains an advantage because of their deformities or be strict in implementing them. If a player claims he should be able to bowl underarm as he has defective shoulder joint or muscles, should he be allowed?
To have an any° rule is ridiculous.
I argue that there be no limit to how much an elbow bends before delivery – make the playing field truly level for all.
This is an article written as a discussion of the technique of bowling doosras.
This is not a criticism or assessing bowling action of any bowlers practising this skill in the game at present.