Apologies from the outset for the length of this positing. It is the third in a series in which a further is planned. New readers may wish to start two posts back in time 😉
Reacting to Saeed Ajmal’s performance in the first Test of the present Pakinstan v England series, other bloggers and established journalists have made the point that to perform as expertly as Ajmal did, even throwing the ball, takes a huge amount of skill and is fascinating to watch.
It may be that Ajmal was bowling within both the laws and the spirit of the laws of cricket – the Squire and Third Man journeyed yesterday to New Zealand to find out – but one thing is for sure, if such a technique is allowed very soon every bowler will adopt it just like round-arm, once it was legalized in 1835, replaced underarm and over-arm, once it was legalized in 1864, replaced round arm (until revived by the excellent S.L. Malinga).
Why? Because throwing makes it easier to impart faster revolutions on the ball.
Can we calculate what these extra revolutions/minute are worth to a spinner?
In the summer of 2010 Third Man featured the contest between left-arm spinners Johnny Wardle and Tony Lock. Johnny’s son, John provided the following statistics by way of a comment to the post that can be found here.
Lock’s Test average pre 1959, that is before he changed his action, was 14.70 for Tests in England and 19.66 overall. For the period after 1959, following the change, it was 48.06 in England and 34.58 overall.
John also reminded readers that Alan Hill had described Lock as having “three phases” to his first class career. Pre-1952 he averaged 22.95. Between 1952 and 1957 when his action was described at best as “suspect” (Laker thought it embarrassing) his average was 14.78 and post 1958/9 when he was forced to change his action the average returned to around that of the pre- 1952 level: 23.19.
And Lock did not use the advantage to deceive in terms of direction of turn.
So, what is going on with the likes of Botha (above), Ajmal and the plethora of bent elbow ‘bowlers’ that are bestriding Test cricket, first class cricket and now, inevitably, cropping up all over the public parks and club grounds around the world?
First, some are exceeding the 15 degrees of leniency for elbow angle extension provided by the ICC code. They may do so every ball, or for certain balls, relying of the fact that there is, as yet, no ‘in-play’ means of measuring this angle or the change in this angle during the delivery.
But some appear to ‘jerk’ even when their elbow angle extensions are at or below 15 degrees (see Growl Tiger’s comment to yesterday’s post).
This phenomenon was observed by Rene Ferdinands and Ure Kersting in their research, Elbow Angle Extension and implications for the legality of the bowling action in Cricket in A. McIntosh (Ed.), Proceedings of Australasian Biomechanics Conference 5 (December 9-10), 2004, University of New South Wales, Sydney.
They noted that the ‘throwing group could not be differentiated from the other bowling groups by elbow extension angle.’
Ferdinands wrote, “This suggests that either (i) the bowlers in the throwing group were not generally throwing and the visual effect of jerkiness was an illusion, or that (ii) a throwing-type action is not solely determined by elbow extension angle. If the latter was correct, then another biomechanical concept is needed to differentiate a throw from a bowl.”
The 1947 code (4th Edition, 1970): Law 26b, with its elbow extension constraint and its time constraint, ‘just prior to release’ requires the calculation of another measurement; that of the linear rate of change of elbow angle through release, or ‘elbow excursion angle slope’.
If the elbow extends through release, as in a throw, the rate of change of elbow angle would be positive – described as having a ‘positive slope’. Conversely, if the elbow flexes through release, the rate of change of elbow angle is negative, and has a ‘negative slope’. If the bowling arm remains perfectly rigid through release the slope is zero.
In terms of the 1970 definition a legal delivery is one that has an elbow angle slope of less than or equal to 0º/s.
Ferdinands believed that this 1970 wording of the Law on throwing was preferable to the later 2000 code Law 24.3 because ‘after an initial period of elbow straightening, many bowlers are able to maintain the elbow angle or slightly flex the elbow through ball release’.
Yet notwithstanding this, in practice (i.e. from in the sample of 69 bowlers in the sample) a significant percentages of bowlers were unable to comply with this.
According to the 1970 definition 20.0% of the fast bowlers, 25.0% of the fast-medium bowlers, 27.3% of the medium bowlers, 64.3% of the slow bowlers and 20.0% of the spin bowlers would have had to be defined as throwers.
The authorities might have concluded, ‘so be it’ and forced between one in four and one in five of the sample to change their action.
But as was shown yesterday for the angle of extension it was decided that rather than ask bowlers to change their actions the interpretation of the law should be changed to an extent that brought these bowlers who were ‘assumed’ to be ‘bowling conventionally’ into legitimacy.
Ferdinands emphasised this determination or necessity to provide a license for bowlers with positive slopes by writing that ‘This would be particularly true of the faster bowling groups and the spin bowling group because these included the largest proportion of elite subjects.’
Here again an atypical group (atypical because many of them had been selected because of their ability to take wickets against first class batsman on class wickets by speed through the air, by speed of rotations and by ability to conceal the direction of rotations) was considered the norm and which therefore skewed the mean and standard deviations before then setting limits which included as many of such (first class) performers as possible as legitimate ‘bowlers’.
However, Ferdinands did conclude that, ‘Unlike elbow extension angle, elbow angle slope through release was able to differentiate those bowlers in the throwing group from the other bowling groups’, yet argued that ‘by the increasing the threshold of allowable elbow angle slope, this property could be used to further differentiate between the throwing group and the bowlers’.
He gave as an example a 150 degree positive slope as defining 65% of the throwing group as ‘throwers’.
The diagram above illustrates the ‘problem’ for administrators trying to outlaw those assumed to be throwers from those ‘assumed to be legitimate bowlers (because they were at work in first class cricket and considered OK).
If the zero or negative degree definition is selected it ‘catches’ all the throwers bar one, but also ‘catches’ the 20-25% of fast, fast medium and spin bowlers.
Does cricket really want them bowling that way? Could they with some work and help redesign their actions? Should cricket return to Law 26b of the 1970 code? By setting the elbow angle slope at negative 150-200 degrees is cricket making it even harder to police the law and inviting further slippage?
Tomorrow Third Man and the Squire will be back on The Case of the Elbow that Did Not Straighten and The One that Straightens Later, and looking at how throwing makes it easier to impart more revolutions on a ball.
They will also be casting an eye over that “teesra” delivery carefully constructed, perfected and perhaps not quite innovated by Ajmal. A lot of unscientific speculation has already been aired on this by former batsmen. What is it really all about and how would it measure up in the lab? Clue: it cleverly exploits a biomechanical potential.