The Curious Incident of the Angle that Did Not Exceed 15 Degrees


This is the fourth in a consecutive series of posts and the reader new to the series may benefit by starting here or even the post before that.

The Squire poured another glass of Te Mata, Coleraine, enjoying the heat radiating from the walls behind him and watching the sun set over the ranks of vines that gently undulated like a graph plotting the elbow angle excursion of a legal, quick.


Third Man could sense that great mind at work which once had inspired his old friend, the Portsmouth AFC goalkeeper, and occasional bowler, Arthur Conan Doyle.  

Like any good factotum Third Man played along, bowling a long hop.  “Is there any other point to which you would wish to draw my attention?”

“To the curious incident of the angle of elbow extension.”

“The angle at no point exceeded 15 degrees.”

“That was the curious incident.”

 By this time Bob Marshall of EIT’s Department of Biomechanics had arrived.

“Bob, will you explain it to him, please.”

“It would seem that bowlers who can maintain a fixed elbow flexion during delivery can use humerus internal rotation to produce higher ball release speeds.”

“And faster rotations and a more manoeuvrable wrist,” continued  the Squire, scratching the diagram atop this post in the dust of  New Zealand’s best terroir

“The change in wrist speed is firstly a function of effective lever length, and second of the wrist distance from the internal rotation axis of the humerus.”

“Length d in the diagram.” 

“The conventional spin bowler endeavours to maximize the effective bowling arm length.”

“My modelling predicted that the generation of wrist speed due to humerus internal rotation would be greater than any loss of wrist speed due to reduction in effective bowling arm length.”

“Bob’s conclusion was that bowlers who could maintain a flexed arm through delivery either consciously or owing to an elbow abnormality either of the fixed flexion or carry angle type had the potential to achieve substantially higher wrist speeds through the use of humerus internal rotation.”

“The ICC were looking elsewhere?”

“Here’s what they need to be looking for …”  The Squire etched another diagram in the dust.


“In this elbow extension angle profile the arm flexes up to the first black line (front foot landing), stays constantly flexed up to green line (bowling arm reaches shoulder height) begins to flex slightly again as the arm moves up towards the point of release at which time the wrist is also furthest from the internal rotation axis of the humerus, only then does extension begin and continues through and beyond second black line (ball released), maximising speed of wrist rotation, or wrist flick.”

“But that’s a throw.  The same could be used to describe the technique of an Olympic javelin thrower.”

“It is possible that this effect may be utilised legally to some extent by those bowlers who flex the bowling arm slightly through ball release,” said Bob.

“But the more natural and probably most efficient method to generate ball or wrist speed is to extend at the elbow through release as in throwing,” said the Squire.

“In throwing both elbow extension and humerus internal rotation are utilised to generate ball speed.”

“So, if we took a ‘bowler’ whose elbow extension angle was around 60 or so degrees and was then extended through release, but by no more than 15 degrees, say to 48 degrees his action would have the properties of a throw despite him having an elbow extension of 12 degrees from shoulder height to ball release.”

“Yep, under the present code with its 15 degree extension limit such a delivery would be legal,” said the Squire with a catch in his throat as the sun set over the scene, casting a gloom.

“And such an action has the potential to generate higher ball speeds and more rotations than the conventional bowling action, does not have the mechanical characteristics of bowling, and uses throwing techniques.”

There is no need to bring me into this. It's a chuck.

“If it looks like a duck, swims like a duck, and quacks like a duck, then it probably is a duck.”

“Which means that every coach in the world will be teaching youngsters how to perfect it. And if a bowler can get away with an elbow extension over the 15% limit, there’s an even greater advantage to be had.”

“Maybe if a coach sat in his bath, puffing on a cigar and figuring out how best to maximize revs he’d come up with a … duck.”

“Probably he already did that.”



Filed under Uncategorized

7 responses to “The Curious Incident of the Angle that Did Not Exceed 15 Degrees

  1. growltiger

    One is bemused by the implication (which appears to be endorsed by the Squire and his frient Bob) that Muralitheran’s bowling was fine, because it was produced entirely by omega IR, and not by extension. Of course, now we understand, and are reconciled to the works of the great Sri Lankan. More to the point, the uneasy sensation (generated by watching the match in Dubai last week) that Ajmal is in some way worse, even though he doesn’t spin the ball much, is given theoretical support. Straightening the arm by a small absolute angle, over a very short period, is within the current regulations, but doesn’t have the mechanical characteristics of bowling (and doesn’t look like bowling either). Well done, the Squire.

    One can also understand the perpetual grin. It is the thrill of knowing that one has driven a coach and horses through the spirit while complying with the letter.

  2. GT
    Ferninands’ advice is that ‘a new bowling law should impose limits on the allowable elbow angle excursion slope during delivery. Such a constraint would prevent bowlers from using the same mechanisms utilised in throwing to generate ball speed – namely, humerus internal rotation and elbow extension. In light of these factors, elbow angle excursion slope is the most important determinant of bowling legality.’

    Given that the ICC will have been told this in 2003, or 2004 at the latest, why has 7 or 8 years gone by without this issue being addressed?

    Most likely they fear that too many elite bowlers would fail the Test, but as each season passes a greater proportion of elite spinners will have adopted these techniques.

    And where are the established journalists on this?

  3. diogenes

    This is fascinating. I wonder if anyone has preserved footage of all those tests they did on Harold Rhodes – his action must have been under review for about 10 years in the 60s and 70s – or Butch White?

  4. growltiger

    I think it is strange that not only the ICC but the gentry in the Sky commentary box (particularly the normally curious Atherton) seem oblivious to the actual issue. As TM says, the biodynamicists will doubtless have told the ICC of these distinctions some time since.

    I don’t believe the silence is due to a conspiracy in favour of elite bowlers, if only because Ferdinand’s data suggest that (i) most of them flex, but don’t extend, (ii) only a few extend significantly, (iii) a few benefit from internal rotation while flexing, and (iv) only the occasional “mystery” jerker rotates and extends (from a flexed starting point). TM is obviously right that, for a clever technical coach, (iv) is the way forward within the current regulations. So the Laws must be changed to prevent it.

    Regarding Harold Rhodes, the film footage did not appear to be up to much. They painted one side of his arm black, and tried to identify whether it flexed. I seem to remember it being agreed that he bowled from a hyper-extended initial state, with some flexing into the action. The opposite of what now concerns us.

  5. backwatersman

    I will have to – er – hold my hand up here and admit that I’m completely lost. I’d guess that increased tolerance of dodgy actions is largely due to a perception that the scales have become too heavily weighted in favour of the batsman (which is certainly my perception, but then I was a bowler of sorts) and that something needs to be done to make scoring runs a little more of a challenge.

    No doubt everyone’s seen this before, but – if not – here is some fascinating footage of Arthur Mold being put through his paces, bowling to Monkey Hornby in an attempt to prove that his action was legitimate –

    I don’t know what TM and his scientifically inclined masters would make of that.

  6. growltiger

    The Arthur Mold footage is indeed fascinating. It is hard to believe that this is how he bowled in the match, when being called for throwing 16 times, some of them from the bowling end (Umpire Phillips having decided to carry on calling no-balls despite Mold having been moved to Phillips’s end, after being called from square leg).

    To the naked eye, the balls delivered around 3:20, viewed from a curious camera position at short extra-cover, do not appear to be other than legitimate. The arm comes through rather low, but seems to sweep out a proper circular arc, with little visible flexing or extension. But, of course, there are not enough frames per second, and we don’t see them frozen.

    What we see in the film is at variance with the descriptions of Mold as having a notably high arm action. This is in turn hard to square with much straightening in the delivery. The suspicious factor is extreme speed and a nasty lift off the pitch, reportedly gained from a short run up (about the only commonly-reported attribute of Mold’s delivery that we do see, here). What seems certain, however, is that most judges of bowling at the time were dubious.

    Love the passing trains. Very Blofeld.

  7. John Wardle

    On Benson and Hedges video tape “Golden Greats of Cricket-Bowlers there is some interesting footage of a number of bowlers in the 50’s and 60’s. there was an attitude of tolerance in the 50’s until towards the end of the decade a number of fast bowlers with suspect actions emerged when the Establishment became more involved. A number of bowlers, such as Geoff Cope, were virtually hounded from the game. i suspect they would easily pass the scientific measures being used today.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s