Selecting a fourth bowler
Russell Degnan

Stuart MacGill's supporters are a disbelieving lot. Not only can't they believe he isn't playing, they can't believe the selectors might have good reasons for it. Personally, I approve; MacGill isn't accurate enough; goes for too many runs, and is a one-dimensional cricketer with nothing to offer if he isn't getting wickets.

It is often said that this draws unfair comparisons with Warne, and that leg-spinners shouldn't be expected to bowl with such unerring accuracy. It is precisely for this reason that leg-spinners were on the way out -- expect for a few one-off tests -- until Warne revived the art a decade ago. An innacurate and expensive bowler is a liability. But just how big a liability is worth considering.

There are two aspects to this. The first is to consider the affect on the "team" bowling performance. Whether it better to keep things tight and force the batsmen to play bad shots, or to bowl a heady mixture of unplayable deliveries and complete rubbish [1]. Measuring how each approach effects the bowling at the other end is difficult though, and will have to wait until I can see a nice (inexpensive) way of doing it.

The second measure is to consider it as a selection problem between two bowlers, all other factors being equal. For this, a simple though experiment will suffice.

Suppose we have two bowlers, each of whom bowl 30 overs. One takes 5/150 (MacGill), the other 3/90 (Bracken) [2]. Who is the better option to select?

At first glance you might take MacGill for his five wickets and superior strike-rate. But it really depends on how the bowling at the other end performed. In the case of Australia, the other end is likely to be Warne and McGrath, each of whom average in the low 20s. If those two bowlers combined to take the two remaining wickets at a cost of 50 runs, then the combined figures would be 5/150 for MacGill versus 5/140 for Bracken and co. Given those initial conditions, MacGill would need to average 28 to Bracken's 30 to be as good an option.

If you have the situation that occured during the Ashes, when one player (Warne) is getting wickets at close to 20, then a player who can hold up one end, regardless of his average, is very valuable indeed. This is why MacGill is a worse bet than Bracken [3]. His strike-rate might be better, but their averages are close enough that Bracken's ability to slow the scoring effectively gives Warne and McGrath more runs to play with.

[1] As we always said in the juniors, and for that matter, the fours: "shit gets wickets"
[2] I've marginally exaggerated the difference between what you'd expect from MacGill and Bracken, but the general principle still holds.
[3] Except in Sydney, where MacGill's average is substantially lower and he is one of the strike bowlers.

Cricket - Analysis 3rd November, 2005 19:39:06   [#] [4 comments] 

The Mechanics of Off-Spin
Russell Degnan

Or why they all chuck occasionally

When it comes to chucking, there is a lot of spurious things said, including by many people who should know better. Scott Wickstein has weighed in on some comments by Ambidextri when he said (amongst other things) that " Umpires cannot decide on their own whim to call him, and certainly cannot see with the naked eye if a delivery is legal or not.".

This is plain rubbish. Umpires are well placed to judge on a straightening of the arm beyond a certain point. 10 degrees, the legal limit for fast bowlers, is very noticeable, even at high speed. The animation below demonstrates 10-degree flexing, at the typical speed an umpire will see.

The baggy sleeves of today's players aside it is quite obvious and bowlers should be called if they are flexing anything like that amount. Murali's doosra is apparently 14 degrees, but can be bowled at 10.2 degrees. Both of which are throws. Both of which should be called.

But that is not the whole story at all. These figures are (presumably) averages over many trials. No ball is bowled exactly the same, and a lot of bowlers will exhibit some degree of flexing on delivery. An often forgotten point - particularly with the stigma attached to being branded a 'chucker' - is that no bowler throws every ball, and most bowlers will throw a few. A bowler can feel when they have chucked it, in the elbow. I do it when I have no rythym, bowling mediums, on the odd occasion. Bowling off-spin, far more often, because of the nature of it as I'll explain below - but I don't bowl them outside the nets.

In the '50s and early '60s when the adminstrators tried to crack down on chucking, laws were created that required cautions, and the removal of bowlers who bowled no-balls. This, in my opinion, was wrong. It creates too large an expectation that a bowler will never throw. In reality, it is not substantially different to over-stepping the line. It shouldn't happen, but it does.

Off-spinners are particularly susceptible to chucking because they are roll their fingers in the same direction their elbow points - and therefore will naturally straighten their arm if it wasn't already straight. The classical off-spinner - Tim May for instance - pivots on their front foot, rotating from side to front on, and having their elbow pointing towards square leg. The image below shows a top down shot before the ball is bowled and a shot from behind on release.

The second image shows the advantage gained by a bent elbow. Straightening and propelling the ball in the direction of the spin, gaining both pace and turn.

Muralitharan bowls differently to a classical off-spinner, and is even more susceptible to throwing as a result. He is almost front-on as he gets to the wicket, with his elbow pointing down. On release, the elbow points down the pitch and the ball is rolled off the fingers generating extra turn.

It is not impossible to bowl it legally and the majority of the time he does so. But it is very very difficult to bring the arm through with the elbow pointing down without it being bent, and as such, the likelihood of straightening it as the fingers are opened is very high.

For the doosra, it is harder still. The arm comes through in the same way but is then twisted so the hand can be cocked to the right of the ball, making it even more likely to be bent, and even more likely to be straightened on release.

It isn't an issue of "is Murali or anyone else a chucker?". Sometimes he does, and because of his action is far more likely to than most other bowlers. On the doosra, the majority of the time I think it is being thrown - but that doesn't mean it can't be modified to be legal.

Instead of extensive tests in which a bowler can show a minimally acceptably type of bowling, the ICC should return to a simpler, fairer system, more in keeping with the spirit of the game. I'd do it as follows:

1. If in the umpire's opinion the ball was thrown the bowler should be quietly advised that the umpire was concerned and will be watching.

2. Subsequent balls of a questionable nature should be called no-ball. No further action should take place. If a bowler is unable to continue bowling without throwing then it is the captain's responsibility to remove him from the attack.

3. At the end of each day's play, the umpiring review that is conducted using the television replays should include all no-ball decisions - if any - to keep a standard level of leniency and ensure the umpires are capable of calling no-balls.

Finally, because of the mess the ICC has created, and the difficulty for bowlers used to throwing the ball whenever they feel; I'd phase it in over two years, where umpires inform the bowler that a ball would be a no-ball. Each call would then be assessed at the end of the day to ensure that adequate standards will being attained when the law is changed.

But the laws have to change somehow. One, because it isn't in the interests of the game to have a fractious and expensive system of administration for the laws of play. And two, such a system is only feasible at the upper levels of the sport. Despite what the ICC seems to think, there are people playing cricket who aren't test cricketers.

Cricket - Analysis 7th June, 2004 03:13:23   [#] [0 comments] 

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