Dec 13 2009

Averaging averages

Daniel Vettori has just now been dismissed for 134. That is a stunning return on the decision to promote him. And it’s not just his own score of 134 that is worth celebrating. Vettori came in with the score at 136/4, with a first-innings lead in the balance, and departed with the score at 408 and a humongous first innings lead of 185. At 6 he can not only save an innings, he can also build big innings. This also allows Tuffey to fill the roll shepherding the lower order.

This 134, by the way, has pushed Vettori’s average over 30 for the first time (excepting his first few matches). It also pushes his average in the no. 6 spot up to above 40.

An average in the 30s is great for a bowler, good for an all-rounder, but pretty average for a batsman. So it is disheartening to note that 4 of the 5 batsmen that bat above Vettori have averages in the 20s. (Taylor, currently the world’s 9th best batsman, is the exception).

Of course, all of the junior batsmen have played so few tests that their averages are pretty volatile. Daniel Flynn for example has only dropped below 30 in this series and would be back up again if he scored a century in the next innings. Though the more innings they have, the more confident we can be that their average reflects their ability.

There is a statistical value that can measure how confident we can be about an average, called the standard error of the mean. The larger the sample size (in this case, the number of innings), the more accurate the mean (batting average in this case). The standard error of the mean is calculated (assuming several things about the statistical distribution) by dividing the mean by the square root of the sample size. So we should be able to get a measure of the reliability of a batsman’s average by dividing it by the square root of the number of innings played.

So Daniel Flynn’s average of 28.7 off 29 innings has a standard error of about 5.3. My very rudimentary and rather naive interpretation of this sort of standard error is that we can be only 63% certain that he is not batting at an average of 30 or higher and has just been unlucky.

For Guptill (avg. 23.5, 14 innings) we can be only 93% certain that his average shouldn’t be 30. Whereas for McIntosh, we can be only 79% certain that he is not hiding an average of 30 behind his current average of 26.41 off 18 innings.

Now, B-J Watling, this test’s debutante, has scored a mere 18 runs, giving him a disappointing average of 18. However, the standard error of this average is itself 18. This means that even with this poor start to his career, we can only suggest with 83% certainty that he won’t score 30 runs in every innings here on in.

(Any of this make sense?)

By the way, we can be 99.8% certain Flynn shouldn’t be averaging 40, but only 96% certain for Watling. Two ways of saying “definitely” I suppose.


Mar 21 2009

Come back referral system, all is forgiven

Wouldn’t it be most fair for umpires to tend towards giving greater benefit of the doubt to a struggling team? I think it would, though I suspect in reality the opposite tends to happen. I mean, the Aussies never frickin’ seem to have their appeals turned down.

It is frankly inconceivable that Tendulkar’s catch off McIntosh was given without consultation with the third umpire after the precedent with Ryder’s catch off Dhoni (for which the on-field umpires conferred and consulted with the third umpire before giving it not-out). Both catches were equally dubious and the umpires should have treated them the same.

But what can you do but grumble. If the referral system was in place, nothing would have changed. Even though Tendulkar’s catch was equivalent to Ryder’s, if it had been referred by McIntosh, the third umpire wouldn’t have changed the on-field umpire’s call. It would be easier in a way however to be able to complain about been done in by “the system” than to feel hard done by inconsistent umpiring.

catch


Feb 25 2009

Next up, India

So India come to New Zealand even stronger than last time. All the talk is of them nabbing the no. 1 spot in the near future. And we’re well aware of where we sit in the rankings. However, the Indians have been notably short in bluster in the lead up the series. All the talk has been coming from Andy Moles. A tour of New Zealand is just the sort of experience that can bring a team back down to Earth. And the Indians are well aware of that and are perhaps even – could I be right in saying – a little scared.

Regardless of how the pitches are prepared, conditions in New Zealand will not favour India. This will go some way towards evening the odds. Suhas has made predictions for the results in the various rubbers. He’s probably got them all right. I am hoping that we can steal a test, but I’m not sticking my neck out and predicting that.

Players to watch

Martin Guptill/Tim McIntosh: I’m making a bold prediction of our test openers here, but both these players have impressed earlier in the season. What sort of a difference will it make to our test performances if we could build some decent opening partnerships?
Chris Martin/Kyle Mill/Mark Gillespie: If we have exciting promise at the top of our batting line up, our opening bowling spot is practically non-existent. A serious problem.

Ishant Sharma: He’s still learning the game really, but even his natural ability – and his height (1.95 m) – could make him devastating in bowler friendly conditions.
Virender Sehwag: Has been down in form over the past couple of years but has been keeping in touch with some massive scores. Averages 27 against New Zealand, so needs a lot of runs to fix that.


Dec 21 2008

McIntosh and his 100

Have we solved half our opening problem? Well, it’s too early to tell, but McIntosh is looking very exciting. You never know, he may be the saviour of another of our problems, that of scoring centuries.

The last century scored by a New Zealander (I think) was Taylor’s 154 at Manchester in May. To find the last century by an opener (ignoring Bell’s 107 against Bangladesh in January, unfairly perhaps, but it does get in the way of my point) we have to go way back to Nottingham ’04 for Fleming’s 117.


Dec 9 2008

Selections – the bats

The newspapers are all over the selections for the West Indies series. Rather than rephrase the debate in my own words, I thought I would look at the selections separately, starting with the batsmen.

Jamie How

Looking at How’s record, he must be charmed. He averages less then 25, but has outlasted a slew of other openers: Redmond most recently, but Bell before him, as well as Cumming, Papps and Hamish Marshall, most of whom have not done much worse than How. He did show some real class in the two series against England earlier this year, with 428 runs in 12 innings, and the legacy of that should keep his place in the team secure for at least the rest of the season. Also, with a career now amounting to 30 innings, he is our most experienced batsman (excluding McCullum) – a senior member of the team, believe it or not. With no one else really challenging for the spot, How’s experience and proven ability are valuable.

Tim McIntosh

The dark horse in the selection as he is the only debutant. In first-class cricket he has the ability to score really big. Already this season he has scored a 191 for Auckland, and last year he scored a 268, with a 205 the year before that. The problem he has is that aside from these big innings, he doesn’t get a hell of a lot of runs. In each season, about half his runs come from these big single hauls. To my mind, we want the opposite in the Black Caps; we want an opener who doesn’t necessarily get big scores, but always gets a start. McIntosh is due for a trial though – the next opener through the revolving door – and he is one of my players to watch for the series.

Daniel Flynn

Has little in the way of results to show (still working towards his first test 50), but has impressed with his technique and approach to the game. Worth persevering with then. The talk is that he will be promoted to 3, which I have already suggested would be a good move. Flynn might not do much better at 3, but the test will be whether Ryder does better at 5.

Ross Taylor

Shouldered with the responsibility of being our chief batsman since Flem’s retirement, and has responded well. We know he’s got more in him and we know we’ll see it as he gains experience.

Jesse Ryder

The wunderkind has had a distinctly average start to his test career. However, as long as he keeps his head, there is no reason he should ever be out of the team.

Brendon McCullum

The gloss seems to have come off McCullum recently. He was a superstar earlier this year due to this one-day exploits and his IPL paypacket, with commentators gushing about him being the new Gilchrist. In tests he doesn’t nearly live up to that hype – however, he still is one of our best batsmen. I think he is best at 7, where he gets the chance to graft a bit with the all-rounders, but also pick up bonus runs with the tail-enders against tiring bowlers.