More or Less: How reliable is Kevin Pietersen?

Summary

More or Less: How Reliable is Kevin Pietersen?

BBC Radio 4 – December 3, 2012
Host: Tim Harford

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Episode Overview

This episode of "More or Less," hosted by Tim Harford, delves into two main topics:

1. The reliability of England cricketer Kevin Pietersen, specifically whether batting averages and statistics reflect his value to the team and his potential to deliver under pressure.
2. The mathematical question of whether zero is an even number, sparked by a real-world fuel rationing policy following Superstorm Sandy in New York City.

Using expert guests, the show unpacks these questions through clear analysis, memorable anecdotes, and a careful look at how numbers shape the narratives we tell in sport and life.

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Segment 1: Is Kevin Pietersen a Reliable Match-Winner?

[00:40–05:54]

Background and Listener Letter

• Host Tim Harford opens with skepticism about taking cricket batting averages at face value and introduces the question from listener Peter Harvey: "If your life depended on someone scoring a century, would you send Kevin Pietersen out to bat?"

Flaws in the Batting Average

Guest: Rob Eastaway, Association of Cricket Statisticians; Cricket Rankings Co-Inventor

• Limitations of Batting Average ([01:46])

  • “Averages are not a bad reflection of what you’ve done over a whole career, but they do have a number of flaws... They give no sense of how inconsistent a batsman is.” – Rob Eastaway ([01:46])
  • A batsman who alternates between scoring 0 and 100 will have the same average as one who scores 50 consistently.
  • No adjustment for the quality of the opposition or the match context.
  • Doesn't accurately capture current form; averages change slowly over a long career.

• Consistency vs. Match-Winning Potential ([02:19–03:14])

  • Harford: If you had one innings to save your life, “You want someone who's wildly inconsistent... who will occasionally score 100, otherwise you've got no chance.” ([02:39])
  • Eastaway: Cricketers debate this; a consistent batsman (e.g., Andrew Strauss) gives a solid base, but unlikely to produce “the spectacular match-winning performance as Kevin Pietersen did with his 186.” ([03:09])

Context Matters

• Quality of Opposition ([03:26])

  • “If you’re playing against a really strong side like Australia, then it’s going to be harder to score runs than … against Bangladesh.” – Rob Eastaway ([03:26])
  • Better statistics account for the quality of opposition and the proportion of team runs scored.

• Peterson vs. Ian Bell: Proportion of Team Runs ([03:57])

  • Pietersen: ~15% of England’s runs when he plays vs. Ian Bell’s 12.5%.
  • "There’s quite a gap there.” – Rob Eastaway ([03:57])

Inconsistency and Statistical Variability

• Measuring Inconsistency ([04:21])
  • Standard deviation is used to assess how much a player’s scores fluctuate.
  • Pietersen is “fairly middling” in inconsistency—neither a rock nor a pure wildcard. ([04:21])

Are All These Numbers Useful?

• Do Stats Help or Obscure? ([04:33])
  • Multiple ways to measure performance could make statistics confusing. ([04:33–04:46])
  • In the long run, averages “give a pretty good indication of how good he is,” but cricket is difficult to analyze due to limited data and a strong element of luck. ([04:55])
  • “A huge element of luck… These things can, you know, they will terminate your innings and make you look like you failed when you score when it wasn’t your fault.” – Rob Eastaway ([05:10])

Who Would You Bet On?

Fun Moments – "Bet your life/favorite slide rule"

• Harford: “Out of the current England batting lineup, who’s the man you would pick to go and score a century?” ([05:29])
• Eastaway:
  • Alistair Cook for England ([05:40])
  • Michael Clarke (Australia) among current world players ([05:46])
  • Donald Bradman all-time – “He scored a hundred every fourth innings or less. He was incredible batsman.” ([05:54])

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Segment 2: Is Zero an Even Number?

[06:01–08:54]

Real-World Context

• After Superstorm Sandy, New York City rations petrol based on license plates ending in odd or even numbers. Mayor Michael Bloomberg specified: “Those with license plates ending in an even number or the number 0 will be able to buy gas... on even-numbered days.” ([06:16])
• Host finds it “a little odd” to specify both even numbers and zero separately.

Mathematical Authority

Guest: Dr. James Grime, Millennium Maths Project, Cambridge

• Historical Parallel: France, 1977, used a similar car rationing system and “did not know whether to stop the 0 numbered license plates, and so they just let them pass because they didn’t know whether it was odd or even.” ([06:59])
• Are Mathematicians Agreed? ([07:26])
  • “Mathematicians are agreed that 0 is an even number.” – Dr. James Grime ([07:30])
  • “0 is an even number and it will pass every test and every definition of an even number.” ([07:32])

Definitions and Tests

• Tests for Evenness:
  • Doubling any number (e.g., 3×2=6, 0×2=0): Result is always even ([07:41])
  • Zero sits between the odd numbers +1 and -1 ([08:03])

Why Spell Out ‘Zero’ for the Public?

• Even if mathematicians agree, public confusion remains.
  • “Surveys into do school children think zero is even or odd... 50% thought zero was even... 20% thought it was odd... the remaining 30% thought it was either both or neither or they just didn’t know.” – Dr. James Grime, referencing surveys ([08:18–08:54])
• “The general public haven’t quite been able to handle yet... and I guess the general public would reflect that too.” ([08:54])

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Notable Quotes

• “You want someone who's wildly inconsistent rather than someone who always gets 40, 45, 50, 60 and then gets out. You want somebody who will occasionally score 100, otherwise you've got no chance.” – Tim Harford ([02:39])
• “Averages give no sense of how inconsistent a batsman is.” – Rob Eastaway ([01:46])
• “Kevin Pietersen's close to 15% when he plays, he scores about that, whereas Ian Bell is 12.5%.” – Rob Eastaway ([03:57])
• “He [Bradman] scored 100 every fourth innings or less. He was incredible batsman.” – Rob Eastaway ([05:54])
• “Mathematicians are agreed that 0 is an even number. It will pass every test and every definition of an even number.” – Dr. James Grime ([07:30–07:32])
• “50% of school children thought zero was even, which seems like good news. 20% thought it was odd...” – Dr. James Grime ([08:18])

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Key Timestamps

• 00:40: Introduction of the Pietersen question and listener letter
• 01:46: Rob Eastaway critiques cricket batting averages
• 02:19: Discussion on consistency vs. match-winning potential
• 03:26: Importance of opponent quality in batting statistics
• 03:57: Comparison of Pietersen and Bell’s contributions
• 04:21: Measuring consistency using standard deviation
• 05:29: Quick-fire: Who would you bet on for a century?
• 06:16: Mayor Bloomberg’s gas rationing rule for zero/evens
• 06:59: Grime recalls France letting zeros through in 1977
• 07:30: Mathematicians’ consensus: zero is even
• 08:18: Public confusion about zero’s parity

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In Summary

This episode deftly illustrates the complexity (and occasional absurdity) of interpreting numerical data in both sport and public policy. While cricket fans debate Pietersen’s real value, experts remind us that sometimes the numbers mask as much as they reveal. Meanwhile, on the mathematical question, the experts are unanimous: zero is even—even if public understanding lags.

Any cricket (or mathematics) fan can take solace in the fact that when it comes to numbers, it pays to ask the next question.

Transcript

[A]

Thank you for downloading from the BBC. For details of our complete range of podcasts and our terms of use, go to bbcworldserveys.com podcasts

[B]

hello and welcome to More or Less on the BBC World Service, your essential guide to numbers in the news and in life. And I'm Tim Harford. This week we'll be asking whether zero is an even number, following this from the Mayor of New York City, my Michael Bloomberg.

[C]

Those with license plates ending in an even number or the number 0 will be able to buy gas or diesel only on even numbered days, such as Saturday, November 10th.

[B]

But first, we're not ones to be churlish here on more or less, but we're here to ask some hard questions about England cricketer Kevin Peterson and the quality of his batting. I'm sure he can take it. He may be the darling of English cricket, but if your life depended on someone scoring a century, would you send Kevin Peterson out to Batman? Peter Harvey sent us a letter from Perth in Australia to ask us this very question and he also KP is

[D]

often likened to Marmite, love or hate, but nothing in between. If there is consistency, however, it's in the view that the English batting line up is weaker without him in support. His average score when in an England shirt is offered as evidence and he's often spoken of as a match winner we can't do without, but is he? Or can we?

[B]

So does Kevin Peterson's batting average tell us much about how well he might perform in this imaginary life saving challenge?

[E]

Rob Eastaway is a member of the

[B]

association of Cricket Statisticians and he co devised the International Cricket Council's World Rankings which were developed in order to address some of the flaws in the batting average.

[F]

Averages are not a bad reflection of what you've done over a whole career, but they do have a number of flaws, especially looking at a shorter period of time. First of all, they give no sense of how inconsistent a batsman is. If you get 0 100, naught 100, that's the same average as if you get 50 every time. They also take no account of who you've made those runs against or whether it was a low scoring match and they were more significant runs and they don't really reflect form either, so they will tend to deaden over your career. Your average moves less and less the more matches that you've played.

[E]

Rob, you've been thinking about Peter's question, I suppose two questions actually, Specifically on the question of betting your life on Kevin Peterson scoring a century, presumably you don't want a consistent batsman because a typical high quality batsman would average 45 or 50, wouldn't average anywhere near 100, which is a century. So you actually want someone who's wildly inconsistent rather than someone who always gets 40, 45, 50, 60 and then gets out. You want somebody who will occasionally score 100, otherwise you've got no chance.

[F]

Well, that's a really interest point and cricketers would argue that either way. So a consistent bat, it's nice to have someone, you know, you can rely on a good solid base for the team to build their innings around, someone who scores 50 every time. And someone like Andrew Strauss, who's now retired, was a good consistent batsman. But then, yes, they're unlikely to be the ones who do the spectacular match winning performance as Kevin Peterson did with his186.

[E]

Okay, so you, you're ducking this question absolutely. Of betting your life on a century. That's probably very sensible. We don't encourage such bets. So to come back to the question of whether he's valuable to the England team, you said the context matters.

[F]

Well, yes. If you're playing against a really strong side like Australia, then it's going to be harder to score runs than if you're playing against one of the weaker sides like Bangladesh. So what you'd really want to do is adjust the runs for the context of the game to say who's it against and what proportion of the team's runs are you actually scoring?

[E]

So how does Peterson rate? Does he make big scores when other

[B]

players are not scoring?

[E]

It's often said about Ian Bell, I think, that he only scores centuries when someone else has already scored a century. I mean, is that true about Bell and is Peterson different?

[F]

There is some truth in that. If you look at just proportion of teams runs scored, for example, Kevin Peterson's close to 15% when he plays, he scores about that, whereas ian bell is 12.5%. So there's quite a gap there.

[E]

And would you say that Kevin Peterson is an inconsistent batsman? He recently scored 186. The previous Test he scored 19. I'm no cricket expert, but that doesn't seem consistent.

[F]

One way you'd look at this would be looking at a player's scores and looking at what's called the standard deviation of those scores, how much they tend to fluctuate from the average. And Peterson is actually fairly middling in terms of that.

[E]

Let's just step back from this for a second. You've given us all kinds of different ways of measuring the performance of Kevin Peterson, the fact that there are so many different ways to measure it, does that mean the statistics aren't really telling

[B]

us anything at all?

[E]

Or are you a believer that actually collecting this kind of data could, could actually help? For instance, the England team managers pick the best players.

[F]

In the long run, a batsman's average over his whole career gives a pretty good indication of how good he is. I think cricket is a harder sport for the analysts to make decisions on compared to other sports, partly because the number of data points is actually rather smaller. You don't play that many innings and there is a huge element of luck that you're a perfectly good player, but due to some outrageous decision by the guy you're batting with, you might get yourself run out or there might be a brilliant catch and so on. And these things can, you know, they will terminate your innings and make you look like you failed when you score when it wasn't your fault.

[B]

Very good.

[E]

Well, Rob, let me pin you down. Now, I'm not going to ask you to bet your life. You're going to bet your favourite. Slide rule. Out of the current England batting lineup, who's the man you would pick to go and score a century?

[F]

I would pick Alistair Cook.

[E]

And of current active world players, who would you pick?

[F]

I would pick another captain, Michael Clark of Australia, who's in absolutely stupendous form.

[E]

And of any player in history, Donald Bradman.

[F]

He was stupendous. He scored 100 every fourth innings or less. He was incredible batsman.

[E]

Rob Eastaway.

[B]

In the wake of Superstorm Sandy, which battered the United States, New York authorities had to figure out a way of encouraging drivers to ration their gasoline consumption. The mayor, Michael Bloomberg, issued this directive.

[C]

Drivers in New York City who have license plates that end in an odd number or end in a letter or other character will be able to buy gas or diesel only on odd numbered days, such as tomorrow, which happens to be the ninth. Those with license plates ending in an even number or the number 0 will be able to buy gas or diesel only on even number days, such as Saturday, November 10th.

[B]

But why did Mayor Bloomberg say even numbers and zero? Was it necessary to single zero out? It seemed a little odd to us. So we talked to Dr. James Grime of the Millennium Maths Project at Cambridge University in the uk, and he says that a similar issue came up in France in the 1970s.

[G]

In 1977, the smog in Paris was so bad that they had to restrict car use. So they used the same method that they're using in New York now, alternating days for odd and even license plates, numbers did not know whether to stop the 0 numbered license plates, and so they just let them pass because they didn't know whether it was odd or even.

[B]

So it seems. Not everyone is sure. But do mathematicians agree over whether zero

[E]

is odd or even?

[G]

The debate is settled among mathematicians.

[E]

Mathematicians are agreed that 0 is an even number.

[G]

0 is an even number and it will pass every test and every definition of an even number.

[E]

What are the usual tests or definitions for even numbers?

[G]

If you take a number and you double it, the result will be an even number. So if you take the number three and you double it, then you'll get six and six is an even number. So that would be the definition of even numbers. And zero will pass that test. So if you double zero, you'll get zero, but it will pass all the other tests for even numbers as well. If you alternate the even and odd numbers, then zero is between two odd numbers, it's between one and minus one. That's another example of a test that it would pass.

[E]

So was Mayor Bloomberg being a bit daft to specify that rationing would apply to cars with even number plates or zero?

[G]

No, because it's something that the general public haven't quite been able to handle yet. There have been surveys into do school children think zero is even or odd? And it turned out 50% of school children thought zero was even, which seems like good news. 20% thought it was odd. And maybe the reasoning behind that is because you start counting from zero, it's the first number you start counting with, therefore it's odd. The remaining 30% of children thought it was either both or neither or they just didn't know. And I guess the general public would reflect that too.

[B]

Dr. James Grime. Our clock is ticking down to zero. And that's all for this week. For more information about the program, please go to our website, BBC.commoreorless and if you have any numbers you'd like us to look into, you can email more or lessbc.co.uk. goodbye.

[A]

There are dozens of different podcasts now available from the BBC, including news, documentaries, science, business, arts and sports. For details of them all, go to bbcworldservice.com podcasts.