The dead trees all report batting averages for the Ashes series. Averages, though, are only part of the story. One question you should ask about any statistic is: what sample is that taken from?
We should therefore also look at the standard deviation around the averages. Here they are, with averages in brackets.
Australia
Langer 30.8 (43.8)
Hayden 38.4 (35.3)
Ponting 46.1 (39.9)
Martyn 18.0 (19.8)
Clarke 23.7 (37.2)
Katich 22.6 (27.6)
Gilchrist 14.3 (22.6)
Warne 27.9 (27.7)
England
Trescothick 23.4 (43.1)
Strauss 42.3 (39.3)
Vaughan 48.2 (32.6)
Bell 23.2 (17.1)
Pietersen 43.1 (52.6)
Flintoff 35.0 (40.2)
Jones 24.7 (25.4)
What does this mean? A low standard deviation is a sign of consistency. Whether this is a good thing or not is, however, doubtful. Gilchrist and Bell have been consistent - consistently disappointing. And Trescothick's low standard deviation reflects a tendency for him to get out when well set - which is not good. Surprisingly (I think), Freddie Flintoff has been quite a consistent scorer.
Interpretation is also clouded by the small sample - Vaughan and Ponting look inconsistent because they both had one big innings - and by the fact that scores are not distributed as a bell curve; not even an Australian can score less than zero.
But the fact is that - especially over longer periods - a standard deviation can be a useful measure. If a batsman average 40, we might want to know whether this means he scores a string of decent innings, or a century alongside a few low scores.
Standard deviation is not the only statistic that should accompany averages. Another useful one would be a batsman's covariance with his team. A batsman who makes a big score when his side does well - a high covariance - is a flat track bully. But one who does well when his team does badly - a low covariance with the side - is good in a scrap. I suspect the careers of Atherton and Hussain would look good on this measure.
The fact is, there's more in the numbers than mere averages report. I could add skewness and kurtosis...
I'll get me anorak.
Another thing: Whilst I'm in credibility-lowering mode, I'll follow Norm in picking up the Geek's meme.
Person I fancy but wish I didn't: Kerry Katona.
Person other people fancy but I can't see why: Angelina Jolie.
O dear me. I diagnose a severe case of Anoraksia.
P.S. I agree about Angelina Jolie, but I think Liv Tylers a bit of a minger too, how say you?
Posted by: Rob Read | September 13, 2005 at 06:10 PM
Not just Liv. Most Hollywood actresses do nothing for me - Keira Knightley, Catherine Zeta-Jones, Nicole Kidman (not to mention the hideous Gwynnie). Too skinny and bland.
Sharon Stone and Helena Bonham Carter (yes, I know) are exceptions.
Is there something about the film screen (as distinct from the TV screen - loads of TV actresses are very nice) that explains this?
Posted by: chris | September 14, 2005 at 09:55 AM
shh... as soon as people start to take account of the little subtleties in player's averages (like Thorpe the ultimate scrapper or Lara 'get to 40, get to 140'), the bookies will get wise... let's not ruin a good thing, shall we? :)
Posted by: Paul Davies | September 14, 2005 at 12:39 PM