Friday 27 May 2011

Weighted random number generator

I appreciate XKCD as a web-comic. Being a maths teacher and general geek, a lot of his humor strikes a chord with me.

Today's one did make me think at first. How realistic is this?

Often with cricket we appreciate more than the score. A beautiful cover drive through the gap is worth the same on the scoreboard as an edge past the keeper, or a hoick across the line that is fumbled in the outfield for 4. And yet we value one more than the others.

The aesthetic of cricket is something that an amateur statistician like myself can't quantify, and yet it is part of what keeps drawing me back to the game. The sound of a well struck boundary. The battle of wits between a wily spinner and a temperamental batsman. These are more important that the wins and losses. These are why I do statistics: to somehow make my contribution to the beauty of the game.

I find it difficult to explain to people why I will give up seven hours on a Saturday to umpire a cricket match. People don't know why I would want to go and sit up on the bank at a first class cricket match. And it is really difficult to convey how much I enjoy lying in bed on a rainy winters evening and listening to cricket coverage on the radio from the other side of the world. But likewise I have difficulty explaining how numbers, patterns and mathematical relationships can be beautiful. There is a beauty in the mathematical world that matches anything that the arts can produce, and for me cricket statistics can be an overlap between these two worlds.

Often this beauty is passed over by the casual observer. The beauty of both the mathematical world and the world of the true cricket tragic are inaccessible to someone who has only scratched the surface. To the casual observer a six is more exciting than a quick single, and a T20 match where both teams score close to 200 is much more exciting than an ODI game where a team defends 175. But to the purist this is almost the opposite of true. Likewise to the general public a mathematician is someone who is good at long division, whereas most mathematicians find arithmetic almost irrelevant to what they do.

My father has a theory that the downfall of the British Empire was due to test cricket. That enjoying an activity that lasted for 5 days without producing a result induced a decline in the attitude that defined Britishness. For me this ignores the beauty in the narrative. The thing that XKCD got wrong was that the narrative isn't built in the numbers, but instead that the numbers help tell the story.

And this leads me to this blog. Am I guilty of using the numbers to generate the stories rather than using them to support them? I hope not. Normally my statistics start from a hunch about a player that I've watched, and am looking for evidence on. Sometimes they surprise me, and the surprise is often worth mentioning. (such as Dilshan and Sehwag being so good at scoring non-boundary runs.)

Ultimately I think that the XKCD comic makes an interesting point, but it misses the mark: just as this one from SMBC does:

ps: yes I understand that they deliberately exaggerated for the point of humour, but it is only funny because it contains an element of truth.


  1. Ummm...well...the cartoons are cool :-D

  2. (Yeah, I came here today via cricinfo :) )

    The point of the comic is not so much that all that happens in sports can be expressed by a number. Although it is implied to be part of the story.

    It is the invention of narratives. Like calling teams that perform better than expected "scrappy" or "resilient" when it is possible or more plausible that they have been undervalued both intuitively and statistically up to that point, there are other helpful factors, or they just got lucky.

    This may even be the result of misusing statistics. As in labeling some players specialists of one format because of their stats in a small sample size, and then selecting them over players who are not perceived to be specialists in that format, but should be expected to perform better anyway.

    Or, in other words, what the comic is satirizing is that if your father claimed that Test cricket was the exact and only reason for "the downfall of the British empire", and not just a theory.

  3. I agree Rikki - but the comic did make me think about how easy it is to read more into the statistics than are actually there.