Posts from June 2011

The Uncertain Eye

Tuesday 28th June 2011

As I was watching the match last night between Nadal and Del Potro, I started to wonder just how accurate the Hawk-Eye system is. Turns out that Hawk-Eye reckon that the average error of the system is 3.6mm. Which is actually pretty good, but is it good enough?

For most calls, yes, probably. When it’s clear that the ball landed on or off the line, the system is probably adequate; a few millimetres won’t change the call. But we often see it showing really close calls, where a few millimetres would make a difference. But as far as I can tell, in those cases the system is still trusted, the uncertainty of the measurement isn’t taken into account. Which seems a bit bizarre, really.

So given that for close calls Hawk-Eye isn’t accurate enough, should it be trusted as much as it is? Perhaps not. Or at the very least, the margin of error of the calculation should be displayed whenever the system is used.

On the Hawk-Eye website, there are several documents which look at controversial Hawk-Eye calls. For example, from the 2007 Wimbledon final where Hawk-Eye showed a shot to be in by 1mm (3.6mm uncertainty, remember), which looked from the camera to be out. Here’s a short clip:

The manufacturers recreated this shot and filmed it with high-speed cameras, to show that Hawk-Eye might not have been wrong in this instance. But that seems to me to be a bit backward; why not just use the high-speed cameras to check line calls in the matches? Then there would be a definitive record of what the ball actually did, rather than a back-calculated approximation of its movement.

Posted In: Geek Tagged: | 2 Comments

Planning fail

Wednesday 15th June 2011

I’m travelling down to Cardiff tomorrow to visit some friends, and because I’ve done the drive to Cardiff so many times that it’s become incredibly tedious, I’m going to go by train. So I went to to book my ticket, from Birmingham to one of the stations in Cardiff, via Cardiff Central (for reasons unknown, it won’t let me plan a route from my local station). Here is the journey that the online planner suggested. Note the first 3 stages:

Hmm. I think I’ll book my ticket elsewhere.

Posted In: Random Tagged: | 5 Comments


Saturday 4th June 2011

When I wrote about Closer To The Edge a few weeks ago, I mentioned that there was another motorsport documentary due to be released, this time about an F1 driver. The driver in question is Ayrton Senna, the Brazilian three-time world champion, and widely thought of as the greatest racing driver ever.

I went to see the movie today, and it’s brilliant. It’s quite a different form of documentary, because as much as possible the film makers have avoided using narrators or talking heads to tell the story; instead they’ve used footage and recordings of Senna from during his career, and so largely he is telling his own story as it’s unfolding. It’s extremely clever, helps bring everything to life and draw you into Senna’s story. And it’s a fascinating and dramatic story, told extremely well. For instance, the way the film builds the tension when the story gets to That Weekend – even from the first shot, taken from a helicopter as it flies towards and over Tamburello, which genuinely made me shudder – is really quite remarkable.

You do not have to be a petrolhead to appreciate this movie (I saw this with my Mum – who finds F1 boring – and I think she enjoyed it as much as I did). As with Closer To The Edge, it’s largely not about obsessing over this race and that, about watching and admiring what he did on the track. Instead it’s about Senna as a man, about what made him tick.

I can’t think of much more to say, other than to urge you to go and see this (and to see it at the cinema rather than waiting for the DVD; it’s definitely worth it). Even if  you have absolutely no interest in motorsport or F1 and think it’s the most boring thing in the world, you will not be disappointed by this movie.

Posted In: MotorsportMovies Tagged: | 2 Comments