What bout is the last clip from? ]]>

Pretty sure first-timers have to pay their own way….the guy next to me at JOs did. I was fortunate that my first national-level event was Summer Nats in Anaheim and I could drive there, so the cost was minimal….now I’ll be covered if I get on a crew again.

If I get an international event, I’ll probably have to pay my way the first time, tho,

]]>Looking harder, the Elo ratings are just silly. Here’s how they were calculated:

Elo rating= 1800+FIE points*3

That’s it. Provisional ratings simply do not mean “made up with a random formula”. They mean a best guess based on available data.

From what I can tell, the Elo ratings were first arbitrarily assigned based on that So, using the link here: http://en.wikipedia.org/wiki/Elo_rating_system#Mathematical_details , we can see that in the case of Men’s Epee, we have the resulting 86.6% for Nikolai Novosjolov in the first round. Hence, in the second round, Novosjolov has 0.866*(0.509*(P16)+0.491*P(17))=0.866*(0.509*0.794+0491*0.799)=0.69, where P(16) and P(17) is the probability for the #1 seed to win against the #16 and #17 seed respectively.

So an Elo rating obtained from a random formula has been arbitrarily assigned to each fencer, and then a DE table has been built from the top 32 fencers. Ignoring the fact that the world championship does not use such a format, the above tables do not tell us much, if anything, at all. It’s even wrong, because if one person wins against another, their Elo ratings change! It’s a nice proof of concept, but it really shouldn’t be advertised as anything close to a real-world model of the results, which is very confusing to the reader. This shouldn’t be advertised as science.

On the side note of Elo ratings, there are a few published analyses of Elo ratings discussing how a normal distribution can’t readily be assumed, and there have been reports of people sitting on their rating and in the case of something like chess, “Grandmaster Draws” (to conserve their energy), as well as issues such as rating inflation/deflation. In order to fix even some simple problem, you would have to have a specific Elo rating for each fencer in both poules and DEs, resulting in a lack of a information for DE prediction while poule bouts would be far more easily predicted, although in the case of poules, it becomes confusing because the margin of victory is suddenly important!

As noted in the post above (Frances’), a true Elo model would consider the difficulty in bouts much more than something like how far someone advanced, but it’s fraught with problems, because we would simply not have enough results over the course of a season (or even over many seasons) for the vast majority of fencers. Also, on a whim, I would guess that the results of individuals in any sport are far more variable than the results of any team. ]]>

Elo works fine for individual sports: it should be much more robust in dealing with things like injury absences than a simple cumulative point tally. The main issue is getting enough data points. In our experience at club level, 5-10 match results are enough to get a good fix on a fencer’s level, which means a pro going to every A-grade comp in a season and fencing at least one DE at each will have a reliable ranking. There’ll be a tendency to undervalue the guys who show up once and lose, but they’re not the ones the model is about anyway, to be honest. There’ll also be a tendency to underrate players who are highly erratic in their results, but hey, you can argue that’s perfectly fair.

The value of building a true Elo model based on DE results over a season would be to actually consider the difficulty of fights which (at least from my observation of men’s sabre) can be absurdly high even in the L64 and L32. To take a random example, someone like Bolade Apithy should get a lot more credit for taking out Kim Junghwan in the L32 in Warsaw, even if he then loses the next round. ]]>

A true Elo model for 2014/2015 based on A-grade comp results would be even more interesting. It’d be great to compare how it stacks up against the traditional points-based ranking the FIE is using. We’ve been using Elo at an internal club level for two years now and it’s incredibly powerful. In my experience, 5 matches is enough to get a reasonable fix, so a fencer who does the full world cup/grand prix circuit should be able to be ranked pretty accurately. ]]>