Category: learning curve

Superbru’s Closeness Index Equation Is Copied From 1969 Apollo 11 Mission – But Might Just Work

Posted on

According to recent stats that we just made up, everyone in South Africa plays Superbru, the free online sports prediction game. I’m a veteran, having played and won Superbru pools in football, cricket and rugby over the last 5 years, including a top 2% finish in last year’s Rugby World Cup with over 130,000 players, and I’m looking forward to their Premiership and Tri-Nations Rugby Championship games starting this weekend.

While in rugby, you’re asked to predict the winner of the game and the winning margin, in football, you are asked to predict the actual score. You get points for predicting which team wins and you also get points for “being close” to the actual score. But what defines “closeness” in predicting football scores?

Superbru have devised their own system, resulting in what they call the “Closeness Index”:

We believe two things determine how close your pick was to the actual score. Goal difference shows how close you thought the game would be. But, a goal difference of 1 applies equally to 1-0 and 5-4. If the real result was 2-1, then surely the 1-0 is a better pick than 5-4?

Total number of goals helps us refine this. In the example above, there were 3 goals (2-1). One pick said there would be 1 goal (1-0) and the other 9 goals (5-4). 1 goal is closer to 3 than 9.

We factor both goal difference and total number of goals into a formula called the Closeness Index (CI). The lower your CI, the closer you were to the actual score (0.00 is a perfect pick).

All of which sounds very nice, but how exactly do they “factor both goal difference and total number of goals”. Well, they tell us this too:

Closeness Index (CI) = (your goal diff – actual goal diff) + ((your tot. goals – actual tot. goals) / 2)

Example:
Actual score: 2 – 1
Your prediction: 1 – 0

Closeness Index (CI) = (1 – 1) + ((1 – 3) / 2 )
= (0) + (-2 / 2 )
= 0 + 1
= 1

Well done. Extra marks for showing your working there.

However, eagle eyed astronomers and physics graduate readers will recongise that equation:

C = (b – a) + ((x – 1y)/2)

as being the lynchpin of the calculation used to safely land the LM-5 Lunar Module on the surface of the moon in 1969 (the only difference being the lack of the 0.15 correction factor for the gravitational pull of the moon). Now, using this formula may seem to be an unnecessarily complex (one small) step by Superbru, but you have to applaud their efforts in attempting to quantify the unquantifiable in order to make their game fairer. In addition (no pun intended), you’d do well to remember that this equation was successful in getting Neil et al onto the moon, so by my extrapolation, it’ll probably work really well in this scenario as well.

Of course, there will be those who will claim that since the moon landings were faked then the Superbru Closeness Index is also fundamentally flawed. For this reason, I will be making all my Premiership picks from a makeshift film studio in a Hollywood basement.

Stoke City to beat Reading 2-1. Near the Sea of Tranquillity. Probably.

ToS;DR

Posted on

ToS;DR stands for Terms Of Service; Didn’t Read.

We’ve all done it, haven’t we? Several times a week even. Checked that little box without actually reading what it is that we’re signing up for. Presuming that it’s just the standard stuff about reasonable use and copyright and stuff; the stuff that doesn’t really concern us, right?

But then why would we read all that stuff? Signing up for iTunes means agreeing to over 15,000 words of terms and conditions. And then there’s Dropbox, Play Store, Evernote, Flickr, YouTube, WordPress, 500px and so on and so on.
Add to that the fact that you probably won’t understand all the legal mumbo-jumbo anyway. And then remember that if you choose not to agree, you don’t get to use the service anyway. Want to play? Then there actually is no alternative but to check the box saying that you you read and understood, whether you actually read and understood or not.

It is “the biggest lie on the web”.

Thankfully ToS;DR is here to help with that:

ToS;DR aims at creating a transparent and peer-reviewed process to rate and analyse Terms of Service and Privacy Policies in order to create a rating from Class A to Class E.

Basically, key policies and conditions for each service are rated as “Good”, “Mediocre” or “Alert”. Based on those ratings, the ToS for each service are then rated from A (best) to E (worst).

It is a new system and they’re still very much setting things up. However, they’ve already rated a few services, including Twitpic (E) [not really surprising], Delicious (D), 500px (D) and Soundcloud (B). Click on the links in the Classification section and you can see the details on each of the points, explaining why they scored what they scored. It’s enlightening stuff.

They’re still collating information and scoring some big services like Skype, Twitter and Facebook. I’m intrigued to see what they come up with. Tos;DR is a useful service and a good first step at simplifying what is a ubiquitous, irritating and pretty much useless step on the internet.

93 seconds you’ll never get back

Posted on

Remember Leonhard Euler from the Satan’s Arithmetic post? Of course you do.
Now behold Euler’s Disc – probably the most hypnotic thing ever.

Look into the eyes, look into the eyes, not around the eyes… and you’re under…

The physics behind this “scientific toy” can be found here, but basically, it comes down to this:

A spinning/rolling disk ultimately comes to rest; and it does so quite abruptly, the final stage of motion being accompanied by a whirring sound of rapidly increasing frequency. As the disk rolls, the point P of rolling contact describes a circle that oscillates with a constant angular velocity w. If the motion is non-dissipative, w is constant and the motion persists forever, contrary to observation (since w is not constant in real life situations). In fact, precession rate of the axis of symmetry approaches a finite-time singularity modeled by a power law with exponent approximately -1/3 (depending on specific conditions).

So there you have it. Obviously,  it’s important that you remember that rolling friction is the primary mechanism for kinetic energy dissipation in this scenario and not air resistance.

Olympics infographic

Posted on

The BBC have put together a lovely infographic about the recently passed London 2012 games, including world records, attendances, athlete’s shape and size and the noise levels at some of the venues and events.

Oh – and that medal table.

Obviously, being of Yorkshire stock, this means that I am ever so athletic and stuff. Twice as much as people from South Africa.

Of course, had the Isle of Man been competing as a separate entity, it would sit proudly atop that “small countries” table, with Peter Kennaugh’s Team Pursuit gold in the Cycling to show for its 83,327 population. Being of Manx stock as well must therefore make me some sort of super athlete.

It’s no wonder that people keep randomly testing my urine. Maybe I should consider selling it to people like Peter Shardlow.

Bourbon Clear

Posted on

We met, by chance, in the Spur at the Waterfront. Me and my kids, him and (some of) his. A brief conversation ensued; the usual pleasantries, some congratulations on the latest addition to his family just 8 weeks ago. And then he asked if we had been to see the Rainbow Warrior and were we aware that we could go on board? We hadn’t, and I wasn’t.
He and I agree on many things, but we fall on very different sides of the lentil curtain.

I was aware that she was in town, but Greenpeace really isn’t my scene. He understood, but remarked (sagely, I felt):

Try to ignore the lefty, liberal agenda and just see it as a ship.

Fair enough, we were running a little late already, but the kids love ships.

We left him to his (free range?) ribs and headed down towards the Table Bay Hotel where the Rainbow Warrior is docked.

That’s when we saw it: the Bourbon Clear. (We also saw the Rainbow Warrior, but the queue for indoctrination looked a little long and I thought I might get sent for re-education if I accidentally let slip my views on whaling) (or fracking) (or nuclear power) (or hippies).

But anyway, the Bourbon Clear – what a ship! Norwegian registered and helpfully described as an “Multi-Purpose Offshore Vessel”, it has a long, low, flat stern with a MASSIVE bulbous bow section, a good five or six storeys above the water line. Weird, but ever so cool.

Once home, I popped onto marinetraffic.com (we’ve talked about them before here), and got all the facts and figures. And then I saw this photo:

When it said “Multi-Purpose”, I (foolishly) imagined it meant transport, towing, fire-fighting (those impressive water jets were evident) and the like. I never thought it meant sunbathing. But what a little (88m long) suntrap they’ve got going on there, hidden away from the rest of the world by those 6m high gunwales. And if the skipper says it’s ok, then why the hell not?

It wasn’t particularly sunny in Cape Town today, but from our position on the quayside, we couldn’t see into the back of the Bourbon Clear and I’m now left wondering what we missed behind the walls of green metal. A football match? A crazy golf course? A field full of wild horses? A clown convention?

I’d like to imagine that anything can happen on-board the Bourbon Clear.