In the absence of any tangible content for the last few months, allow me to share what might be my favourite Onion story ever. I was reminded of it after listening to Todd Hanson’s recent interview on Marc Maron’s WTF podcast.
Sneaky Preview
19
Jul
So last night we were watching the CBC Edmonton news, which included a story about the closing of Sneak Preview, a video store with good selection of older, esoteric, and hard-to-find titles. (The story line was about finding a copy of “The Last Picture Show” which padded a 30-second story to 4 minutes, but I digress.)
I didn’t notice this before but there was something missing in the story. The co-owner of the shop, who was interviewed in the story, has a second job — as a video editor for CBC Edmonton. Isn’t this a pretty clear conflict of interest? As a sometime student of media, it strikes me that if you’re doing a story on a co-worker – even if that story is about the demise of your co-worker’s second job — it behooves you to mention the connection. No?
EPL Matchday 37 – Simulation
13
May
With only two games left in the Premier League season, many of the questions that I’ve been tracking with this simulation have been resolved, or it’s at the point where simulation analysis seems like overkill. In addition, some of the assumptions I’ve made in the simulation study – including how goal differential changes – may start to get in the way of useful analysis.
This will be the last update for the season, though I might run the simulation one more time just to see what it says before May 22. So here we go:
As always, the table shows the results of 10,000 runs of my simulation of the Premier League (background info here). Man Utd has every right to call the trophy engravers and Maserati dealerships after its win against Chelsea last week; while it’s still not a mathematical lock until they take a point from BlackX (where X = {burn, pool}), the chances of Chelsea pipping them for the title is 0.63%, or about 157-1.
Peter “praying mantis” Crouch (and, let’s be honest, their recent form) sunk Spurs hopes of another year in the Champions League (thankfully, this mathematical certainty reflects in the simulation, evidence I’m doing something right). But the reality is that since March, City has been ahead of Tottenham on probabilities even if the standings didn’t always reflect it.
On the other end of the table, the relegation picture is clearer and clearer, even though there are still 5 teams which were relegated in the simulation. West Ham’s 33 points give their chances of going down at 97%, and their game against Wigan this weekend, while not a “clinch” game, does make the path to the Championship much clearer. Blackpool was relegated 79% of the time, while in 35% of simulation runs Wolves went down. The two other teams that were relegated in the simulation were Birmingham (3%) and Blackburn (6%).
This is a useful example of how the simulation doesn’t predict every outcome. I have assumed that a win or loss changes each involved team’s goal differential by 1. This is a reasonable assumption when there are many games left, since blowout wins get offset by tight losses, and because when I update the stats every week the *actual* goal differential is brought to bear. However, with only a couple of games left, changes of +/- 1 to goal differential can overlook possibilities that might play out. My simulation did not have any runs where Villa was relegated. However, their survival is not guaranteed. Granted, to be relegated they would have to lose both of their games while 5 teams below them win at least one, which is unlikely. But more importantly for the simulation, Villa’s -13 goal differential is a lot better than the teams below them. In a tie on points they would win every time even though it’s possible that a blowout by Arsenal or Liverpool could erode their goal differential if things go sideways for Gerard Houlier’s side.
Here’s a chart summarizing the outcomes of each simulation I’ve run since the end of March:
This chart shows the results for the 6 simulations I ran beginning on 28 March, and graphs how each team’s expected finishing position has changed as the season has progressed. It uses a ranking based on the weighted average of each team’s position (for example, this week Man Utd’s weighted average rank is 1.006, which is obviously the #1 ranking). So even though Man City and Tottenham fought for that 4th spot, Man City was consistently more likely to get there in the end. It also shows Everton consistenly ranked over Bolton, though in reality the teams were hard fought right up to the last couple of weeks. Things below the top 8 were decidely more mixed. West Brom had a wild ride, as did Newcastle. And two of the three teams most likely to be relegated way back in March are still expected to go down.
Just one game-based analysis this week, and it’s the critical Wigan-West Ham battle. Here’s how the numbers play out:
The numbers show how critical this match is for both teams. West Ham will come out of the game with a high likelihood of going down regardless of what happens; even a win only improves their chances from “almost completely certain” to “somewhat less certain.” But a home win for Wigan lowers their chances of relegation from 80% to 60%, and sets up a chance to clear the drop in their last game in Stoke. The loser of the match is almost certainly relegated.
Okay, one more game analysis. Wolves have a chance to virtually book a place in the Premier League next season if they win against Sunderland this weekend. Even a draw slightly improves their chances. But a loss gives them essentially a 50-50 chance going into their final game against Blackburn Rovers.
As always, I would love to hear comments, questions, or rampant criticisms. Please feel free to drop me a line.
EPL Matchday 36
05
May
What a difference a week makes!
With most Premier League teams now looking down three more games in the regular season, the weekly simulation that I’ve been running (not so weekly) sees the numbers solidifying more and more. It’s been well established which 6-7 teams will occupy the top spot (though not quite as firm which would be in the bottom three). But the ordering is still wide open. Recent runs of form – both good and bad – by the top teams have kept the title race alive.
Without further ado, here’s the summary of my simulation after Sunday’s games were complete. Remember, the number indicates the number of times (out of 10,000 runs) that a particular team ended the season in a particular ranking:
EPL Matchday 35 – Simulation
28
Apr
Here we are with only four matches left for most teams (Tottenham and Man City being the exception, since their match was postponed until May due to the FA Cup). Even at this late stage, there is still ambiguity about who will end up where, and there are some massive games ahead.
As always, for some background on how these numbers are derived (and why, other than because your author is a big fat nerd), please check this backgrounder.
As of April 28 (up to and including Fulham’s 3-0 defeat of Bolton), the probabilities of each team achieving each position in the league table are as follows:
EPL Matchday 33 – Simulation
13
Apr
Here’s the results of my simulation run for the Barclay’s Premier League after the weekend matches. For some background information, please visit this backgrounder.
As of April 11 (including Liverpool’s 3-0 drubbing of Man City), the outcome of the simulation is as follows:
Premier League Probabilities – Backgrounder
13
Apr
A few years ago I taught a course at the U of A’s School of Business on simulation – the application of quantitative techniques to answer business questions where there is uncertainty or risk. For example, if you run a retail store and are trying to manage inventory, you need to have an idea of your demand so you can decide how much to stock. But demand is unknown – so, by using random variables based on previous demand, then repeating the analysis many times over, you can understand the effects of changes to your bottom line. That’s the power of simulation.
And, We’re Back.
08
Nov
It’s been a while, dear reader. Yes, singular – though I suspect even that one’s left. Apologies for the radio silence. Alas, we have lost our previous domain, pontificate.ca, to a scum-sucking, cretinous domain squatter, who has decided to put it to use driving traffic to @toronto, some generic squatter Twitter account, which I suppose has the benefit of actually being updated once in a while. Yes, I hope there will be more to this blog than some pedantic once-a-year posting. With that, I’m off to bed.
Soviet-Era Subways
12
Oct
An excellent slideshow of Russia’s various and uniformly artistic subways, courtesy of Treehugger. And from the same site, alternative subway maps.
Rethinking airline seat upgrades
18
Nov
Interesting post from the Economist’s travel blog: you can now upgrade your airline seat after boarding and taking off on some airlines. I’m fascinated by this as a student of logistics; empty seats on an airplane are the ultimate perishable good, meaning the value is lost the moment you pull back from the terminal gate. This is why airlines spend millions of dollars matching demand to price to ensure as much revenue is squeezed from the rest of the plane, and why it’s common practice to overbook a flight to account for no-shows (the cost of accommodating a bumped passenger is small compared to the cost of running with an empty seat). There are enough consumers out there who are cost-conscious enough to stick with economy seats, but human enough to think packing into a metal tube like a sardine is unpleasant, and this policy is geared to them. Imagine — you book your economy seat, then find you’re the middle seat between two “ample” colleagues. One quick swipe of a credit card and you’re up in front. Everyone wins; that much more room in coach class, you get to stretch your legs and enjoy a flight for once, the airline’s goodwill heightens with its customers, and the bottom line improves marginally as business class fills.