Football Vandalism

Wikipedia defines vandalism as "ruthless destruction or spoiling of anything beautiful or venerable".

There are many motivations for vandalism: simple mischievousness, drawing attention to oneself, or even to draw attention to a political cause. Regardless of the merits of a political cause, though, vandalism is wrong because it destroys something beautiful, which causes harm to those who would have seen it.

There are always methods to draw attention to a cause without such collateral damage. That is why, ultimately, vandalism is an act of selfishness: by choosing this method, the vandal decides unilaterally that what is most important to him (a cause) outweighs the considerations of others (to see something beautiful). And whatever merits his cause may have, his selfishness must be condemned.

What does any of this have to do with football? This is what:

In case you didn't watch the match, it was a friendly between the USA and Brazil. Jermaine Jones put in a tough but fair tackle on Neymar, getting the ball, but then went through the player with his trailing leg. It appeared to be deliberate and Neymar hit the ground hard.

This tackle upset me and many others. Simply put, it was a dirty tackle. But even more upsetting was that the tackle was applauded by many USA fans. One proclaimed that he "loved it" and that this was the way to "send a message". Presumably, that message was that team USA is here to play hard.

I suppose I could complain about the message. What sense does it make to try to show the world how tough you are when it's a friendly... against an under 23 side?

But that's not the real problem. The real problem is that this is not how you send a message. You don't get people to appreciate your team by possibly injuring one of the best players in the world, a player who at age 20 is already mentioned in the same breath as Messi and Ronaldo. You don't get to potentially wreck his season or even his career because you think it's important to draw attention to yourself. That is vandalism. And ultimately, that is selfishness.

How Fantasy Football Explains the Stock Market

Managing a fantasy football team is surprisingly similar to managing a stock portfolio. In both, you have a fixed budget to spend on a fixed number of stocks / players (say, 15). Your job is to use all of your knowledge in order to predict which stocks / players are going to have the highest returns, be they in the form of dollars or fantasy points.

One fact that I think would surprise people to learn is that most managers of stock portfolios do worse than the market average. Of course, if every manager simply picked 15 stocks from the S&P 500 at random, then about half would do worse than average every year. But in fact, the vast majority of managers — some years, more than 80% — do worse than average.

A year ago, the idea that most professional portfolio managers, people whose full-time job is managing a stock portfolio, could be worse at picking stocks than choosing randomly was inconceivable. However, after another painful year of playing fantasy football, this now makes sense.

To explain, let's consider a hypothetical stock called "Vermaelen Industries". Here is a chart of the price of a share of this stock over the year:


If I were to show this price chart to an investor and tell him that I owned this stock for much of the year, that investor would most likely think I did well. Indeed, Vermaelen Industries had a good year. It went up in price. If I had bought and held it for pretty much any 10 week period, I would have made money.

Of course, Vermaelen Industries is fictitious, but this price chart is not made up. I've translated the points per week delivered by Arsenal centerback, Thomas Vermaelen, into changes in price. When Vermaelen delivered more than an average number of points, his price went up, and when he delivered fewer, his price went down.

Here is a chart of Vermaelen's points per week (ignoring the periods when he was injured):


Show this chart to any fantasy football manager and they will instinctively know the truth: I bought in game week 16 and sold in game week 25. Or in stock market terms, I bought high and sold low.

All fantasy football managers are aware of the fact that players tend to do worse after you buy them and better after you sell them. The fancy name for this phenomenon is mean reversion, but terminology aside, it is an instinctive law of nature to fantasy football managers. Indeed, it's effect is so strong that I feel I can make my favorite team win by selling all of their players and buying players from their rival.

Strangely, this law does not seem instinctive to portfolio managers. Nonetheless, mean reversion is just as real for stocks as it is for football players. And that, I think, is the root cause of why most portfolio managers do worse than the market.

One might think that the tendency to buy high and sell low is a result of irrational thinking. However, I think not. Rather, this behavior is the natural result of rational thinking combined with constant attention.

To explain, suppose that I am choosing, for one of my 15 stocks, between Vermaelen Industries and Kompany Manufacturing. Suppose that I currently own Kompany, but every week, I look at Vermaelen's results and decide if I want to trade.

In order to compare these two stocks, I need to predict the returns of each stock in the future. The simplest way to do that is to look at the average returns of each stock over the year so far. (Other, more sophisticated methods would also give the same result, but let's keep things simple.)

Each week, I will look at Vermaelen's average performance over the year so far and compare that to Kompany's. If Vermaelen's is sufficiently higher, then I will trade. Once I own Vermaelen, I will continue to compare, and if his average performance becomes sufficiently lower than Kompany's, then I will trade back.

With this methodology in mind, it should be less surprising that I bought in week 16 because that was the exact moment at which Vermaelen's average performance so far was at it's highest point. Likewise, it should be less surprising that I sold in week 25 because that was the exact moment when his average performance reached it's lowest point. Indeed, both trades were perfectly rational given current information.

As I've described things, however, I would still have needed some bad luck in order to buy and sell as I did. In particular, to buy in week 16, it must have been the case that week 16 was the first week at which Vermaelen's average performance so far became sufficiently higher than Kompany's. If, on the other hand, it was sufficiently higher at week 15 or 14, then I would have got in on a couple of good weeks and the trade would not look so bad in retrospect.

Reality, however, is not this nice. In particular, I would not have normally had my eye on just Kompany and Vermaelen. More likely is that I owned Kompany and then, at some point, it came to my attention that Vermaelen might be a good buy. Then I crunched the numbers and realized I should trade.

Of course, then we must ask: why did Vermaelen come to my attention? Obviously, he came to my attention in week 16 because he had a couple of fantastic weeks just before then. In general, the most likely time that a player will come to my attention is just after they have peaked. That is the time at which the player's accomplishments are most likely to be talked about (in the media, on twitter, or wherever) and thus come to my attention.

If I watch ESPN Press Pass every Monday, then each week I'm likely to hear about the players who are performing better than usual. Many of these are likely to be players that are peaking. So if this is how I find out about players for potential trades, then I am likely to see considerable mean reversion.

For portfolio managers, there is a simple way to avoid this: don't watch the news every week (i.e. "buy and hold"). However, fantasy football managers have little choice. We have to set our lineups every week, which requires current information about every player. So unfortunately, I can say with some confidence that our suffering will long continue.

On Diving

Another weekend of football comes with another set of questionable penalty decisions. In this post, I'd like to focus on two in particular: (1) the penalty awarded to Man City's Adam Johnson and (2) the penalty awarded to Man United's Danny Welbeck.

Much talk about the rightness or wrongness of these penalties is confused because there are many different questions we can ask. We can question the actions of the attacker or the decision of the referee or even the rules of the game themselves. There are many different questions we can ask, which have different answers. Here, I'll give my opinion on all of the questions I can see.

Was the attacker's action "wrong" (unsportsmanlike)? Yes, in both cases.

Both players went out of their way to make contact rather than trying to play the ball.

In Johnson's case, he kicked out his leg behind him hoping it would make contact with the defender, which it did. He took this action consciously, hoping for a penalty, rather than trying to play the ball. He clearly could have simply continued forward, going after the ball.

In Welbeck's case, rather than running toward the ball, he ran into the defender. The defender was not attempting to impede him. He purposefully decided to run into the defender and trip over him, while he clearly could have gone after the ball instead.

As a fan, I prefer it when players try to stay up even when there is contact. I prefer it when they try to avoid contact by running around or jumping over a leg that gets in their way. In short, I prefer players who act like Leo Messi. Unfortunately, Messi is a rarity in today's game in this aspect just as much as he is in terms of scoring and creating goals.

Was the attacker diving? No, in both cases.

Neither player "dived" in the sense that neither player simulated contact. Both players fell over because of real contact with the defender.

Was the attacker cheating? No, in both cases.

Neither attacker did anything that was against the rules or attempted to subvert the rules. As far as I'm aware, the rules do not award a yellow card for allowing yourself to be tripped.

Was the penalty decision correct? Johnson: questionable. Welbeck: more questionable.

I should first say: I am not a referee. Yes, I have read the laws of the game, but I have not spent hours studying them like religious texts, nor have I carefully read all of the guidance given to referees.

In real terms, however, both instances were of the type that you've seen sometimes given and other times not given.

If one wants to draw a distinction between the two cases, there is this: the defender in Johnson's case had stuck a leg out. In Welbeck's case, the defender (Ivanovic) had both feet firmly planted. While I wouldn't have had a complaint if Johnson's penalty had not been given, Welbeck's feels bad because it's hard to imagine what Ivanovic could have done differently. He defended well, went for the ball cleanly, and even appeared to be trying to stop himself from getting into the path of Welbeck. At the point of contact, he was not even in the path between where Welbeck was and the ball. (He was in the path of Welbeck's motion, but since the ball had moved away, Welbeck could have and should have turned as well.)

Should penalties be given in these situations? No, in both cases.

As I said above, I wish more players acted like Leo Messi, jumping over defender's legs and running around them instead of falling over at any contact. Unfortunately, the rules make this a bad decision for most players. Unlike Messi, most players are more likely to create a goal scoring opportunity by falling over than they are by continuing to play.

This needs to change. One idea is to allow referees to award yellow cards in situations like those of Johnson and Welbeck, where the player did not "dive" but did "go looking for it", trying to get contact with a defender instead of trying to play the ball. If such decisions could be made correctly, the game would be better for it.

That said, if the last few weeks are any evidence, the current laws already ask too much of the referees. So perhaps these changes would just give them more calls to get wrong....