Hacker News Reader

Comment by boomboomsubban | Hacker News Reader

The World Cup is about the worst sporting event for data led predictions like this, far too much can rely on a few events that are basically a coin flip. It would be interesting to see how the predictions went for something like the Premiere League tables.

View on HN

Premiere League is over a far too long period of time with variables that can change completely without prediction (managers getting sacked, players leaving / joining, etc).

The reasons events like the World Cup are far more interesting is because it's over a shorter period of time.

I think the problem here isn't the event but rather the sport. Something like snooker or tennis will offer the same brevity over the period but with chance playing a less significant role due to the number of games played per match.

That all said, if my years of watching snooker has taught me anything, it's that people are not machines and thus will perform vastly different from day to day depending on how what mood they're in.

Interesting observations here about team sports have a bunch of extra opportunities for randomness. Do you know if there's anything equivalent to Fargo Rate for snooker (or other individual sports like tennis)?

I'd like to see some scientific evidence of this (i.e. using multiple experiments, null hypothesis, etc.)

I think that you have to come at this from an analytical direction rather than an empirical one; the problem is that everyone can say that the approaches that you have used to show how difficult it is to model the world cup are just the wrong ones and you need to redo the experiment.

Analytically the difference between premier league and the world cup is that you have momentum and continuity in the premier league and the world cup is essentially one shot. So in the PL team A will play team E and G and H before it plays team B, team B may play team E and H and Q (which played G). Team A may be winning games that your strength model shows they should lose, Team B may be losing games... and so on and so on. There is more evidence that might matter. More importantly you can be wrong quite a lot of the time in a season and still be right at the end of it (as the bounces of the ball even out over time). Not so much in the world cup - one goal knocks you out and there is no coming back! Basically the world cup demands an algorithm that works with less evidence and with a much higher degree of accuracy.

> far too much can rely on a few events that are basically a coin flip

Can you give us some examples?

As there are relatively few goals, anything that can turn a goal into not a goal or vice versa can have a massive impact on the game. For example the penalty decision against Croatia in the final. Another thing that adds to the randomness is the chance that a key player may be sent off or injured.

To make that be specific -- in 44 of 64 games, and in every single penalty shoot-out, turning one goal into not a goal or vice-versa would've changed the outcome.

It is not so simple because goals in football are not independent from each other. A team that scores first has the opportunity to play more cautiously and go for more counter attacks.

For example: Croatia got to the final via two penalty shootouts, which is very much like coin flipping.

Can't you put probabilities on that though? What you said is basically "impossible to predict, because one or the other might score more goals, so it's like coin flipping."

You can put probabilities on it, but the chance a game ends tied is rather high to begin with. 25% of this years knockout games were draws, and a 1/4 chance the game is decided by a coin flip is already enough to ruin predictions.

Someone deciding to handball the ball out of the way, a tackle that goes harder in a temper flare. A penalty that is saved/missed

It's an incredibly low scoring sport with a single-elimination bracket. A fluke goal can swing the whole bracket.

In the NBA, NHL, or MLB, seven game series tend to even out the variance, so the best team usually wins. And even in NCAA basketball, there's enough scoring that any individual play loses significance.

Reply on news.ycombinator.com