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Show HN: Euro 2016 predictions using Bayesian inference

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Re: Show HN: Euro 2016 predictions using Bayesian inference

#41

Post by tremon »

r3bl wrote: post #33
Grue3 wrote: post #14

I can say right off the bat this is completely wrong. The sum of probabilities of each team winning cannot be 100%. Why? Because draws exist. Worse yet, the concept of "playing for a draw" based on your current position in the group also exists. Also, the concept of "nothing to play for", when the team is already guaranteed the first place in the group and might not play at full strength in the final game.

Yes, the draws exist, but every other argument you've posted cannot be applied to the first round of group games. Chances are huge that all of the times are going to want to start strong. As the researchers said multiple times, they're going to be updating their algorithms all of the time and take into account the things they've missed in the current version.

Chances are huge that all of the times are going to want to start strong.

Except when you're the lowest-ranked team, and starting your group with a match against the favourite. In that case, you're likely to play for damage control (e.g. aim for a draw, don't concede too many goals).

Re: Show HN: Euro 2016 predictions using Bayesian inference

#42

Post by School-Cotton »

antouank wrote: post #10
heinrich5991 wrote: post #8

Earlier quoted context omitted.

In chess you can also have a draw. Either by having the player agree to a draw, or by killing every piece that is not the kings.

Right. But then again, you cannot say it's 100% that player A or player B will win, right? There's a chance for draw that is not negligible.

In fact, at top levels of play, draw rates are 40% or higher.

Re: Show HN: Euro 2016 predictions using Bayesian inference

#44

Post by riffraff »

interesting, the model seems very slightly confident that italy will win against belgium, even though it recently lost 3-1, and most rankings put the belgians ahead, and gut feelings say that italy's current team kinda sucks.

I really hope your model is right :)

EDIT: could it be you are underestimating the weight of player age?

Re: Show HN: Euro 2016 predictions using Bayesian inference

#45

Post by mlla »

lum wrote: post #2

For those who are interested in the details: we model the strength of teams using the well-know Elo model (used e.g., for official chess ratings). We innovated on two aspects of the traditional Elo model, in which every team has an independent parameter: 1) We actually model the strength of players instead of teams. This makes it possible to learn from games that were played in championships between clubs, and transf…

Have you had any chance to compare your player strength values against other models to check how well they are aligned? You can find from Premier League's web site "Player Performance Index", e.g. for last season the top three players according to PL PPI were Harry Kane, Riyad Mahrez and Jamie Vardy.

Another obvious question is that have you checked your model against the odds on betting sites that provide "Draw-no-bet" bets since you are not yet taking into account draws?

Re: Show HN: Euro 2016 predictions using Bayesian inference

#46

Post by semi-extrinsic »

huherto wrote: post #34
gloves wrote: post #3

Cool work! Appreciate it's not your mission to say 'this will or won't happen' and is just a bit of fun. But the great thing about football is that interesting as this is, I won't be placing any bets off the back of it. Too many variables in human nature, playing conditions, external factors, and maybe even luck . It's what keeps the game interesting and millions watching. It would be interesting as a question to won…

It is my personal opinion that soccer has a very high luck component. Often four or five plays decide the game. Frequently enough it is even decided by a referee call. It makes the game attractive because even an inferior team has a decent chance against a superior team. It may be just a lucky shot and then you close your defense.

> It may be just a lucky shot and then you close your defense.

See Greece in WC 2010 as an example of this as a deliberate strategy.

Re: Show HN: Euro 2016 predictions using Bayesian inference

#48

Post by vicow »

riffraff wrote: post #44

interesting, the model seems very slightly confident that italy will win against belgium, even though it recently lost 3-1, and most rankings put the belgians ahead, and gut feelings say that italy's current team kinda sucks. I really hope your model is right :) EDIT: could it be you are underestimating the weight of player age?

We are not considering the player's age as a feature at all actually.

Concerning the predictions, they depend on the starting 11 for each team. We took the most recent ones, i.e. during the last friendlies, which are probably not the ones that will actually start the game!

Re: Show HN: Euro 2016 predictions using Bayesian inference

#49

Post by octonion »

lum wrote: post #2

For those who are interested in the details: we model the strength of teams using the well-know Elo model (used e.g., for official chess ratings). We innovated on two aspects of the traditional Elo model, in which every team has an independent parameter: 1) We actually model the strength of players instead of teams. This makes it possible to learn from games that were played in championships between clubs, and transf…

What's a reference for the connection between Elo and Gaussian process classification that you mention?
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