We did, it helps quite a lot! Concerning the model, we use Gaussian process classification with a logit link function, a linear kernel and Expectation Propagation as inference method.

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!

Could be, yes! We'll see after the Euro ;)

We tried to consider it as an extra player, but it didn't help.

Hi! I'm Victor, one of the researchers behind this project. We used the most recent lineups (up to yesterday) to do the predictions you see on the web page. We will update them with the latest friendlies (e.g., Portugal indeed) and before every game, as soon as we have the official lineups!

It may be worth taking competitive matches into account over friendly matches, as the purpose of competitive matches is to win at all cost. Friendly matches, on the other hand, tend to be used primarily for match fitness (especially leading up to tournaments), and for trialling new tactics before the competitive games begin.

Thanks for the clarification and great project!

It will be interesting to see how things change when you get the official lineups. As I'm sure you are aware, teams often rest their 'star' players in friendlies immediately prior to a tournament in order to minimize the risk of injury.