ELO and screenshots

Hi all.

Just two questions:

1. How many games (of a certain gametype) do I have to play in order to gain a real, not preliminary, ELO?
2. Where does Xonotic store screenshots? I did some shots, but I failed to find them, also by searching all files with the string "xonotic" in the name. I use Ubuntu 11.10 32 bit.

Thanks in advance.

Screenshots are stored in ~/.xonotic/data/screenshots. If you don't know that syntax, ~ means your home directory. It's a hidden directory because it starts with a dot.

No idea about the stats system, I'll let others answer that.

32 is the magic number afaik

"Preliminary" just means that you don't show up in the ranks (see Leaderboard) yet and yes, you need 32 games per gamemode for that.
Those rankings update once a day, so don't get confused if the Elo of a player is different in the ranks and his profile.

Ok, thanks all. Just for trivia, how is ELO calculated? Is there an explicit formula?

Elo rating system on Wikipedia

See in the Xonstat source code: xonstat/elo.py and xonstat/models.py (update_elos function)

I really need to write that blog post about Elo and how XonStat uses it. For now let me say a few things:

1) The Elo algorithm is up on Wikipedia here: http://en.wikipedia.org/wiki/Elo_rating_...al_details. I really can't write up the mathematics behind it any better than that! We're using an initial K value of 200, which then drifts down to 40 over 32 games.
2) XonStat uses score per second as the input to the Elo algorithm
3) Scores for team games are normalized. This is where the most complex stuff outside of the actual Elo algorithm occurs, and this is the area which I think deserves more clarification.

Ty. I reached 32 CTF games an hour ago, but my ELO is still reported as preliminary. Do I have to wait the end of the day or when global stats will be updated?

http://stats.xonotic.org/player/4873

Your next CTF game (the 33rd) will put you into the rankings somewhere.

Yaeh, stats are being synchronized every 24 hours.

Again, I just played my 33rd CTF game, but ELO is still preliminary.

As said above, stats are updated daily. Check again tomorrow?

Ok. But stats in my profile are updated immediately after a game, strange that Elo was updated but its preliminary (or not) nature no. :|

Perhaps because ELO needs actual computation that wouldn't be nice to run for every player on every match. I don't know. Let's wait a day :>

There are two things at play here - Elo and ranks. Elos are updated after each and every game. Ranks, however, are updated daily.

Here's some irc log:

Code:

Antibody | I will make changes to the view to make things more clear
Antibody | But basically - you can play in a game and it NOT count towards Elo
Antibody | Since we don't count games where you've joined with less than half of the match remaining.
Antibody | You have to play >= 50% of a match for it to count towards elo, in other words
MrBougo  | do I copy this into the thread?
Antibody | So if someone wins a DM match to 30 in 5 minutes, you'd have to play 2.5 mins for it to count
Antibody | Sure, if you want
Antibody | In this case 5 of his CTF games were below the limit, so he had 27 ctf games counting towards his elo. I bumped it up to 32 and he'll show up in ranks tomorrow morning.
Antibody | bumped it up to 33*

Here's some irc log:

Code:

Antibody | I will make changes to the view to make things more clear
Antibody | But basically - you can play in a game and it NOT count towards Elo
Antibody | Since we don't count games where you've joined with less than half of the match remaining.
Antibody | You have to play >= 50% of a match for it to count towards elo, in other words
MrBougo  | do I copy this into the thread?
Antibody | So if someone wins a DM match to 30 in 5 minutes, you'd have to play 2.5 mins for it to count
Antibody | Sure, if you want
Antibody | In this case 5 of his CTF games were below the limit, so he had 27 ctf games counting towards his elo. I bumped it up to 32 and he'll show up in ranks tomorrow morning.
Antibody | bumped it up to 33*

Understood, lots of thanks.

FYI you're up on the ranks now (on page 8 at the time of this writing).

I've seen, thanks again.