for kind of 1 year ago?
Ah, ok, I thought you meant like this is a regular occurrence. Yes, there was this issue right after a patch. And the single "The Don" game and the "Rzhev" games show that occasionally servers seem to do something unintended. But outside of these rare occurrences I haven't found a sign of certain maps being preferred by the system at certain days.
So it seems unlikely that the statistics are skewed by the algorithm that picks the map.
I still find it so funny: second place in 2vs2 is road to Kharkov. And in 3vs3 and 4vs4 port of Hamburg, the old port of Hamburg.
I guess the reason is, that you have a 50%chance to get the op side
Well, as ferwiner said, I think people typically tend to first and foremost veto maps where they think their faction has a disadvantage. I guess the next round goes to maps they dislike for other reasons (pathing issues, visuals, or general gameplay stuff).
For example, in 4v4 I typically tended to veto Hill 331 (because I disliked the pink soil) and Montargis (playing that with randoms comes down to who dugs in on the fuel hill first) and Redball Express (because I felt that to be too narrow with 4 players and I disliked the distinct lanes).
So, if the sides are unbalanced, sure might lead for some people to veto a map, but I don't think that that is something very high on the list of most players (although it might lead to players dropping quickly from a game when they find that they have to start from the side they consider at a disadvantage).
Secondly: I think most people will complain loudest about maps they actually play (rather then ones they never play because they consider those auto-vetoes). Maps they feel they are forced to play because they have to spend their vetoes on maps that are "clearly unplayable".
1. Do we know how the selection process works on the client side? Server side?
2. Say there are 10 maps. Most people would veto 2 of the same maps. Then their would be some variation of their other vetos. This would show graphically similar to your charts.
Re 1: We don't know, really, but judging from when stuff went wrong it seems to be server side.
Re 2: Still not sure what you mean exactly, but the fluctuations are expected. In the graph I plotted % to make it easier to see (obviously there will be different numbers of games from day to day), but the number of games isn't that big. The top maps achieve about 250 games per day, so a single team disliking one map and playing only one of those days easily can produce a noticeable dent for that map in the graph.
It is true tho, that the players with the current system
veto certain maps (for all I know the server then randomly picks the map from those maps that received the least amount of vetoes from all players in the match).
Instead, you could think of a system where you pick a map/maps that you would like to play on and the server would randomly pick one of the maps from those that got the most votes. I figure in this case the maps at the bottom would still be at the bottom, but the first couple of maps might be different ones....
Siphon can you link me the thread with stats before the dbp came, pls?
You mean
this one?