Czuch: It is calculated at what the BKR's are at the end of the game.

I never liked this since if someone starts to time out on a lot of games, the first people who they start to time out with will get better BKR results... while those who time out in the later games once their opponent BKR is like 500 will get less.

But I understand why it is like this - since in most cases (not tons of time outs - but normal game playing), a persons BKR at the end of the game will more likely reflect their true rating. For example in the Knight Fight game, I started out really good with over 2000+ BKR after my first 4-15 games or so. But now my BKR is more reflective of my true talent in the game (1600 or something) so it makes more since to use the current rating to calculate the BKR change then my inflated 2000+ that I had by getting a lot of good early wins.)