Hrqls: You cannot count it as "win" or "loss". The formula has some input parameters - your current BKR, average BKR of all opponents, current BKR of each opponent, number of "wins" [players with lower final order], number of "draws" [players on the same level as you], number of "losses" [players with higher final order]. It takes all of this, makes some creepy things with them and spits out the result as your new BKR :-)
Well, the ratings are based on final positions of the particular pond players. When you have the last round of a finished pond, consider players behind you as your wins, players on the same position as draws and the rest as your losses. And, of course, their current BKR is significant for the BKR result.
What's the point of this endless discussion? I already have a rating system for pond games, it's just not activated yet. The goal is to keep the things easy and simple, which is the fact certain people still refuse to accept.