KotDB: Weigh the BKRs based on the number of games of each type played. That should give a decent BKR for all types. If a player has not played at least four (since that's what BK requires to have a rating in any game) games of each particular variant, then they would be unrated for purposes of this discussion and if they have not completed at least 25 games of each type, then they would be provisional. I'm not sure if anyone has completed enough games of all types, but perhaps someone else can look that up. ;-)