Client java version

I think that's just the RoboRumble client prioritizing battles. From roborumble.txt:

# If set to SERVER (recommended), a new battle file is created which
# will first of all contain priority battles for robots that that has
# priority over other robots until they have fought a specific number
# of battles specified by the BATTLESPERBOT property. The number of
# battles fought by the individual robots are extracted from the
# rating files, which are downloaded from the server if the DOWNLOAD
# property is set to YES. When no more priority battles are left,
# robots from the participants file are paired at random similar to
# GENERAL.