In a TAC game instance, the only information available to agents is the ask prices--individual bids are not visible. After each game, transaction-by-transaction data is available, but the lack of within-game information precluded competitors from using detailed models of opponent strategies in decision making. ATTac-2000 instead adapts its behavior on-line in three different ways: adaptable timing of bidding modes; adaptable allocation strategy; and adaptable hotel bidding.