The agreement between owners and players in the last CBA calls for roughly splitting revenue 50/50 and also splitting the coming losses. So, the owners want to hold back a percentage of players’ checks going forward — both giving them extra money they can use now, if needed, and also to help balance the books in the event some, or all, of the remainder of the season is canceled. From an economic standpoint, both sides would prefer to limit the pain of the shutdown to only this season and not start next season with IOUs on the ledger. Setting the money aside now would help do that.