So what is likely to happen?
From a strict business standpoint, the players' best move is to offer a counterproposal, and to be prepared to accept the league's proposal if their counterproposal is rejected. Perhaps one more bargaining session can be scheduled to hammer out an acceptable compromise.
But the players aren't operating from a strict business standpoint. They're angry. They feel that they haven't gotten a fair deal from the owners, and the only way to ensure a fair deal is to take the league to court. They are tired of making all the concessions. They are tired of being backed into the corner. They are tired of ultimatums. They're prepared to suffer the consequences of a canceled season.
It all comes down to Fisher, and how he intends to describe the league's proposal to the player representatives. If he describes it as the best deal the players are going to get and says the alternatives are too costly to consider, then the representatives -- and the players at large -- will follow his lead. If his description begins, "Here are the reasons this is still a bad deal," then the players will say "no," the owners' proposal will reset, and the union will likely decertify -- with a small window of opportunity to negotiate before the decertification becomes official.
So that's where we are now. The players have a number of options, but they really boil down to just two: They can accept the owners' proposal (or something close to it) and save the season or they can say "no," decertify their union, and likely kill it.
By delivering an ultimatum, Stern has put the season in the hands of the players -- and he's ensured a mid-November verdict. It's now up to the players to decide which is the lesser of two evils.