With one final proposal and one last ultimatum, the NBA put the wheels in motion Thursday for a delayed season that could begin Dec. 15, or perhaps not at all. After 23 hours of talks over two days, the league gave a revised offer to the players union, then said it was done negotiating. The union is expected to respond sometime next week, after a meeting of its executive board and player representatives. If the players approve the offer, a 72-game season could commence in mid-December. If they reject the deal, the NBA will replace it with a significantly worse proposal, one that virtually guarantees cancellation of the 2011-12 season and a legal battle. Commissioner David Stern specifically avoided terming this the NBA's last, best offer, although that was clearly what it was. “We have made our revised proposal, and we're not planning to make another one,” Stern said late Thursday night, adding, “There's really nothing left to negotiate about.” The offer is based on a 50-50 split of league revenues, which the union is resigned to accepting. But it also contains an array of new restrictions on player movement and team payrolls, all of which the union opposes, and which still threaten the approval of any deal. Those so-called system issues were the primary focus of the last two days of talks. The league moved slightly on one issue – the use of the midlevel exception by luxury tax-paying teams – and made other adjustments to its offer. Union officials were clearly disenchanted with the final version, however, and are reluctantly taking it to their members. “It's not the greatest proposal in the world,” said Billy Hunter, the union's executive director. “But I have an obligation to at least present it to our membership. So that's what we're going to do.” The player representatives of all 30 teams will meet with the executive board in Manhattan on either Monday or Tuesday to deliberate. They could accept the offer as is, reject it outright or – most likely – ask for more changes, despite Stern's vow not to negotiate further. “It's not going to get approved, as is,” one person aligned with the union said Thursday. “They've basically forced the union's hand, polling our guys to see what items are the deal-breakers.” It is unclear whether the union could call for a full membership vote, since the deal is technically not complete; there are 30 to 40 “B-list” items – such as drug testing, player discipline and days off – that have yet to be negotiated. If the union rejects the NBA's offer, Stern will replace it with a “reset” proposal: 47 percent for the players, with a hard salary cap and steep rollbacks on current salaries. Rather than take that deal, the union would probably opt for dissolution and file an antitrust lawsuit, moving the battle to the courts and wiping out the season. __