LA Times reports — The fatigue wore on their faces, but it hardly masked their enthusiasm.

NBA Commissioner David Stern smiled as he struggled recalling what day it was after wrapping up a 15-hour negotiating meeting early Thursday morning.

NBA Players Assn. executive director Billy Hunter smiled as he joked that players union vice president Maurice Evans should answer questions for him.

NBA Deputy Commissioner Adam Silver smiled when Stern needled him for “allowing all hell to break loose” when he missed last week’s contentious meeting because of flu symptoms.

National Basketball Players Assn. President Derek Fisher smiled when he acknowledged what he called a “slim” possibility both sides could salvage a full, albeit delayed 82-game season should they reach a deal by this weekend.

The reason for such a sudden mood change less than a week after talks broke off points to one simple reason: After reaching a stalemate on how to divide the basketball-related income, both sides instead talked about system issues. Neither side would quantify the exact progress. Stern still acknowledged the likelihood the league will scrap the games played in the last two weeks of the season. And he said, “There’s no deal on anything, unless there’s a deal on everything.” 

But the talks proved at least productive enough for another meeting to take place in New York at 2 p.m. EDT, with some optimism that Thursday’s meeting will bring both sides closer to a deal.

That a 15-hour-long meeting resulting in only undefined progress on system issues would bear such optimism surely reflects on slowly the lockout has proceeded. But it also shows owners and players recognize that they were better served focusing on that area rather than on the basketball-related income.

After all, that issue caused last week’s talks to end abruptly. The players union dropped their percentage from 53% to 52.5%, and even considered a bandwidth between 50%-53% depending on how much revenue the league accumulates. But Silver and San Antonio Spurs owner Peter Holt accused the players union of refusing to continue discussions unless they met their basketball-related income demands. Likewise, Hunter and Fisher accused the owners refusing to budge on a 50-50 split.

It’s possible meetings will go sour as soon as both sides return to that issue. But for now, the strategy shift at least has ensured more meetings, more agreements and more possibilities of brokering a deal.