What's likely to be the final sticking point in negotiations?

If you're the optimistic sort, you probably looked at Monday's face-to-face meetings between Major League Baseball owners and player representatives, which took up most of the afternoon in Jupiter, Fla., as encouraging news. At last they two sides were talking in person, with actual participants involved, extending and reacting to competing offers, caucusing in separate corners for a while, then returning to present counteroffers before breaking for the day.

If you're the pessimistic type, you probably looked at it as just the latest in a long string of meetings that sounded good on the surface but ultimately saw the two sides remain far apart and seemingly no closer to a new collective bargaining agreement that will bring an end to the lockout and allow opening day to proceed as scheduled.

The true answer probably lies somewhere in between. The fact they did meet in person, and not simply for 15 minutes before declaring the just-presented offer fruitless, was a good thing. There was, for the first time throughout this interminable process, some acknowledgement of urgency, with the clock ticking down to the do-or-die moment less than one week away.

But let's not suggest there was some significant breakthrough during Monday's proceedings, because by all accounts there wasn't. The two sides each made some minor concessions, but they're still nowhere close to finding common ground.

The most encouraging development, it would seem, is that much of the disagreement at this point is over figures, not philosophies.

The league is willing to create a pool of bonus money to be paid to the best pre-arbitration players in the sport. The union just wants that pool to be larger, both in dollars and in the number of players who qualify.

The league is willing to institute a draft lottery, ending decades of precedent that automatically gave the No. 1 draft pick to the team with the previous season's worst record. It's just a matter of agreeing how many teams will be part of that lottery. (MLB wants fewer teams, the MLB Players Association wants more.)

The league is willing to increase the minimum salary. Just not as much as the players want it to be increased.

You have to believe - again, this is the optimistic view - that before week's end, the two sides can negotiate their way towards some acceptable numbers in the middle. It may not be what either truly wants, but it won't be the other wants, either. (This is generally now negotiations work in all walks of life, right?)

Point is, it's tough to see that being the ultimate sticking point that prevents a deal from taking place and thus prevents opening day from taking place March 31.

What, though, is likely to be the ultimate sticking point? What aspect of these negotiations are the sides least willing to move on, perhaps so much so they're willing to move the sport into what commissioner Rob Manfred already declared would be a "disastrous" outcome for everyone?

By all accounts, it sure looks like it's going to come down to the competitive balance tax, better known to most as the luxury tax.

First instituted in 1997 and a constant in the sport since (with the exception of 2000-02), the luxury tax was designed to serve as a deterrent for big-market clubs to excessively outspend small-market clubs, and in theory promote more competitive balance (a.k.a. parity). The problem, as the players see it, is that too many clubs treat the CBT like a hard salary cap, refusing to go over it and suffer the financial penalties that come with it. At the same time, a handful of the same small-market clubs continue to spend far less than their counterparts on salaries because there's no league-wide minimum payroll requirement.

The MLBPA ideally would like to eliminate the luxury tax altogether, giving every club the freedom to spend as much on payroll as it wants, while also pressuring small-market clubs to spend more than they have been spending.

MLB insists the CBT is critical to the sport maintaining some level of competitive balance. (As has been pointed out here before, 15 different clubs have won the World Series in the last 21 years, most of any of the major North American professional leagues.)

The league has been willing to increase the annual CBT number to appease the union, but not nearly as much as players want. MLB also is trying to increase the penalties incurred by clubs if they go over, something the union adamantly opposes.

If there's one issue that could take these negotiations down to the wire, this seems like the one. It's not just about numbers. It's about philosophy. The players believe this system keep salaries down across the board. The league insists it's necessary to ensure competitive balance.

Neither has shown much willingness to budge on this front. They've got less than a week to figure out something satisfactory to both sides.