Less than two weeks from now, we'll know the full field of 64. Normally the picture is pretty clear by this point, but this season, there's still a lot on the line as the season winds down.

This week, we look at life on the fringes, where the final two trips through the rotation could make or break a season.

Let's start with the national seeds. Six teams -- Virginia, Florida, Oregon State, Florida State, Louisiana and Indiana -- are fairly secure as top-eight seeds. That leaves five teams competing for the final two spots.

Three of those teams are in the SEC -- Ole Miss, South Carolina and Vanderbilt.

The Rebels have the best record in conference play, but that number is somewhat misleading. Ole Miss is one of six SEC teams in the RPI top 25 but hasn't won a series against any of the others. It lost series to Alabama, LSU and South Carolina and didn't play either Florida or Vanderbilt. Even more troubling is the RPI rank of 15th -- no national seed has been that low since 2009, and an SEC team isn't likely to get the benefit of the doubt in that respect.

South Carolina and Vanderbilt have very similar résumés -- both are 16-11 in conference play, and the Gamecocks have one more win overall. But the Commodores have played a harder schedule, according to RPI, and have been much better away from home (14-7 compared to 8-8 for South Carolina). This one will be decided on the field this weekend, but for the moment, the advantage goes to Vanderbilt and its No. 7 RPI.

Miami and TCU are two of the hottest teams in the country. Each team has just two losses since the start of April and has moved up the conference standings -- Miami leads the ACC, while TCU is a game back in the Big 12. And the two are virtually back-to-back in RPI, with the Hurricanes No. 10 and the Horned Frogs No. 13. The difference comes down to record against top-25 opponents. TCU is 14-8, while Miami is 9-8.

This week, the last two national seeds go to TCU and Vanderbilt, with Miami hot on both teams' heels.

Things are similarly heated for the final two hosting spots. This week, it came down to four teams for the final two spots -- Houston, Louisville, LSU and Rice.

Like Ole Miss, LSU falls into a trap because of its relatively low RPI ranking, entering the week at No. 20. The lowest-ranked SEC team to host in the past three years was South Carolina, which was No. 13 in RPI entering the tournament last season. The Bayou Bengals are also sitting down in sixth place in the conference.

For the other three teams, we have head-to-head competition to help sort things out. Louisville swept a series at Houston, while Houston has taken two midweek meetings against Rice (with a third scheduled for Tuesday).

The rest of the numbers are quite similar. Rice leads Conference USA by one game, with Louisville tied for first and Houston three games back in the American. All three have played well away from home and have posted nearly identical records against top-50 opponents.

In lower-rated conferences, conference standing is often the deciding factor. The American is No. 7 in RPI, while Conference USA is a slot behind in eighth. That's enough to tilt the needle in favor of Louisville and Rice for the final two hosting spots.

As it does quite often, the "Last Teams In" debate comes down to power-conference teams that are further down the standings versus teams near the top of the smaller leagues. Let's take a quick look at the teams on or near the bubble this week along with some key numbers, then check out the bracket to see who's in.