This time of year, a hefty majority of all questions submitted in our weekly college chat, as well as those sent via e-mail or Twitter, center around the battle for postseason positioning. Our readers want to know how the races for national seeds, host sites and at-large bids are shaping up—so it's time to roll out our weekly Stock Report feature. Every Tuesday here on the College Blog, we'll examine how the postseason picture has shifted over the weekend. Rather than get bogged down in the jigsaw puzzle that is a full field of 64 projection, we're not going to worry about which regionals teams get sent to. We're just looking at who's in, who's out, who's on the bubble. This discussion is based on performance through 12 weeks and projection based on remaining schedule, but it's also not intended to show what the field would look like if the season ended today. We're still looking ahead.

During this discussion, we will reference the NCAA's official RPI report, which is released every Tuesday and is updated through the weekend's games. We'll also reference the useful RPI Needs Report at Boyd's World, which provides a rough sketch of what teams need to do in order to reach important RPI benchmarks like finishing inside the top 45 (a loose target for an at-large bid). And we'll make use of records against the top 25, 50 or 100 in the RPI, using the official figures from the NCAA's Nitty Gritty Report..

We'll get to at-large chances in a bit, but let's start with a look at which teams are on track to earn national seeds and which are on track to host regionals through the first 12 weeks of the season:

National Seeds

SECURE TEAMS: Florida State, Baylor, Louisiana State, Florida

ON THE BUBBLE (IN): Oregon, South Carolina, North Carolina, UCLA

ON THE BUBBLE (OUT): Kentucky, Rice, Cal State Fullerton, Purdue, North Carolina State, Stanford

Changes from last week: South Carolina, Oregon and UCLA replace Kentucky, Rice and Stanford as national seeds.

Can the Southeastern Conference land four national seeds? It has four teams with top-eight-caliber resumes, but the best bet is for just three of them to land national seeds. South Carolina completely has reversed the damage of its slow start to SEC play (when it was swept by Kentucky and lost two of three at home to Florida), surging past the Wildcats into first place in the SEC East, tied with LSU for the best conference record in the SEC. A road series win at Arkansas bolstered South Carolina into very strong national seed position; the Gamecocks are now a more respectable 5-7 against the top 25 in the RPI (compared with Kentucky's 10-5). But the Gamecocks are also 6-0 against teams outside the top 150, while the Wildcats are 19-0. That soft nonconference schedule could still wind up preventing UK from landing a national seed.

Oregon has now won road series against UCLA, Stanford and Arizona, and it owns a home sweep of Arizona State. The Ducks sit alone atop the Pac-12, sitting pretty for a national seed, and their RPI has climbed to No. 6. The Bruins retain a robust RPI (No. 3) after taking two of three from No. 7 Purdue. UCLA's RPI and strong nonconference schedule offset its four series losses and fourth-place position in the Pac-12 standings. Stanford, meanwhile, squandered the momentum of its previous two weeks by going 1-3 last week to fall to No. 15 in the RPI.

Rice returned from its exam break to go 3-1 against Texas Southern and Houston, and while its RPI ranking fell to No. 18, the Owls can still finish among the top dozen or so with a strong finish (their schedule includes a huge series the final weekend at Central Florida). If Rice wins the C-USA regular-season and tournament titles, it figures to elbow its way into a national seed even if its RPI is outside the top eight (which it likely will be). A regular-season title and a solid showing in the conference tournament could be good enough, depending on how other teams do. For now, the Owls have simply been passed by other teams with more data points in their favor.

Cal State Fullerton is hanging around the edge of this discussion as well, but its weak conference schedule undermines its case. The Titans are 3-4 against the top 25 and 7-6 against the top 50 thanks to a strong nonconference schedule, but Fullerton doesn't have any top 50 opponents in the Big West.

Regional Hosts

SECURE TEAMS: The eight national seeds listed above; Kentucky, Rice, Cal State Fullerton, Purdue, North Carolina State

ON THE BUBBLE (IN): Stanford, Virginia, Arizona

ON THE BUBBLE (OUT): Arkansas, Texas A&M, Central Florida, Oregon State, Mississippi

One change from last week: Virginia replaces Arkansas as a host. The Cavaliers have been swept twice in the league by powers Florida State and North Carolina, but they have overcome those two weekends to climb to 14-10 in the ACC and No. 12 in the RPI. A road sweep at Miami two weeks ago was huge; UVa. is now 7-8 against the top 25 and 13-9 against the top 50. Virginia moves into hosting position even after an idle week thanks to Arkansas' home series loss to South Carolina. And Virginia's remaining schedule is very manageable, but will not hurt its RPI: it hosts Georgia Tech and then travels to Maryland.

Texas A&M (No. 17) and UCF (No. 20) still trail Arkansas (No. 11) in the RPI, and Arkansas has more top 25 wins (the Hogs are 5-10 in such games) than both of them combined (A&M is 1-6, UCF is 3-5). Arizona is No. 21 in the RPI, but its second-place standing in the strong Pac-12 and 6-5 record against the top 25 trump what the Hogs, Aggies and Knights have done.

So right now, we have four hosts apiece from the SEC, ACC and Pac-12, and one apiece from Conference USA, the Big 12, Big Ten and Big West.

At-large Bids

There are 30 automatic bids awarded to conference champions, and these 16 are safe bets to be one-bid leagues:

America East, Atlantic 10, Atlantic Sun, Colonial Athletic Association, Horizon, Ivy, Metro-Atlantic, Mid-American, Mid-Eastern, Mountain West, Northeast, Ohio Valley, Patriot, Summit, Sun Belt, Southwestern.

Cornell has already punched its ticket as the Ivy League representative.

The Mountain West is looking like it would wind up as a two-bid league if Texas Christian (up eight spots to No. 33 in the RPI this week) doesn't win the conference tournament; currently the Horned Frogs are tied with New Mexico atop the MWC standings.

CAA leader UNC Wilmington (No. 48) also has a chance at an at-large if it doesn't capture its automatic bid. Stetson (No. 53) and first-place South Carolina-Upstate (No. 71) are in the bubble discussion in the A-Sun, but right now neither team is in at-large position if it fails to capture its automatic bid (Stetson is still just 0-4 against the top 50 and three games out of first place in the standings, while Upstate's RPI will likely hold it back).

For this exercise, we will assume all 16 of those leagues receive one bid.

Below is a conference-by-conference look at which teams are on track to make the field in potential multi-bid leagues, and which teams are on the wrong side of the bubble through 12 weeks. We have five new teams in our field this week, an indication of just how fluid the bubble remains.

Here are the changes from last week's field of 64, in a nutshell:

IN: Indiana State, Washington, St. John's, Long Beach State, Tulane

OUT: Wake Forest, Oklahoma, Wichita State, Southern California, Auburn

Atlantic Coast Conference (8 total bids)

SAFELY IN: Florida State, North Carolina, North Carolina State, Virginia, Miami, Clemson

ON THE BUBBLE (IN): Georgia Tech, Virginia Tech

ON THE BUBBLE (OUT): Wake Forest, Maryland

One change from last week: Wake Forest falls out of our field of 64. The Demon Deacons were already on shaky ground after getting swept at Boston College last weekend, and they followed it up by splitting two midweek games against Elon. We weren't really comfortable making the ACC a nine-bid league last week, so we are dropping the ninth-place team in favor of some mid-major teams at near the top of their conference standings. Wake Forest is just 2-10 against the top 25 but is a more respectable 11-16 against the top 50. But it is a given that ACC teams have many more opportunities against good RPI teams than teams in the Big Ten or Big East, for example, and it isn't enough just to play in a good conference if you don't perform well in that conference. Wake Forest is 9-15 in the ACC, and it will be difficult to improve that record much with series remaining at Miami and vs. Clemson.

Virginia Tech has an even more difficult schedule (vs. N.C. State, at North Carolina), but the Hokies have more momentum (having won three of their last four series) and a better RPI than Wake. Georgia Tech must go to Virginia and then host Miami. It is easy to envision all three of those ACC bubble teams losing their final two series and winding up outside of regionals altogether, making the ACC a six-bid league. But with a lack of better bubble teams, we'll give the two Techs the benefit of the doubt for now.

Big 12 (3 bids)

SAFELY IN: Baylor, Texas A&M

ON THE BUBBLE (IN): Texas

ON THE BUBBLE (OUT): Oklahoma State, Oklahoma

One change from last week: Oklahoma falls out of our field of 64 after losing a series against Oklahoma State. At 13-8, the Cowboys are tied with Texas A&M and Texas for second place in the quagmire that is the Big 12 standings after Baylor, but OSU is still just No. 83 in the RPI and will take a hit this weekend with three games at Alcorn State. And the Cowboys are just 2-8 against the top 50. Oklahoma is a little better in the RPI (No. 67) and could climb back into the top 45 with a 5-2 finish against Baylor, TCU and Samford, but right now the Sooners sit in fifth place (10-10) in a lousy conference, and they are just 3-9 against the top 50. OU needs a very strong finish to overcome those blemishes.

Even Texas has slid onto the bubble after losing a series against Missouri. The Longhorns have tumbled to No. 51 in the RPI and are just 3-6 against the top 50. They have two games remaining against Texas Southern and three against Baylor. Their margin for error is slim, but for now they get the benefit of the doubt.

Big East (2 bids)

SAFELY IN: None

ON THE BUBBLE (IN): Louisville, St. John's

ON THE BUBBLE (OUT):  South Florida, Connecticut

One change from last week: St. John's enters our field of 64.

At 16-5, the Red Storm continues to lead the Big East by two games and has climbed 15 spots in the last two weeks in the RPI, up to No. 60. The resume still lacks quality wins (1-3 against the top 50), but the threshold is lower for a Northern team because of its inherent RPI disadvantages. The Johnnies travel to Louisville this weekend for a series that is critical to their at-large hopes. But even if they lose this weekend and still go on to win the Big East's regular-season title, St. John's will have a shot at an at-large berth. The Red Storm got in with an RPI in the 50s last year, and that was without a conference championship. The Johnnies have posted eight straight winning weekends.

Big South (1 bid)

SAFELY IN: Coastal Carolina

ON THE BUBBLE (IN): None

ON THE BUBBLE (OUT): Liberty, Radford

No change from last week.

Big Ten (2 bids)

SAFELY IN: Purdue

ON THE BUBBLE (IN): None

ON THE BUBBLE (OUT): Michigan State, Ohio State, Illinois

No change from last week.

The Spartans won a road series at Illinois to climb seven spots to No. 44 in the RPI. The Needs Report says MSU needs an 8-1 finish to land inside the top 45 at season's end, but the remaining schedule is favorable, with two home series left against Iowa and Penn State. Like St. John's, the Spartans lack quality wins (though they are 2-5 against the top 50, which is something, at least), but like St. John's, they don't need as many quality wins to get a berth as a Big Ten team. But unlike St. John's, the Spartans are not leading their conference (they trail first-place Purdue by four games). For now, that keeps them on the wrong side of our bubble.

The Buckeyes and Illini have RPIs in the 60s but aren't serious at-large contenders given their places in the Big Ten standings (OSU is in sixth place at 11-10, while Illinois is tied for seventh at 9-9).

Big West (2 bids)

SAFELY IN: Cal State Fullerton

ON THE BUBBLE (IN): Long Beach State

ON THE BUBBLE (OUT): UC Irvine, Cal Poly

One change from last week: Long Beach State moves into our field of 64. The Dirtbags have won seven straight weekend series to climb to 24-21 overall, finally giving them some breathing room (a team must finish above .500 to be eligible for an at-large spot). LBSU has inched up to No. 52 in the RPI and trails Fullerton by just a game in the Big West standings. The Beach is still just 1-7 against the top 25 and 4-11 against the top 50, but it has positive momentum, and its resume includes series wins against fringe at-large candidates California, Wichita State, Cal Poly and UC Irvine. That's good enough for us.

Irvine probably won't be able to recover from losing three straight series to Poly, Fullerton and Long Beach, but it has gotten hot over the last two weeks, sweeping home series against UC Riverside and UC Santa Barbara to climb back to No. 59 in the RPI. The remaining schedule features three crucial midweek games (two against San Diego, one against UCLA) that give the Anteaters a chance to remedy their 6-15 record against the top 100, but there is no margin for error. UCI needs an 11-1 finish to land inside the top 45. At least the 'Eaters have put themselves back in the discussion, but that's as far as it goes.

Conference USA (4 bids)

SAFELY IN: Rice, Central Florida, East Carolina

ON THE BUBBLE (IN): Tulane

ON THE BUBBLE (OUT): None

One change from last week: Tulane moves into our field of 64.

After getting swept at home by UCF, the Green Wave rescued its at-large hopes with back-to-back series wins at East Carolina and vs. Southern Miss (a sweep). Tulane is up 10 more spots to No. 49 in the RPI, but that ranking figures to go back down over the final two weeks, when the Green Wave faces Houston (No. 134) and Marshall (220). Tulane's 3-8 record against the top 25 and 4-10 record against the top 50 aren't exciting, but it is 3-0 against fellow bubble team Southeastern Louisiana, and it is sitting in fourth place in the No. 5 RPI conference. That's good enough for now, but as with a number of our other bubble teams, there is no margin for error down the stretch.

Great West (0 bids)

SAFELY IN: None

ON THE BUBBLE (IN): None

ON THE BUBBLE (OUT): Utah Valley

The Wolverines have put themselves on the radar with their 28-game winning streak, which could conceivably reach 37 (breaking the Division I record of 34) by the end of the regular season, because the remaining schedule features four games apiece against New York Tech (No. 295 in the RPI) and Northern Colorado (No. 279), plus one against Utah (No. 205). Unfortunately for UVU, those games won't help its own RPI (No. 61). The Great West does not get an automatic bid, but if Utah Valley can keep its winning streak going, it has at least a shot to snatch an at-large spot with an RPI outside of typical at-large range, thanks to the impressive nature of its winning streak. Utah Valley is 1-1 against Arizona and 1-1 against Arizona State, and it went 0-3 at Cal State Fullerton early in the season. Ultimately, we think the weight of the Great West's horrendous RPI (No. 30) will drag the Wolverines down too far for an at-large spot. But stay tuned.

Independents (1 bid)

SAFELY IN: Dallas Baptist

ON THE BUBBLE (IN): None

ON THE BUBBLE (OUT): None

No change from last week. DBU reversed its downward momentum with a 5-0 week, taking two midweek games from Texas-Arlington and sweeping a weekend series against Evansville. The Patriots are sitting pretty at No. 22 in the RPI, and a 4-4 finish would land it inside the top 32 at season's end. Move Dallas Baptist back into the SAFELY IN category.

Missouri Valley (2 bids)

SAFELY IN: Missouri State

ON THE BUBBLE (IN): Indiana State

ON THE BUBBLE (OUT): Wichita State, llinois State

One change from last week: Indiana State replaces Wichita state in our field, reversing a change we made last week. The Sycamores have posted 11 consecutive winning weekends since getting swept at Southeastern Louisiana, including a series win against Dallas Baptist three weeks ago and another big series win against Wichita State this past weekend. Because Indiana State has played 18 games against teams outside the top 150, its RPI is still just No. 56, but it is 2-1 against the top 25, 4-2 against the top 50 and 9-7 against the top 100. That compares favorably with other bubble teams.

Pacific-12 (6 bids)

SAFELY IN: UCLA, Oregon, Arizona, Stanford, Oregon State

ON THE BUBBLE (IN): Washington

ON THE BUBBLE (OUT): California, Washington State

One change from last week: Washington replaces Southern California in our field of 64.

USC is ice cold, with a 4-11 mark in its last 15 games and an RPI that has fallen to No. 73. After getting swept at home by Washington this weekend, USC is no longer even on our bubble. The Huskies, meanwhile, are up to No. 42 in the RPI, have a respectable 4-5 record against the top 25, a 13-15 mark against the top 50 and positive momentum. They're in, seeking their first regional bid since 2004, Tim Lincecum's freshman season.

Southeastern Conference (8 bids)

SAFELY IN: Kentucky, Louisiana State, Florida, South Carolina, Arkansas, Mississippi State, Mississippi

ON THE BUBBLE (IN): Georgia

ON THE BUBBLE (OUT): Auburn, Vanderbilt

One change from last week: Auburn falls back out of our field of 64 after getting swept by Georgia. Auburn's yo-yo RPI has gone from No. 62 to No. 46 back to No. 64 in the last three weeks. The Tigers have lost four of their last five series to fall to 25-22 overall and 10-14 in the SEC, and the remaining schedule is very difficult (at Arkansas, vs. Florida). Those last two weeks present an opportunity to rescue its at-large hopes, but don't count on it.

The sweep puts Georgia on better footing, but it is still on the bubble at No. 41 in the RPI. UGa.'s 7-13 record against the top 50 is respectable, and a home series win against South Carolina this weekend would move the Bulldogs into the "secure" category.

Vanderbilt has climbed mostly out of its early hole to get within one game of .500 overall (23-24). Series wins over the last four weeks against Auburn, Kentucky and Tennessee have helped the Commodores climb to No. 47 in the RPI and 11-13 in the SEC, but the .500 mark is still Vandy's biggest obstacle. Vandy has seven challenging games left (vs. Louisville, three at LSU, three vs. Ole Miss). If it goes 4-3 in those games, it will finish right at .500 overall, which means it would need at least three wins in Hoover to finish above .500 and be eligible for an at-large. If Vandy does that, it should get in, but that's a tall order.

Southern Conference (3 bids)

SAFELY IN: Appalachian State, College of Charleston

ON THE BUBBLE (IN): Elon

ON THE BUBBLE (OUT): Samford

No change from last week. Elon's second-half sag continued with a series loss to Western Carolina at home this weekend, and the Phoenix is on very precarious ground. But Elon is still 17-10 in the SoCon with series wins over the three teams ahead of it in the standings (ASU, CofC, Samford). Its 0-10 record against the top 25 is ugly, but its 6-14 record against the top 50 is better, and its 17-18 mark against the top 100 is solid. Elon remains in our field by the skin of its teeth.

Southland Conference (3 bids)

SAFELY IN: None

ON THE BUBBLE (IN): Sam Houston State, Southeastern Louisiana, Texas State

ON THE BUBBLE (OUT): Texas-Arlington

No change from last week. Texas State needs a strong finish (against UTSA and Northwestern State) to boost its place in the Southland standings; it is in fourth place at 15-12, five games behind SHSU. Assuming the Bobcats do finish strong against their manageable schedule, they remain in the at-large mix thanks to a No. 54 RPI, a 3-2 mark against the top 25 and a 6-5 record against the top 50.

Southeastern Louisiana is No. 55 in the RPI, 2-4 against the top 50, but 9-0 against teams 51-100. Sweeps of Texas State, UT Arlington and Indiana State that prop up the Lions' case. SELA is 0-3 against Tulane but 2-0 against Mississippi State. A series win at SHSU this weekend would put the Lions in very good shape, but a series loss wouldn't necessarily torpedo them.

The Bearkats fall onto the bubble after losing a series at UTA, causing them to drop to No. 48 in the RPI. But their perch atop the Southland standings and overall body of work is enough to keep them in our field fairly comfortably.

West Coast Conference (3 bids)

SAFELY IN: San Diego

ON THE BUBBLE (IN): Pepperdine, Gonzaga

ON THE BUBBLE (OUT): Portland

No change from last week. Gonzaga was swept in two midweek games by Oregon last week and has fallen to No. 36 in the RPI. The Zags are just 1-6 against the top 25, but is 4-1 against teams 26-50 and 14-6 against teams 51-100. A home series against Arizona State gives Gonzaga a chance to boost its case this weekend. The Zags have lost eight of their last 11, so they can ill afford to let their negative momentum continue. But for now, their resume is still enough to snatch an at-large spot.

Western Athletic Conference (1 bid)

SAFELY IN: New Mexico State

ON THE BUBBLE (IN): None

ON THE BUBBLE (OUT): Hawaii, Nevada

No change from last week. The Aggies are still 27th in the RPI even after getting swept by Hawaii, keeping them in good shape for an at-large bid. A 6-2 finish against a manageable schedule would land NMSU in the top 32 by season's end.

The sweep thrust Hawaii into the at-large mix. The Rainbows lead the WAC by a game over the Aggies and Wolf Pack and are up to No. 65 in the RPI. Hawaii's 7-8 record against the top 50 is respectable, but it needs to finish very strong against Sacramento State and Nevada to continue to keep its RPI from falling out of bubble range. The Rainbows own a series win at Wichita State but were swept in a four-game set by Gonzaga, and did lose a series at Louisiana Tech last week.