Last week, the number-one team in the nation fell for the fourth time this season, and 17 of the Associated Press' top 25 teams changed rankings by at least three spots from the prior week.

Having trouble keeping up? You're not alone.

We're going to profile some of the notable risers and fallers in the AP Top 25 and, with the help of numberFire's college basketball team metrics, look to make some sense of this seemingly "non-sensical" season.

Bull Market

West Virginia
Current Rank: 6th
Last Week: 11th
Rise/Fall: +5

Bob Huggins' Mountaineers had the unenviable task of going back-to-back against the top-two teams in the nation last week, and they seized the opportunity in a big way. WVU knocked off top-ranked Kansas in an 11-point home win before falling at Oklahoma (the new number-one team in the nation) by just two points. West Virginia's eye-opening week vaulted them into the AP’s top 10 and up to fourth in our power rankings. At 15-2, and fifth in RPI, West Virginia is knocking on the door of a 1 seed in numberFire's Bracketology.

Iowa
Current Rank: 9th
Last Week: 16th
Rise/Fall: +7

Iowa's 5-0 start in the Big Ten includes two wins in 17 days against a highly-respected Michigan State team (10th in nERD). An earlier win at Purdue and Sunday's win at Michigan has Iowa up to sixth in the nERD power rankings, good for a projected 3 seed in numberFire’s Bracketology.

North Carolina
Current Rank: 2nd
Last Week: 5th
Rise/Fall: +3

UNC had a ho-hum week, with just a win against NC State to their credit. But as winners of nine straight, including a 5-0 start in the ACC, they have been one of the biggest beneficiaries of the volatility at the top of the AP rankings. nERD's seventh-ranked team won't be tested again until February 1st at Louisville, so until then, it's all about avoiding bad losses as the Tar Heels make a push for the top seed line.

Baylor
Current Rank: 13th
Last Week: 22nd
Rise/Fall: +9

No team ascended further in this week's rankings than the Bears, who have won four straight in America's toughest conference, including a win at Texas Tech. Baylor is numberFire’s 11th-ranked offense in terms of efficiency, boasts wins over two top 25 nERD teams (Vanderbilt and Iowa State), and lost all three of their games to top-30 nERD teams (Kansas, Texas A&M, and Oregon). We currently have the Bears projected as a 6 seed, which indicates that their spot at 13th in the country might have more to do with everyone else around them losing than it does with their own resume. A home date with Oklahoma this Saturday will be a great litmus test for Baylor and the depth of the Big 12.

Bear Market

Duke
Current Rank: 20th
Last Week: 9th
Rise/Fall: -11

Duke is far from the only quality team that has lost lately to surprise ACC giant killer Clemson, but their second loss of the week, to Notre Dame, marked Duke's first home defeat of the season. Shortly after the release of this week’s rankings, which had Duke fall out of the top 10 all the way to 20th, Syracuse handed Coach K and company their second home loss of the season. The setback against the Orange marked the first time Duke has dropped three straight games since 2007. Despite the recent slide, Duke boasts strong computer numbers (top 15 in RPI and strength of schedule, at the time of the Syracuse game). But a defense that currently ranks outside numberFire’s top 100 in efficiency has to improve quickly if Duke plans on grabbing some much-needed signature wins during a 13-day stretch in February that has them home for Louisville and Virginia, before traveling to face UNC and Louisville.

Michigan State
Current Rank: 11th
Last Week: 4th
Rise/Fall: -7

The Spartans have dropped their last two, including Sunday’s loss at Wisconsin, a team that started 1-4 in Big Ten play. Michigan State’s only other two losses have come to Iowa, a top 10 AP and nERD team, so their resume remains one of the strongest in the country. Tom Izzo’s squad is inside the top 15 in numberFire’s Offensive and Defensive Efficiency ratings, as well as RPI. Saturday’s home date with Maryland (17th in nERD) should serve as a showcase for some of the top talent in college basketball.

Miami (FL)
Current Rank: 15th
Last Week: 8th
Rise/Fall: -7

Like the last two teams we’ve discussed, Miami fell twice last week, both on the road. Virginia beat Miami for the only win they have earned in their last four games, and Clemson made Miami their latest victim on Saturday. The Hurricanes, ranked 12th in nERD, have a good shot at finding their feet against a decidedly-lighter schedule this week (at Boston College, home for Wake Forest) before hosting Duke next Monday.

South Carolina
Current Rank: 24th
Last Week: 19th
Rise/Fall: -5

In his fourth season in Columbia, Frank Martin has turned the Gamecocks into one of the nation’s pleasant surprises. But South Carolina finally stubbed their collective toe last week, losing by 23 at Alabama (ranked 91st in nERD). The Gamecocks cracked the AP rankings four weeks ago, rising as high as 19th in the country after a 15-0 start. But the blowout loss could cause the skeptics to question loudly whether South Carolina is really NCAA Tournament material. numberFire projects Martin’s group as a 9 seed, with an 80 percent chance of making the Big Dance. But a 103rd-ranked strength of schedule, a consistency rating in the bottom quarter of the nation, and just one win against a nERD top 50 team so far means there’s plenty of work to be done to get South Carolina to their first NCAA Tournament since 2004.