The first 10 weeks of the college basketball season has given us a large-enough sample size to begin formulating overarching opinions on the state of the sport. This season has been a revolving door for upsets -- particularly with No. 1-ranked teams, with six different programs holding the top spot. Still, the cream of the crop has slowly risen to the top of the landscape with Gonzaga. Duke, Kansas and others. On the opposite end of the spectrum, others have dive-bombed comparative to preseason expectations.

Among the big surprises are the only two undefeated teams in the sport entering the week: San Diego State and Auburn. Combined, they have a 28-0 record -- and that's despite SDSU entering the season unranked. Both are top-10 teams as of this week as conference play ramps up.

What other teams have been the biggest pleasant surprises this season? Let's dive in.

1. San Diego State

There are only two undefeated teams left in college basketball, and San Diego State -- at 15-0 -- is one of them. There are plenty of surprising teams in college basketball this season, but this Aztecs team takes the cake. They entered the season with 100-1 odds to win it all and can be found at 40-1 at most places now.

San Diego State's meteoric rise can be credited largely with its structure defensively. Through 15 games, it is allowing 87.7 points per 100 possessions -- good for No. 12 nationally in adjusted efficiency, per KenPom -- and rates in the top-15 in 3-point defense and field goal percentage defense. Former Washington State guard Malachi Flynn is leading the team in scoring, assists and steals, and gives SDSU star power at guard it has been lacking over the last few seasons.

2. Auburn

If you haven't learned your lesson by now, let this get through your thick skull: Bruce Pearl can absolutely, positively coach. Like, really, really coach. He lost his top three scorers from last year's Final Four team that won 30 games and has managed a flawless 13-0 start to the year -- its best start to a season in more than 21 years. The Tigers still haven't faced a ranked opponent, but they've beat everyone they've lined up against. With a balance of young talent and experience best explained by its top two scorers -- senior Samir Doughty and freshman Isaac Okoro -- this team has the depth and talent to win the SEC for the second time in three years.

3. Wichita State

The Shockers took a step back last season, winning only 22 games with a young and inexperienced roster. That allowed Gregg Marshall to groom his club for a step forward this season, and it's been a bigger leap than expected. They're 13-1 on the season with two wins over Big 12 programs, a win over an SEC program and a home win over VCU. Things are going shockingly well. They're in line to get back to the NCAA Tournament for the second time since arriving in the AAC and should be considered, at the very least, a co-favorite to win the conference outright.

4. Butler

Butler was picked eighth in the Big East preseason coaches poll. Eighth! In a 10-team league! Right now, there aren't seven better teams in college basketball better than Butler, let alone in the Big East. The Bulldogs are 14-1 with six top-55 KenPom wins -- Florida, Stanford, Mizzou, Purdue, Creighton, among them. They're looking like the class of the conference with each passing day. What LaVall Jordan has done with a roster many people overlooked and underestimated is nothing short of Coach of the Year worthy.

5. Florida State

Leonard Hamilton is surprising folks again with a team better than anyone anticipated. When will we ever learn? Hamilton's taken FSU to two consecutive Sweet 16s, an Elite Eight and three straight years as a tourney participant with a single digit seed. The Seminoles are 13-2 on the year with a road win over Louisville last weekend the latest feather in their cap. Maybe next year we'll give FSU its proper due in the preseason.

6. Penn State

Some folks may have disagreed with Penn State's decision to bring back coach Pat Chambers after a 14-18 campaign last season. Those folks, as this season has proved, were wrong. Continuity matters a ton. And Chambers still has the juice to compete in the Big Ten. He has his Nittany Lions sitting at 12-2 on the season and 2-1 in Big Ten play, with wins over Maryland and Iowa in recent weeks. This is a top-3 team in the Big Ten, a remarkable turnaround for a team that went 7-13 in league play a year ago.

7. Arkansas

I bought in to first-year coach Eric Musselman having success in 2019-20 before he was even having success in 2019-20. In August, I wrote this of the Razorbacks: 

Even after losing Daniel Gafford to the NBA, Arkansas is set up for success in 2019-20. New coach Eric Musselman has graduate transfer Jimmy Whitt Jr. to add to a talented trio of young guards in Isaiah Joe, Mason Jones and Jalen Harris, the former of which could be a first-round talent as early as 2020. The Hogs have a chance to go from 8-10 in conference play to 11-7 or better if things come together correctly. 

I'm not saying I'm a soothsayer, but guess what KenPom.com currently projects Arkansas' SEC record this season? You guessed it: 11-7. Musselman's muscled his Razorbacks to relevancy in a hurry in Fayetteville. College basketball's better when this program is winning.