It's impossible to pick a perfect NCAA bracket without reaching for more than a few bold upsets. Mathematically, however, the surest way to the most accurate bracket is by picking the teams with the higher seeds. Thus, unless you're in Warren Buffett's billion dollar pool, you're best served choosing upsets on which you're fairly certain.

For those with hunches looking for second-party confirmation, below are the most common first round upset picks on CBS Sports.

1. #9 Pittsburg, 68 percent

2. #9 Oklahoma State, 63

3. #10 Arizona State, 40

4. #10 St. Joseph's, 36

5. #10 Stanford, 34

6. #12 Harvard, 34

7. #9 George Washington, 32

8. #11 Nebraska, 28

9. #11 Iowa/Tennessee, 27

10. #12 Stephen F. Austin, 26

Funny, those 6-11 games are always a tough call. Conversely, the 5-12 games are seemingly more upset-heavy, which is maybe why #12 Harvard (versus Cincinnati) is the sixth most popular upset pick ahead of the first #11 seed, Nebraska (versus Baylor). Not surprisingly, most fans prefer Oklahoma State and their controversial two-guard, Marcus Smart, over Gonzaga. I would have thought the Cowboys the more popular pick over Pittsburg, but Colorado's less than impressive record and relatively weak conference probably hurt their standing among fans.

At number 10, Stephen F. Austin is getting love because of their gaudy record (31-2, 18-0) and their opponent's status as #2 in a mid-major conference (VCU).

Not counting 9 seeds, below are my top five favorite upset picks:

1. Iowa (if they win) over UMass: Iowa has played tough all year long

2. Dayton over Ohio State: Ohio vs. Ohio rivalry could propel Dayton

3. New Mexico State over San Diego State: Read NM State has a player 7-foot-5

4. N.C. State over Saint Louis: T.J. Warren over slumping mid-major, easy pick

5. Harvard over Cincinnati: Heard good things about Harvard