Different teams will define which safety is "free" and which is "strong" by different criteria but for fun, I'll rank the guys that played what I would define as the "free safety" position in the Big 12 last year.
1. Derrick Kindred, TCUKindred was far and away the best free safety in the Big 12 last year, often playing in an aggro-quarters scheme that put a lot on his plate which he held down fairly well. I wouldn't call him an elite FS, though he might have made an exceptional weak safety for the Frogs, but this position was awful in the Big 12 last year.
Team defensive S&P rank: 59th
2. Ahmad Thomas, OklahomaI wouldn't say Thomas was particularly exceptional either, but he was positionally sound, made tackles, and managed to pick off three passes and break up three others. Thomas benefitted tremendously from playing with good corners and other safeties who could play man coverage as well as a pass rush that all served to make his job easier.
He'll have the former again next year but if he doesn't get a good pass rush in front of him don't be shocked to see him have some tough moments in 2016.
Team defensive S&P rank: 16th
3. Dravon Henry, West VirginiaThis one is tough as we are choosing from a lot of flawed candidates at this point. Henry was good at playing over the top and preventing anything terrible from happening to West Virginia down the seams but he lacked the range to have a lot of impact in the run game or breaking up passes.
Team defensive S&P rank: 28th
4. Tre Flowers, Oklahoma StateFlowers finished the year with 83 tackles, two INTs, and eight pass break-ups while manning an "aggro-quarters" FS role in the OSU defense. Of course, the Cowboys weren't that great on defense this year despite having a good pass-rush but Flowers held up reasonably well.
Team defensive S&P rank: 64th
5. Dylan Haines, TexasFrom here on out you're looking at pretty flawed players. I'll say this for Haines, he finished the year with five interceptions and three other break-ups because he's very positionally sound and knows how to make the most of the talent around him. He's too athletically limited to excel here though and is only useful as a stopgap so far as his teammates can protect him, much like Ahmad Thomas.
Team defensive S&P rank: 66th
6. Nate Jackson, Kansas StateThe Wildcats moved Jackson to FS when Dante Barnett went down and it grievously hurt their defense. Jackson was a useful utility man for the Wildcats and actually played well when moved to the nickel in the bowl game so that speed-challenged FS Sean Newlan could step in, this is simply a demanding position.
He did break up six passes and was solid in coverage, he simply wasn't able to be a great alley-runner and run game eraser for the 'Cats, which their "bend don't break" strategies really need.
Team defensive S&P rank: 83rd
7. Qujuan Floyd, Iowa StateFloyd is one of many guys on this list who'd probably be valuable DBs if not having to play in the extreme spacing of the FS position against good spread offenses. Iowa State would often move CB Jomal Wiltz to this position at times to have a better coverage player available and Wiltz was actually fairly solid, at least in coverage.
Team defensive S&P rank: 68th
8. Fish Smithson, Kansas
Ditto to Floyd, a good tackler and valuable DB who was miscast as a free safety where he was forced to operate in too much space. Smithson finished the year though with 111 tackles, two INTs, and three break-ups.
Team defensive S&P rank: 123
9. Chance Waz, Baylor
The Bears did what they could to keep Waz safe and in deep 1/2 zones or even 1/4 zones with Orion Stewart rolled over from the boundary or Blanchard playing more conservatively to help him bracket slots. Despite being shielded whenever possible, Waz failed to make any INTs and broke up only three passes. He's a solid athlete who can tackle and might become a good player in the future but he limited what Baylor could do in 2015.
Team defensive S&P rank: 65th
10. Keenon WardTexas Tech was horrendous in the middle of the field last season. Horrendous. They tried Ward, Nelson, and Gaines here but there was just nothing doing. If not for Pete Robertson, some decent DL, and solid corner play from Nelson, Madison, and Bethel this team would have ranked dead last nationally.
Watch their tape though and you'll see them get beat up front often and then you'll see a lot of mistakes that become disasters.
Team defensive S&P rank: 121st
Lots of low S&P ranks for the Big 12 defenses last year, no? That's partly because FS play was poor. With Dante Barnett back for K-State, young blood emerging at Texas, and some of the more promising guys listed above return, things should improve in 2016.