During the NFL draft, more than a few pundits pointed out the absence of selections from Ohio State. The Buckeyes ended up with a respectable five picks -- best in the Big Ten -- but none in the first round and just two in the first three rounds.

While that initially seemed like a slight on the 2014 national champions, what it actually meant was college football should have a unanimous pick as 2015 preseason No. 1.

The Buckeyes welcome back 15 position player starters as well as their kicker and punter from the team that shocked Alabama and Oregon in the College Football Playoff. But it's not just about starters coming back. It's quality. Everyone knows that Ohio State has three proven, A-list quarterbacks who have won big games as starters, but it also has five players that Todd McShay already is projecting as 2016 first-round picks, topped by All-America defensive lineman Joey Bosa.

So this is an experienced team that wasn't hit by an NFL talent drain after it won a national title.

Ah, assessing the annual talent drain. It's the inexact science we use in college football to evaluate teams and conferences in the preseason in order to speculate on how good the former and how deep the latter might be.

Counting returning starters is a popular way to measure a team's or conference's potential in the preseason, but it also has limited scope. Vanderbilt's 18 returning starters won't scare anyone, nor will Wake Forest's 16.

TCU's 14 returning starters (we're using returning starter numbers compiled by Phil Steele here) from a 12-1 team, however, will raise a few eyebrows and likely provide a consensus No. 2, while Alabama doesn't stand to receive too much of a demotion with just 11 starters back, nor will Oregon with 12.

But how about we explore this at more macro level, evaluating the talent retention/drain by conference? After all, you are probably well-versed on who is coming back on your team. What about the depth of your conference and other Power 5 conferences competing for spots in the CFP?

Pac-12

Returning starters (13.9): 7.6 offense; 6.3 defense; 7/12 QBs

First-team all-conference returning (6*): 3 offense; 3 defense

NFL draft (39): 3.3 picks per team; 9 first-round picks; 25 picks in first three rounds

Analysis: The Pac-12 ties the Big 12 for highest average per team of returning starters, and the conference is again expected to be extremely deep in 2015. As many as seven teams are candidates for preseason rankings, and teams in the bottom third, such as California and Colorado, look -- on paper -- to be much improved. There are, however, some red flags. The conference has the lowest percentage of returning starting QBs, with potential top-10 teams Oregon and UCLA both uncertain behind center. The conference also lost a lot of star power -- see a conference-record nine first-round NFL draft picks and a Power 5-leading 25 selections in the first three rounds.

*This number includes Oregon TE Pharaoh Brown, who is injured and questionable for the 2015 season.

Big 12

Returning starters (13.9): 7.1 offense; 6.8 defense; 7/10 QBs

First-team all-conference returning (13): 7 offense; 6 defense

NFL draft (25): 2.5 picks per team; 2 first-round picks; 7 picks in first three rounds

Analysis: While there was plenty of handwringing about the Big 12's lackluster NFL draft, some of these numbers hint that the conference could be on the uptick this fall. While the returning starter average only ties the Pac-12, the 13 first-team All-Big 12 players returning -- by far the most among the Power 5 -- shows that many of the best players from last year will be back in 2015. The Big 12 also welcomes back the most defensive starters per team and returns seven of 10 starting quarterbacks. TCU and Baylor should lead the charge, but Texas Tech and Oklahoma State, with 17 and 16 starters back respectively, also are teams to watch.

SEC

Returning starters (13.6): 6.9 offense; 6.7 defense; 9/14 QBs

First-team all-conference returning (5): 4 offense; 1 defense

NFL draft (54): 3.9 picks per team; 7 first-round picks; 22 picks in first three rounds.

Analysis: The SEC has long dominated the NFL draft. That and its nine BCS national championship form a strong foundation for why the conference is widely viewed as the nation's best. The SEC, however, hasn't won a national title over the past two seasons, and this most recent draft is far from its most impressive, though it still ended up with the most overall selections. In 2013, it yielded a stunning 63 draft picks, including 32 in the first three rounds. It led the nation with 49 selections in 2014, including 11 in the first round. Yet the slight downtick in the SEC's 2014 season and draft results this spring might actually not indicate the conference is losing ground. It might presage a big return to power this fall, see a high number of returning starters per team -- with Tennessee, Ole Miss, Arkansas, LSU and Texas A&M leading the charge -- and a solid nine returning starting quarterbacks.

Big Ten

Returning starters (13.1): 6.6 offense; 6.5 defense; 10/14 QBs

First-team all-conference returning (7): 3 offense; 4 defense

NFL draft (35): 2.5 picks per team; 3 first-round picks; 15 picks in first three rounds

Analysis: The draft numbers are down, and they aren't offset by a bevy of returning starters. Conclusion: The overall talent in the Big Ten is down -- I know; Not the first time that's been typed -- even as Ohio State makes a superpower surge. What that could mean is the Buckeyes' path to another College Football Playoff appearance might not be that taxing. On the other hand, the Big Ten is coming off a strong showing in the bowl season, going 5-5 despite being underdogs in every game, with big wins coming from its top three teams: Ohio State, Michigan State and Wisconsin. And having 10 of 14 quarterbacks returning is a reason for optimism. Still, after Ohio State and Michigan State, there's plenty of uncertainty.

ACC

Returning starters (12.5): 6.6 offense; 5.9 defense; 11/14 QBs

First-team all-conference returning (5): 3 offense; 2 defense

NFL draft (47): 3.4 picks per team; 9 first-round picks; 20 picks in first three rounds

Analysis: So the ACC loses the second highest number of NFL draft picks per team, including nine from the first round and 20 from the first three rounds, and it has the fewest returning starters per team. Hmm. Just five first-team all-conference players return, and two of the three offensive players are from Pittsburgh. Double hmm. And none of the ACC's top five teams from 2014 -- Florida State, Clemson, Georgia Tech, Louisville and Duke -- have more than 13 returning starters. Triple hmm. Grounds for optimism? Well, 11 of 14 starting quarterbacks returning is the highest percentage among Power 5 conferences. And games aren't won or lost on paper.