ASSUME THE POSITION 2014: DEFENSIVE TACKLE

Assume the Position is our offseason guide to the Iowa Hawkeyes football depth chart. The math is difficult, so take it from us: As time moves on, we'll know more. That's why we rank the positions from most certain to least certain.

Previously: Quarterback

Today: Defensive tackle

Two years ago, the defensive line depth chart was decimated by graduation, attrition, and poor recruiting.  Iowa had struck out with a string of defensive tackles, forcing the Hawkeyes to use erstwhile role players like Steve Bigach inside.  The results were disastrous for the Iowa defense, and the Iowa defense's problems was disastrous for Iowa football.

After just 24 months under the tutelage of Iowa's best talent developer, Iowa's defensive tackle depth chart is loaded like the Velvet Underground.  There are five players capable of starting for most of the Big Ten's teams, with two massive anchors in the middle of the line returning for their final campaigns.  End is still a bit of a mess, but tackle has gone from an unquestioned weakness to a bona fide strength.  Reese Morgan is really good at his job.

Crazy Carl

Carl Davis (#71, Senior (RS), 6'5, 315 lbs., Stevenson HS (Detroit))

Some real basics here: Iowa plays almost exclusively in a four-man defensive front, with two defensive tackles.  Each defensive tackle (and, for that matter, each defensive end) has responsibility for one "gap" in the offensive front.  Iowa typically runs a "4-3 under" in which the strongside linebacker (Christian Kirksey in last year's defense) is lined up over the tight end or slot receiver.  In that set, Iowa uses a "1-technique" tackle and a "3-technique" tackle.  The 1-technique tackle lines up between the center and guard, and is expected to draw a double team to free up other players to get in the backfield.  The 3-technique tackle is the rush tackle, lined up between the guard and tackle on the opposite side of the 1-technique, and should be one-on-one with an offensive lineman if everyone does their jobs.

For a better explanation, I'm going to crib from the always excellent Chris Brown of Grantland and Smart Football (you'll probably notice over the coming weeks that I read Brown's book, The Essential Smart Football, over vacation last month and learned a lot):

"Gap" refers to the area between offensive linemen.  A one-gap technique is just what it sounds like: the defensive lineman lines up in front of the gap he is responsible for, and his job is to attack and control it.  If nothing else, a defender must not allow a runner to go through his gap.  While defensive linemen attack their gaps, the linebackers behind them are responsible for their own gaps.  These are the defense's "run fits" meaning how they fit into an offense's blocking scheme to take away the running game.

...

The 4-3 has been around for a long time.  Legendary Dallas Cowboys coach Tom Landry even had his own variant named after him, the Landry 4-3 Flex, but [Jimmy] Johnson concocted his version as anti-wishbone medicine.  Instead of telling defensive linemen to two-gap and watching them get fooled by the option on every play, he switched entirely to a one-gap system.  Johnson simplified things for them by giving them one job and telling them to attack.  We still see this principle now; Detroit Lions head coach Jim Schwartz, himself a former 4-3 defensive line coach, only slightly exaggerated when he said his playbook for defensive tackles consists of two words: "Kick butt."

Iowa has always thrived on this kind of setup and philosophy, the oversized 1-tech defensive tackle (think Matt Kroul) paired with an undersized, athletic 3-tech (think Mitch King) who could blow up the pocket and disrupt the interior running game.  At the very least, those two players would control their assigned gaps through technique, leverage, and tenacity, and let the linebackers clean up.  At best, they'd do the cleaning themselves.

For years, we assumed Davis was destined for the 1-tech spot, a 300-pound gap-filling marauder who could clear the way for a smaller tackle to make plays.  It wasn't until halfway through last year that we realized we had it completely wrong.  Davis carries his 315 pounds so well -- it's all just arms as wide as your thighs and thighs as wide as your torso -- and is so explosive off the snap that he's better used as the undersized guy.

I'm going to stop for a second and let that sink in: The 6'5, 315-lb. tackle is the undersized, athletic one.  Your argument is invalid.

The coaches caught this much earlier -- spring practice, if not sooner -- and when they did, Davis became a monster.  He finished the season with a second-team all-conference selection from the Big Ten's coaches, and his 42 tackles and 4.5 TFL were both crucial.  But Davis did something even more important: He gave Phil Parker versatility.  Davis' size meant he could certainly hold up against a double team, so stunting Carl into a double team and allowing Trinca-Pasat or a defensive end to come free behind him became one of Iowa's most effective defensive plays.  And numbers or not, Davis was one of Iowa's most effective defenders.  The NFL falls all over itself for guys like him, and payday beckons.

Fat Jeff Tweedy

Louis Trinca-Pasat (#90, Senior (RS), 6'3, 290 lbs., Lane Tech (Chicago))

The final play of Iowa-Northwestern from last October is really all you need to know about Louis Trinca-Pasat.

LTP slips over a stunt with Carl Davis (see above) and gets a free shot at Kain Colter.  The Northwestern quarterback, as he had all day, sidestepped the pressure and tried to roll right.  But Trinca-Pasat got back to his feet, resumed his pursuit, and caught Colter five yards downfield and at least fifteen yards from where he initially fell for his first and only sack of the season.  It was an amazing hustle play in a crucial spot, and it wasn't the only time last year.

Trinca-Pasat went from a relative unknown to the team's most consistent defensive lineman in 2012.  He went from Iowa's best lineman to one of the conference's best tackles in 2013.  LTP was honorable mention all-conference last season, and probably deserved better.  He started every game for Iowa, shirking the injury bug that had nagged him throughout his career, and racked up 38 tackles and 8 tackles for loss.  Oh, and one sack that gives us hope that the interior asskickers so important to Iowa's success over the last 15 years are back.  We expect one hell of a final act in 2014.

The Third Man

Darian Cooper (#97, Junior (RS), 6'2, 285 lbs., DeMatha Catholic (Elkridge, Md.))

The emergence of Davis and LTP as every-down defensive tackles limited the use of a rotation in the interior defensive line last season.  The big loser in that was Cooper, who played less and recorded fewer tackles than he had as a sophomore.  It's no knock on Cooper as a player, mind you.  It's just that the Hawkeyes suddenly and unexpectedly stumbled into a pair of world-wreckers at the same position he plays.  Cooper has the build to play either tackle position (though he's likely destined for the 3-tech opposite the massive Jaleel Johnson in 2015), and will probably be the next man in if either Davis or Trinca-Pasat miss time this year.  But it's probably another year of waiting for a guy who has been absurdly patient so far.

While You Wait for the Others

Jaleel Johnson (#67, Sophomore (RS), 6'4, 310 lbs., Montini Catholic (Lombard, Ill.))

Where Carl Davis is a sneaky 300 pounds, Johnson looks like precisely the block-absorbing giant that his measurements suggest; if anything, that 310 pounds is light.  If spring was any indication, he's having the same problems that Davis did: A career spent being the biggest guy on the field by 40 pounds didn't demand he learn leverage or technique, and he now plays too high against interior linemen who are just as big as he is.  He won't see significant time until that problem is resolved, but if Davis' progression and Reese Morgan's track record are any indication, that should come soon enough for him to contribute significantly in 2015.

Faith Ekakitie (#56, Sophomore (RS), 6'3, 285 lbs., Lake Forest (Ill.) Academy/Brampton, Ontario)

Iowa toyed with moving Ekakitie to end last spring, mostly because the coaches desperately needed depth on the edge and Ekakitie looked fast enough to be serviceable as a strongside end.  The change never really took, though; Ekakitie was left off the depth chart for the entire season, and he was back at tackle this spring.  With the logjam ahead of him, a later move to end can't be ruled completely out, but he might be stuck behind a line of talented linemen this year and as third man next season.

Wil Rathjen (#87, Senior (RS), 6'3, 280 lbs., Durant (Iowa) HS/Iowa Central C.C.)

Rathjen walked on in 2012 after a solid two-year career at Iowa Central, and he checks all the Ferentz boxes -- Iowa kid, overlooked because his high school team wasn't very good, former heavyweight wrestler, etc. -- but he really has no chance in this depth chart.  Morgan praised his leadership ability and work on the scout team this spring, and he'll probably end his career at Iowa with those same roles.

Nathan Bazata (#99, Freshman (RS), 6'2, 285 lbs., Howells-Dodge HS (Howells, Neb.))

Bazata is a classic Morgan project: A three-star prospect out of a small Nebraska school whose only other offer was South Dakota State.  He came in at 290 pounds, and the decrease in weight is a telltale sign of a Chris Doyle reimaging.  That's a two-year process at the least, which is fine because he is not needed any time soon.

Brant Gressel (#72, Freshman (RS), 6'2, 280 lbs., Centerville (Ohio) HS))

Gressel was more highly-touted than his classmate coming out of high school, with the likes of Louisville, West Virginia, NC State and Cincinnati (and B1Gs like Minnesota and Indiana) in hot pursuit.  But like Bazata, he's buried on this list and probably needs another season of weights and technique before getting any serious consideration.