Head coaches are like quarterbacks. They get too much credit and too much blame.

Assistant coaches are like nose tackles. They don't get nearly enough credit despite playing vital roles.

Today, we'll change it up and give some recognition to Big Ten assistant coaches who did exemplary jobs with their position groups or, in some cases, units in 2012. Each of these coaches fostered improvement this season. Some took units in bad shape and made them better. Others took units in decent shape and made them very good. Some entered the season with skeptics and quieted them.

We came up with 13 assistants who deserve recognition. Yes, we realize we're leaving out some quality folks, but we had to cap it somewhere and wanted to spread the love around to the different teams.

Here's the rundown in alphabetical order:

Chris Ash, Wisconsin, defensive coordinator/secondary: All the attention on the offense's turbulent season took the spotlight away from the good things happening on the defensive side. Wisconsin finished in the top 25 nationally in total defense, scoring defense, rushing defense and pass efficiency defense. The Badgers held nine opponents to 21 points or fewer and gave an inconsistent offense chances to win every time out. Ash will be missed as he joins ex-Wisconsin coach Bret Bielema at Arkansas.

Tim Beck, Nebraska, offensive coordinator/quarterbacks: The second-year play caller oversaw the Big Ten's top offense, which averaged 462.2 yards per game (24th nationally) and 35.1 points per game (28th nationally). Junior quarterback Taylor Martinez made significant strides under Beck's watch, and Nebraska survived the loss of star running back Rex Burkhead for most of the season thanks to contributions from Ameer Abdullah and others.

Tracy Claeys, Minnesota, defensive coordinator: An improved defense sparked Minnesota to a 4-0 start and eventually to bowl eligibility for the first time since the 2009 season. The Gophers pass rush showed life for the first time in years as senior end D.L. Wilhite and others put pressure on opposing quarterbacks. Minnesota was especially good against the pass, ranking 11th nationally and 20th in pass defense efficiency. Although the offense remains a work in progress, Minnesota should be pleased with the direction on defense under Claeys.

Adam Cushing, Northwestern, offensive line: Cushing's recruiting ability always has stood out, but his coaching skills had been questioned as Northwestern struggled to convert promising line prospects into powerful blockers. The Wildcats went from a finesse offense to a power offense this season, blasting off of the line to the tune of 230.9 rush yards per game. Red zone offense went from a weakness to a strength as Northwestern tied for 17th nationally. Cushing's line paved the way for star running back Venric Mark.

Rich Fisher, Nebraska, wide receivers: Nebraska isn't known for its wide receiver play, but things are changing under Fisher's watch. Led by standout sophomore Kenny Bell, the Huskers' top three receivers combined for 1,657 yards and 11 touchdowns on 115 receptions. Just as important, the receiving corps helped Nebraska's bread-and-butter run game with effective blocking throughout the season. Fisher's hiring after the 2010 season raised some eyebrows, as he had taken a break from college coaching, returned to the high school ranks and also served as a golf instructor in Massachusetts. But he definitely looks like a great addition to Bo Pelini's staff.

Patrick Higgins, Purdue, wide receivers: Higgins played a significant role in Purdue's late-season surge, as he took over the offensive play-calling duties after coordinator Gary Nord suffered a severe back injury. Purdue won its final three games with Higgins and head coach Danny Hope handling the play calls. Higgins also did a nice job with Purdue's wide receiving corps, despite the fluctuating quarterback situation. Three veteran Boilers receivers eclipsed 40 catches and 300 receiving yards, and redshirt freshman Dolapo Macarthy showed promise.

Seth Littrell, Indiana, offensive coordinator/tight ends/fullbacks: Head coach Kevin Wilson brought in Littrell to boost Indiana's passing attack, and Littrell delivered despite losing starting quarterback Tre Roberson in Week 2. Indiana went from 80th nationally in pass offense to 19th, leading the Big Ten with 311.2 yards per game. With help from assistant offensive coordinator/quarterbacks coach Kevin Johns, Littrell managed the quarterback situation pretty well as both Cameron Coffman and Nate Sudfeld had success. Littrell will go largely unnoticed because of Indiana's low profile and 4-8 record, but he was one of the Big Ten's best coaching additions for 2012.

Curt Mallory, Michigan, secondary: Michigan's defensive line dominates the spotlight because that's where coordinator Greg Mattison and head coach Brady Hoke put their primary focus, but Mallory has done a really nice job with a secondary that struggled mightily under the previous regime. Despite losing promising cornerback Blake Countess to a torn ACL in the season opener, Michigan still finished second nationally (behind Nebraska) in pass defense (155.2 ypg allowed). Safety Jordan Kovacs has blossomed under Mallory's watch, and while the depth in the secondary isn't where it will be eventually, Mallory has managed things well.

Bart Miller, Wisconsin, offensive line: Miller began the season as a graduate assistant and moved into one of the team's top assistant roles in Week 3 after the surprising dismissal of veteran line coach Mike Markuson. Although Wisconsin's line didn't have its typical dominant performances every time out, Miller fostered obvious improvement and cohesion during the course of the season. The finished product showed up in the Big Ten championship game against Nebraska, as Wisconsin bullied the Huskers to the tune of 70 points, 539 rushing yards and eight rushing touchdowns.

Reese Morgan, Iowa, defensive line: Iowa didn't have much to cheer about in 2012, and some of the staff changes Kirk Ferentz made led to some growing pains. Morgan faced a significant challenge in moving from offensive line to defensive line, which returned only a handful of players who had logged field time in 2011. Given the youth and inexperience along the Hawkeyes' defensive front, Morgan did a nice job in Year 1. Joe Gaglione had a nice senior season (9 tackles for loss, 5 sacks, 2 forced fumbles) and young players like Louis Trinca-Pasat showed promise. The line held its own in the first half of the season before struggling late.

Pat Narduzzi, Michigan State, defensive coordinator: Many of these assistants took questionable units and improved them. Narduzzi led an elite defense that entered the season with high expectations and met them. Make no mistake: Michigan State's defense is the only reason the team found itself in every game this season. The Spartans had a few standouts, namely linebacker Max Bullough, but their overall team defense and stinginess stood out. Narduzzi is one of the nation's premier coordinators and should land a head-coaching job in the near future.

John Strollo, Penn State, tight ends: Although O'Brien's offense is a tight end's dream, Strollo did a terrific job of developing young and unproven players this season. Redshirt freshman Kyle Carter emerged into one of the Nittany Lions' top passing threats, and junior Matt Lehman and true freshman Jesse James also stepped up at times. Of Penn State's top five receiving-yards leaders this season, three players are tight ends (Carter, Lehman and James).

Ed Warinner, Ohio State, offensive line/co-offensive coordinator: Warinner took an underachieving Buckeyes offensive line with serious depth questions and turned it into quite possibly the best line in the league. The Buckeyes' front five turned a corner in Big Ten play and created lanes for Braxton Miller, Carlos Hyde and the Big Ten's top scoring offense. Warinner was the Big Ten's best assistant hire of the last offseason and earns our vote as the league's top assistant in 2012.