Several new assistant coaches in 2013 made major impacts on established coaching staffs in the Big 12 during their first seasons on campus. Oklahoma State had two new coordinators making an impression; a pair of Oklahoma assistants revamped its line play; and a Kansas State alumnus helped a current Wildcat become a multipurpose star.

Here are the top 10 coaching hires of 2013 in the conference (Note: Since Texas Tech's entire staff was in its first season, the Red Raiders were excluded):

1. Glenn Spencer, Oklahoma State defensive coordinator: The OSU defense rose to another level during Spencer’s first season as defensive coordinator. The veteran coach, who had spent time as a defensive line coach and linebackers coach during his six seasons at OSU, took over the defense in 2013 and made it more aggressive and productive. OSU finished among the top 3 in the Big 12 in points allowed per game (21.6 points, 1^st), yards per play (4.77, 2^nd) , yards per rush (3.64, 3^rd), third down conversion rate (31.4 percent, 1^st) and yards per pass attempt (5.8, 1^st). The Cowboys also forced a Big 12-best 33 turnovers, 11 more than they did in 2012.

2. Jerry Montgomery, Oklahoma defensive line coach: The Sooners' defensive line improved tremendously during Montgomery’s first season. OU saw its tackles for loss jump from 53 in 2012 to 73 in 2013, and sophomore defensive end Charles Tapper went from raw talent with terrific upside to an All-Big 12 performer. In addition, Montgomery’s defensive line was able to handle the mid-season loss of defensive tackle Jordan Phillips as redshirt freshman Jordan Wade stepped into Phillips' spot without a major drop off in production.

3. Greg Robinson, Texas defensive coordinator: Robinson stepped in, replacing Manny Diaz, after the Longhorns' defense was embarrassed during the first two games of the 2013 season. The Longhorns defense didn’t transform into a dominant unit but Robinson stopped the bleeding after UT allowed 1,025 yards in its first two games. BYU and New Mexico State combined to averaged 2.48 points per drive. In UT’s final 11 games, opponents averaged 1.68 points per drive.

4. Bill Bedenbaugh, Oklahoma offensive line coach: The Sooners' first-year offensive line coach did a terrific job with a unit that was forced to shuffle around at various times this season. OU’s Sugar Bowl win was a great example of his impact as three of the five offensive linemen who started the game were making their first start in their career or first start at a new position. Guard Dionte Savage made his lone start of the season, right tackle Daryl Williams moved to left tackle and guard Bronson Irwin shifted to right tackle and held their own as the Sooners knocked off Alabama.

5. Larry Porter, Texas running backs coach: Porter did a good job with UT’s running backs during his lone season as the running backs coach. Malcolm Brown and Johnathan Gray combined for 373 carries, 1,684 rushing yards and 13 touchdowns. Just as important, the duo lost zero fumbles despite carrying the rushing load. Porter helped a talented group of running backs to be productive and protect the ball during his short stint at UT.

6. Andre Coleman, Kansas State receivers coach: As Tyler Lockett made catch after catch while overwhelming Big 12 secondaries, Coleman’s spot on this list became more and more secure. Lockett was a terrific playmaker and returner during his first two seasons in Manhattan, Kan. But in 2013 he became a terrific receiver as well. His route running and ability to consistently get open was a sign of the improvement he made under Coleman’s tutelage. Lockett had 81 receptions for 1,262 yards and 11 touchdowns as a junior. In 2012, he finished with 44 receptions for 687 yards and four scores, although to be fair, the Wildcats threw the ball less during his sophomore season.

7. Mike Yurcich, Oklahoma State offensive coordinator: Oklahoma State’s offense was still among the Big 12’s best under Yurcich, finishing among the top three in the conference in points scored (39.1 points, 2^nd), yards (448.8, 3^rd), yards per play (5.91, 3^rd) and passing yards (278.85, 3^rd). Yet the Cowboys took a clear step backward in a few categories. OSU dropped from third nationally (7.01) to No. 45 in yards per play (5.91) and dropped from tied for 24^th nationally (46.2 percent) to No. 80 in third down conversion rate (38.8 percent). Yurcich’s first season as a Division I coordinator wasn’t bad by any stretch, but it was far from perfect.

8. Tony Gibson, WVU safeties: Gibson left Arizona to join the Mountaineers’ staff as the safeties coach before the 2013 season. Darwin Cook continued to be one of the most productive defensive backs in the Big 12 under Gibson, earning All-Big 12 honors with 74 tackles and four interceptions as a senior. With WVU's defensive coordinator position open, Gibson could be a good fit to take over that side of the football.

9. DeMontie Cross, TCU linebackers: The veteran coach with NFL experience helped the Horned Frogs' linebackers rank among the team's top tacklers. Junior Paul Dawson went from 14 tackles as a sophomore to a team-high 91 tackles in 2013. Marcus Mallet (70) and Jonathan Anderson (66) joined Dawson among the top four tacklers on the Horned Frogs defense during Cross' first season.

10. Lonnie Galloway, WVU receivers: The Mountaineers' quarterbacks had a rough year yet the receivers as a whole were fairly productive, with WVU finishing fourth in the Big 12 in receiving yards from its receivers (2,604). Five different Mountaineers receivers caught at least 20 passes, including Ronald Carswell and Mario Alford, who each averaged at least 20 yards per reception.