Posted by ESPN.com's Tim Griffin
St. Patrick's Day is a time to celebrate all things green, including the best of college football rivalries.
It's understandable that many Big 12 teams have developed fierce enmity for their conference rivals over the years -- and even more for some than others.
Here's a look at what makes the supporters of each school green with envy all days, but especially on St. Patrick's Day.
Baylor: There have been no bowl trips for the Bears since 1994 -- the longest streak in the Big 12 and one of the longest of any school in a BCS conference. Even though they made the cut into the Big 12, it peeves Baylor fans of TCU's success in recent years. The Horned Frogs have developed into a top-10 program with 10 bowl appearances, four straight bowl victories and two straight victories over Baylor since the Big 12 was formed.
Colorado: The Buffaloes haven't been a factor in the Big 12 North since Gary Barnett was fired after the 2005 championship game loss to Texas. And it has to gall their most ardent supporters even more that Nebraska appears to have turned the corner as the North Division's likely favorite with a strong coach like Bo Pelini in place for the future.
Iowa State: The Cyclones have to look outside the conference because they have been the whipping boys for the rest of the Big 12 since Dan McCarney left. Cyclone fans can't be happy that Iowa coach Kirk Ferentz appears to have weathered a recent downturn and has the Hawkeyes pointed back in the right direction.
Kansas: It can't make Jayhawk fans happy that the first time the Jayhawks have made back-to-back bowl trips in school history, arch-rival Missouri won the Big 12 North championship in both of those seasons. Even a victory over the Tigers in the muck at Arrowhead Stadium last season didn't help take the sting for Jayhawks of seeing the Tigers again play for the conference championship.
Kansas State: The Wildcats have struggled through their worst stretch since before Bill Snyder arrived for the first time in 1989. It hasn't helped that their arch-rivals across the state at Kansas has made back-to-back bowl trips and won both bowl games in the past two seasons. It's even more irksome that former Kansas State assistant coach Mark Mangino has been directing the Jayhawks' recent success.
Missouri: The Tigers have claimed back-to-back division championships, but old Big Eight rival Oklahoma has been waiting each season to deny them a chance at the Big 12 title. Even worse, the Sooners have won those games by a combined margin of 100-38. And that's 19 victories for the Sooners in the last 20 games against Missouri.
Nebraska: The old proud Big Eight power hasn't been able to duplicate that success on a continual basis in the Big 12. It seems that schools like Texas and Oklahoma have always been standing in their way. The Cornhuskers seemed to lose a little mystique in the first Big 12 championship game when Texas upset them. And they never seemed to have recovered - particularly in recent years when football championships have been rarely savored by Cornhusker fans.
Oklahoma: The recent losing streak in BCS games has taken some of the national appreciation away from the Sooners' recent unprecedented string of three straight Big 12 titles. But Boise State, West Virginia and Florida have kept the Sooners from duplicating their success on a national level. It's made those titles pyrrhic victories for Bob Stoops.
Oklahoma State: The Cowboys have never made a BCS bowl game or Big 12 championship during the conference's brief history. But Oklahoma has infuriated Cowboy fans by claiming six titles during the conference's 13-season history. It doesn't make for much fun in bragging rights for Bedlam when the Sooners have dominated the conference so significantly during that time.
Texas: Mack Brown has taken the Longhorns back into contention in the Big 12 title race after inheriting a program that was in shambles. But even with the top run in program history since the days of Darrell Royal, the Longhorns still have recorded only one Big 12 championship during his coaching span. Even worse, the Sooners have scoreboard, 6-1, in Big 12 football championships during the time that Brown and Bob Stoops have coached their programs.
Texas A&M: But it could be worse. The Aggies have been rendered a non-entity in recent seasons in the Big 12. And it's even more galling that arch-rival Texas has finished ahead of A&M each of the past 10 seasons.
Texas Tech: It didn't make Texas Tech fans very happy when they were left out of much of the discussion for the championship despite forging a three-way tie with Texas and Oklahoma for the South Division crown last season. It's made the rivalry with those two South rivals even more keen than before -- if that could be possible.