The Big 12 schedule arrives at its midseason point over the next three days with the top and the bottom of the standings occupied by the teams as projected in the preseason. Kansas got all of the coaches first-place votes, TCU was named 10th in all of the ballots. Through the seasons first five weeks neither gave much indication of landing elsewhere.But perceptions changed Saturday at the top.The Jayhawks home loss to Oklahoma State doesnt alter their role as favorite but the idea of lapping the field is shelved after the Cowboys exposed flaws in a hard-fought triumph.Had Kansas won and remained unbeaten in league play, the closest challenger, Kansas State, essentially would have reached the turn three games behind two in the loss column and already with a home loss to the Jayhawks on the ledger.Now, K-State, at 6-2 after Saturdays gut-check triumph at Oklahoma, controls its future. Stay one game behind the Jayhawks, 7-1, and find a way to win in Lawrence next Monday night and the Wildcats will be tied for first heading into a final month dogfight.Four others with three league losses have to feel a more energized for a second-half challenge, thanks to Oklahoma State and the terrific play of Marcus Smart and Markel Brown, who combined for 53 points in the 85-80 victory.Dropping league games was likely at some point for these Jayhawks, who had escaped plenty of danger lately. But losing at home, which had happened only once in six years, to a team that hadnt won on the road this season?All we did was invite everybody right back into it, Kansas coach Bill Self said.The Big 12 has separated into a top six and bottom four, and it serves as something of a microcosm for the all of college hoops. This season is without a dominant power, and when the Associated Press poll is announced on Monday, a new No. 1 team will emerge for the fourth straight week. It would have been KU had it won on Saturday.In the nation and the Big 12, there are plenty of good teams. Great ones? Not this year. Its as if college basketball is loaded with sixth through 10th seeds.The Big 12s upper echelon Kansas, K-State, Baylor, Oklahoma State, Oklahoma and Iowa State would be in the NCAA Tournament if the season ended today, most as sixth through 10th seeds.Kansas, like other Big 12 contenders, plays those bracketology guessing games, especially in the second half of the conference season because the championship race is typically not a question for many. Last year, Kansas and Missouri took the race deep into February until the Jayhawks won by two games. In 2010, Kansas fronted the league by four.And a strong finishing kick may happen again. Kansas typically reacts well to disappointment. Last year, the December loss to Davidson at Sprint Center changed the Jayhawks resolve and they roared to their eighth straight Big 12 championship and to the national-title game.The conference championship streak carries deep meaning for the program, and this is a senior-dominated team. If only for those intangibles, the Jayhawks remain the Big 12 favorite. Theyve been there, done that, and know what it takes to win.But the big advantage Kansas seemed to have throughout the non-conference portion of the schedule and the first half of the league race shrunk on one afternoon at Allen Fieldhouse. Oklahoma State revealed a vulnerability in the Jayhawks, and in the process may have created conference drama for the top spot.