Columbia, Mo. ? When Kansas University’s undefeated basketball team tipped it off Saturday night against rival Missouri, four top-15 teams had been knocked off earlier in the day by unranked opponents.

Maryland stunned North Carolina. USC’s freshman-dominated team traveled across town and gave UCLA its second loss. Kansas State, another freshman-heavy roster, jazzed its fans with a blowout victory against Texas A&M. Cincinnati reached .500 by upsetting No. 15 Pittsburgh.

What does it all mean? It means the term “Final Four lock” just doesn’t apply to college basketball. Not this year. Not many years.

Too much talent dots rosters across the country, and too much emotion enters the equation with college athletes.

Blessed with such a versatile, deep, experienced roster of well drilled, unselfish athletes, Kansas is about as upset-proof as any team. The Jayhawks will be ranked either first or second in the nation, alongside Memphis, when the polls are released Monday.

Yet, even KU coach Bill Self called his team “a little lucky” Saturday night because some Missouri players didn’t hit shots they usually hit during KU’s 76-70 victory. Many Kansas opponents finish games feeling that way, which means part of it has to do with the defense the Jayhawks consistently play. Yet, defense didn’t have anything to do with the Tigers missing half of their 22 free throws on a night Kansas shot 45 of them and made just 28 for an accuracy rate of .622.

Upsets happen in college basketball. If they didn’t, it would be too boring to bother following. If Kansas wants to take a positive out of this one, it’s that an upset didn’t happen in a hostile environment and on the same Mizzou Arena floor where Texas recently suffered a 13-point loss.

A perfect record doesn’t mean a perfect team, as Kansas showed in failing to make the most of so many opportunities to bury Mizzou.

Bad free-throw shooting kept that from happening.

In the case of Brandon Rush, bad shooting, period, kept the margin close throughout. Sometimes bad shooting nights can be blamed on ridiculous shot selection. Not this time. So many of Rush’s shots looked so true, then bounced softly off one side of the rim onto another side, then slowly trickled off. Exhibiting the type of aggressiveness needed of him, Rush misfired on 12 of 14 field-goal attempts and all four three-point tries. He did make nine of 14 free throws, getting to the line far more often than usual because he took it to Mizzou.

If the same Matt Lawrence who shot so well against Kansas in Allen Fieldhouse last season hadn’t experienced shooting woes similar to Rush’s, Memphis could be standing alone among Division I schools with an undefeated record.

But Lawrence didn’t have it, and Kansas (18-0, 3-0) didn’t lose.

Asked by a Missouri beat writer who understands college athletics quite well whether he was surprised by the narrow margin of victory, KU coach Bill Self said, “Anybody who thought we were going to win this game big probably doesn’t really understand college athletics.”

This much is easy to understand about college basketball: Too many variables and too much parity makes it absurd for any one school to be considered a Final Four lock. Not even Kansas.