Undated (AP) _ For a guy who never ducked a fight or gave up anything without one, Bill McCartney seemed remarkably resigned to giving up coaching.

During 13 seasons at Colorado, McCartney's uncompromising personality and his insistence on wearing his religion on his sleeve rubbed more than a few people the wrong way.

Those convictions led to skirmishes with the university administration, some players and their parents, and sometimes in court, on matters ranging from team prayers and drug testing, which he favored, to homosexuality and abortion, which he was against.

More than anyone else in college football, McCartney was the guy you figured would go out on his shield. So what made the timing of Saturday's announcement so unusual was how far into the background all those controversies had receded, how little fighting there was left to do by the time he actually walked away.

When the day dawned, the 54-year-old McCartney had never seemed more secure. He was only three seasons removed from a national championship, he had stabilized his coaching staff, reduced his own responsibilities and was looking more and more like a man who might go on coaching forever.

One moment he was tethered to the university by a ''lifetime'' contract. And in the next, without so much as a word of warning to almost anyone who knew him, McCartney was invoking an option that allowed him to dissolve the bond after five years.

''You heard the whole story - there is nothing hidden,'' he said at a Saturday news conference just moments after Colorado's regular-season ending win over Iowa State. ''There are no negatives here; there are no complaints. It's strictly a very positive thing, and that's the truth.''

During a Sunday night appearance on his weekly television show, McCartney sounded most of the same notes he had a day earlier. He was not departing for health reasons, or because there were problems at the school, or with the NCAA, or an impending scandal. Basically, he reiterated, he was leaving to spend more time with his family.

That is scheduled to begin as soon as the Buffaloes finish the season with a Jan. 2 appearance in the Fiesta Bowl. McCartney said though he has no plans to return to the profession, he couldn't rule out a return some day.

''I know people are asking the question, 'What's behind this?''' he said Sunday night. ''All that's behind this is that it's time.''

Maybe so. But considering the way McCartney's career has gone, something tells us this won't be the last time we hear from him.

Like the steady stream of running backs he recruited out of California and plugged into the option attack, he was tough to get a handle on. Every time you thought you had him, McCartney left you grasping air.

Even the man who first spotted those grand ambitions and gave McCartney his start in college football was only slightly less stunned than the rest of us by the decision.

Some 20 years ago, Bo Schembechler was the coach at Michigan and already something of an institution around the state. He remembers McCartney working as football and basketball coach at Divine Child High School, driving over from nearby Dearborn in his spare time to attend clinics in Ann Arbor, an eager kid destined to make it in the big time.

The intervening years proved Schembechler's hunch right. After eight years as an assistant in Ann Arbor, McCartney moved on to Boulder to become head coach. He revived the moribund program he inherited from Chuck Fairbanks, won the one national championship and nearly another, and became something of an institution in his own right.

Now, McCartney is about to become a legend in retirement. The fact they are finally equals doesn't surprise Schembechler, although Bo couldn't know it would happen this soon.

Even so, like the rest of us, he is prepared to take his former pupil at his word.

''There's no such thing as an ideal time to get out of the business, so I'm not going to read anything more into it,'' Schembechler said, ''unless I hear it from him.''