Steve Belichick, a college football coach and celebrated scout for 43 years and the father of New England Patriots Coach Bill Belichick, died of heart failure Saturday night at his home in Annapolis, Md. He was 86.

''I found out about it the middle of last night,'' Bill Belichick told The Associated Press yesterday after the Patriots defeated New Orleans, 24-17, in Foxborough, Mass. ''I coached this game with a heavy heart.''

Bill Belichick said his father watched Navy's 38-17 victory over Temple in Annapolis on Saturday, then watched more college football on television. ''He went peacefully,'' he told The A.P.

Belichick and his father stood together on the sideline last February in Jacksonville, Fla., where the Patriots won their third Super Bowl in four years.

The elder Belichick was an assistant coach for 10 years at Vanderbilt and North Carolina, then for 33 years at Navy. He seldom saw Navy play because he spent most football Saturdays scouting Navy's next opponent. ''He was a genius,'' Joe Bellino, Navy's Heisman Trophy winner in 1960, told The New York Times in August 2004. ''On Monday nights, he would give us his scouting reports, and even though we were playing powerhouses, I always felt we were prepared because he found a way for us to win.''

Wayne Hardin, one of seven head coaches during Belichick's tenure at Navy, recalled a game against Michigan.

''They had an all-American back who played offense and defense,'' Hardin said. ''Steve said, 'When he's on defense and you run an off-tackle play, that guy will get right up in the hole, so you can throw behind him.' Late in the game, we faked a run off tackle, he comes running up and we throw over him for a touchdown and win the game.''

Hardin said Belichick would have been too nervous to watch Navy games. ''He could watch the Army-Navy game,'' Hardin said, ''because it was the last one of the season, but he wouldn't go. Finally, we got him there because we had an end-zone box with no other people, so he could be by himself. There was also a phone there, and we said if you see anything we should know, you can call us. He called.''

In 1963, Belichick wrote a book, ''Football Scouting Methods,'' which Houston Texans General Manager Charley Casserly called the best book on scouting he had ever read.

Stephen Nickolas Belichick was born in 1919 in Monessen, Pa., and he grew up in Struthers, Ohio. After graduating from Case Western Reserve University in Cleveland in 1941, he wanted to become a high school coach, but he faced the prospect of military service.

He got a job as an equipment man for the Detroit Lions of the National Football League. There was no salary, but each player put a dollar a week into a pool to pay him.

The Lions had the same single-wing, fullback-oriented offense used by Case Western Reserve, and Belichick helped coach the Lions' fullbacks and started running the plays. When the team started 1-2-1, he was activated as a player and was paid $115 a game. He was the blocking back for Byron White, who would become an associate justice of the United States Supreme Court. Belichick had no complaints about his job.

''You could buy a new Ford back then for $600,'' he said. ''Things were cheap. I was paying $1 a day to stay at the Hotel Saverine in downtown Detroit.''

At just under 5 feet 11 inches and 193 pounds, he was not big, and in those pre-facemask days, his face was beaten up. After his first season, he joined the Navy and served as an officer in Normandy and Okinawa.

He was married in 1951 and lived in Annapolis, Md., starting in 1956. Besides Bill, he is survived by his wife, Jeannette, and three grandchildren.

His son quickly became obsessed with football. At 5, Bill Belichick sat on the family porch and listened to Navy assistant coaches talking football. At 6, he memorized Navy's plays. At 9, he went to the weekly meetings, where his father gave scouting reports to the players. At 10, instead of doing homework, he analyzed film and diagrammed plays. At 12, he and his father drew up offensive plays, then created defenses to stop them. The father once said of his son:

''He's intelligent. He inherited his mother's brains. My friends were his friends, and most of my friends were coaches. If I were a doctor, I'm sure he wouldn't be in football.''

Stephen Belichick (1919)