Bob Blackman, an innovative football coach at Dartmouth, Illinois and Cornell in a career that spanned 34 seasons, died Friday at a hospital in Burlingame, Calif. Blackman, who lived in Hilton Head, S.C., was 81.

Blackman's wife, Katharine, said he was hospitalized while they were on vacation in Singapore and was found to have a bacterial infection and anemia. While they were flying home last Thursday, his condition worsened and he was taken to a hospital after their flight landed in San Francisco.

Coaching 16 seasons at Dartmouth, Blackman led his teams to seven of the first 15 championships in formal Ivy League play, and his squads were undefeated and untied in 1962, 1965 and 1970.

It was his recruiting zeal that caught the attention of the eight-team Ivy League. ''Bob taught the Ivies how to recruit nationally when there were no numbers limitations,'' Seaver Peters, a former Dartmouth athletic director, once said. ''He had a national network.''

Blackman's 1970 Dartmouth team, which held six of its nine opponents scoreless, concluded with a rare-for-the-Ivies top-20 ranking (14th) in the two national polls and won the Lambert Trophy as the best team in the East.

Penn State Coach Joe Paterno, partly in jest, challenged this award and suggested a postseason game between his team -- a perennial national power -- and Dartmouth. ''If we were allowed to play a postseason game, I'd prefer to play a team with a better record,'' Blackman replied. Penn State's was 7-3.

After that season, it was on to Illinois for Blackman, whose goal was to build championship teams to represent the Big Ten in the Rose Bowl game, which was a shrine of sorts for Blackman.

He was an alumnus of the University of Southern California, a native of Long Beach and he had played in the Rose Bowl in a high school championship game.

As an 18-year-old U.S.C. freshman football player, Blackman was stricken with polio on his right side and given little chance to walk again. But a year later he was playing football again, limping through the drills. The head coach, Howard Jones, kindly made him an assistant freshman coach -- and the vocational die was cast.

Blackman, who was left with mild polio limitations, disliked any handicap classification. He made a point of showing up -- with skis -- at the Dartmouth ski area during Winter Carnival weekends.

He served in the Navy during World War II and began college coaching at Pasadena City College in 1949, taking his teams to national junior college championships in 1951 and 1952. They played home games at the Rose Bowl.

Next he went to Denver University for two seasons, taking the Pioneers to their first Skyline Conference title in 34 years. Along the way he was tinkering with something he called the V-formation, a forerunner of the wishbone offense, and with original, intricate defenses.

Dartmouth sought a new coach and persuaded Paul Brown, coach and founder of the Cleveland Browns of the National Football League, to review candidates. Brown's son, Mike, was the Dartmouth varsity quarterback.

''Red Rolfe, the former New York Yankees' third baseman and a Dartmouth alumnus, was the athletic director,'' Mike Brown recalled. ''He sent game films of the three leading candidates, and my father and his staff recommended Bob Blackman.''

Blackman's record at Dartmouth was 104 victories, 37 defeats and 3 ties.

As Blackman's first Dartmouth quarterback, in 1955, Mike Brown scored 10 touchdowns. ''All of them were scored on quarterback sneaks,'' Brown remembered. ''Bob made sure my accomplishment was a big part of that year's highlight film. The film was shown at a Dartmouth alumni gathering in my hometown, Cleveland, and by the time the last quarterback sneak came up, the audience was giggling. I was embarrassed.''

Attention to the smallest details, quarterback sneaks or whatever, was a part of Blackman's preparation, which included use of early computers in accounting for opponents' offensive tendencies.

''He knew exactly what he wanted each player to do on every play,'' Brown said. ''And he could coach every position.''

One of Blackman's most memorable players was Jake Crouthamel, a running back from 1957 to 1959 who succeeded him as head coach in 1971 and is currently director of athletics at Syracuse University.

At Illinois, there were no invitations to the Rose Bowl and disillusionment set in. His teams' results over six seasons were modest -- 29 victories, 36 losses, 1 tie. So Blackman returned to the Ivies, going to Cornell, coaching his teams there to 23 victories, 37 defeats and a tie, with his best finish second place in 1980.

Despite the less-than-overwhelming success his second time around in the Ivies, Blackman once remarked: ''I like the Ivy League -- the only conference where the coaches are paid more than the players.''

In addition to his wife, Blackman is survived by a daughter, Julie, of Hilton Head, and two granddaughters.

Robert L Blackman