Bob Horner is the National League rookie of the year, the first since Willie McCovey of San Francisco in 1959 to win the honor after joining his team in mid-season and the first No. 1 selection in the draft of graduating high school and college players to move immediately into the majors and win the prize.

The Atlanta Braves' third baseman drew 12 1/2 votes from a 24-member committee of the Baseball Writers Association of America. Ozzie Smith, San Diego's great-fielding, .258-hitting, 40-base-stealing shortstop, attracted 8 1/2 nods and Don Robinson, the 14-6 Pittsburgh pitcher, the other three votes.

Horner was in the Atlanta starting lineup a week after making the last out for Arizona State in its loss to Southern Cal in the College World Series final. A record-breaking home run hitter at ASU, he stepped right up and belted one off the Pirates' Bert Blyleven in his first game and went on to total 23 homers, 17 doubles and a triple among 86 hits, good for 63 RBI and 50 runs scored on a .266 batting average in 89 games.

Says Brave Manager Bobby Cox: "This kid is going to make it big. His biggest problem is a tendency to put on weight. He'll have to watch that . . . "