[2][3] He was highly successful at school level, winning four straight titles in the 440-yard dash/400-meter dash from 1978 to 1981 at the UIL Texas State Track and Field Championships (the second man to do so after Kenneth Thomas of Wortham).

At the 1981 IAAF World Cup, his performance in the 4×100-meter relay alongside Mel Lattany, Stanley Floyd and Steve Williams brought the United States team the bronze medal.

[10] A gold medal in that event also came at that year's Universiade, as the American team of Lattany, Ketchum, Jason Grimes and Calvin Smith topped the podium.

[13] Outdoors, he helped the team's 4 × 100 m relay quartet (including Carlton Young, Mark McNeil, and Stanley Floyd) to a world under-23 best time for the event in 38.53 seconds.

[14] Ketchum claimed the relay title with the Cougars at the 1982 NCAA Men's Outdoor Track and Field Championships in an American collegiate record of 39:12 seconds.