Go Go Roger and On The Sly are top-weighted in their respective divisions for Saturday's split Riggs Handicap at Pimlico.

On The Sly is tabbed at 120 pounds in the first division of the 1 1/16-mile turf event, which drew nine entrants.The 4-year-old son of French turf champion Roi Dagobert will agin be ridden by Gregg McCarron. He will be conceding truf-racing experience to most of his adversaries, having lost his only start on the grass last May at Garden State.

Chief challenge to On the Sly is expected to come from Ogden Phipps' Landscaper and Rlpon. The former is held at 117 pounds and has added money wins on the turf. Ripon has chased On The Sly on the dirt this year but shows stronf turf form and could threaten with the light impost of 112. Lanscaper will be ridden by Leroy Moyers while Ripon has Kelly Castaneda.

In the second division, Go Go Roger has a difficult assignment, facing some of the more capable turf performers in the area. His chief opposition is expected to be Chatt, winner of three races on the Grass, two of them in added-money events.

Chati totes the second highweight of 118 and will be ridden by the skillful Donald Brumfield. Go Go Roger has Vincent Bracciale, the meeting's leading jockey, scheduled to ride.