The Maryland Racing Board's decision to rescind the rule allowing a trainer to run horses as separate betting units came as little surprise to racing fans at Pimlico.

What was surprising was the Board's refusal to permit fewer horses than the present eight to compete in a triple race. In the past, representatives of the tracks have prevailed almost every time when the track's interests conflicted with those of the racing fans.

But in Thursday's meeting of the racing board here, Commissioner Frank Cucchia said, "The fan has little shot now with 25 percent being taken out in the triples. He deserves to have more than three, four, five or six horses to bet on. Between the takeout and the fewer horses running in the triple the fans would be left with peanuts."

In other racing board business, an eloquent plea for the reinstatement of banned jockey Jesse Davidson by agent Peggy McCarron was taken under advisement. McCarron asked the board to consider licensing Davidson as an exercise boy. The board turned down a similar plea last year.

The exploits of the crack 3-year-old Dave's Friend, is a subject of much discussion since his sparkling race and appended workout Tuesday. Dave's Friend is expected to hook up with the rugged Star De Naskra and the once-brilliant Sensitive Prince in Pimlico's closing-day feature, The Marylander, at 1 1/8 miles.