The Maryland thoroughbred racing scene will move to Pimlico in Baltimore Saturday.

The opening card features 14 3-year-old fillies going six furlongs in the $30,000-added Politely Stakes. The probable favorite is Swift Attraction, winner of her only two starts. The bay will be ridden by Jorge Tejeira in her first added-money event.

Chief contention is expected to come from Gosh All Hemlock, Inclavatating and Jove's Lady.

The 107th Preakness Stakes will be run May 15 and the meeting closes the following Saturday, May 22. With about 1,000 horses stabled at the track and as many at neighboring tracks, Racing Secretary Lawrence Abbundi should have enough racers from which to draw.

Nominations for this year's Preakness have reached 324, the second year in succession there have been more than 300.

Pimlico has installed 15 new television monitors and will have its own closed-circuit television station, WBET.

The appointment of a racing commissioner by Gov. Harry Hughes to the job vacated by Porter Hopkins is expected shortly. Hopkins, a Republican, resigned from the commission to run for the U.S. Congress from the Eastern Shore. Leading candidates for the post are Jervis Finney, former state senator and federal prosecutor, and Dr. Alex Mallis of Baltimore County. Mallis races horses under the stable name of The Little Luck Farm.

Laurel Race Course again will change its racing surface, adding more loam to its sandy strip. The Anne Arundel County track has been plagued in recent seasons by washouts and a lack of uniformity of its racing surface.

Laurel will charge $3 general admission for all parts of its racing plant, including grandstand and clubhouse, when it opens for its summer meeting May 24; for those who wish to watch the races from the turf club, the price will be $6.

The Laurel meeting will last 48 days, through July 19.