It is hard to take a firm stand on any of the seven horses running in the $50,000 Three and Four Year Old Sales Stakes at Northlands Park on Saturday, so it might be worth following the bouncing Walcott. That would be Rico Walcott, who is dominating the jockey standings at Northlands and rode four of the horses entered to wins in their last start.Walcott bailed on all four, however, and will be aboard Northern Yankee in the 6 1/2-furlong feature, which headlines a strong 10-race card.Trained by Craig Smith, Northern Yankee came off a long layoff when he finished fourth in a second-level allowance race June 21, and he could take a big step forward with a race behind him. It was his first start since he finished second in an unrestricted allowance race on turf at Tampa Bay Downs in March 2012. In his previous start, he rallied to win a $75,000 optional claimer going five furlongs in his first try on turf.Northern Yankee forced a fast pace before tiring late with apprentice Amie Pooli aboard in his comeback race, and the lightly raced 4-year-old appears to be primed for a big effort, with bullets fired in back-to-back works July 5 and July 13.There is plenty of speed in the field, including Kingoftherockies, whom Walcott rode to four straight wins for trainer Robert MacDonald at this meet. All four races were contested over six furlongs, and each time, Kingoftherockies broke on top and never looked back. He is coming off a smart win over Points Alert in a $17,500 claimer for 3-year-olds and up June 29. He drew the rail, where Ismael Mosqueira will be asking him to use his substantial speed while leaving the starting gate.Pooli will pick up the mount from Walcott on Gilded Eagle, who is coming off a win in a $15,000 claiming race for nonwinners of two.Walcott was aboard for Clever Speed’s front-running win in a 6 1/2-furlong maiden special weight race June 26. Fernando Perez will be aboard the 3-year-old son of Lost Canyon on Saturday.Arctic Ceal won his last two starts in conditional-claiming races with the leading rider aboard and figures to have a hard time keeping up with the other speed with Nate Smith taking over.Silent Sam rallied to win a $25,000 optional claimer in his only start this year, and Saturday’s race could set up well for him.Hollywood Drama won three stakes as a 2-year-old last year but wasn’t much of a factor when he ran against a tough field in a $35,000 optional claimer for 3-year-olds and up in his 2013 debut July 6.