With a good start, J Best Boogie is an outstanding Quarter Horse filly. Gate issues have kept her from a consistent record this year in advance of her final start of the season in Sunday&rsquo;s $150,600 Southern California Derby at 400 yards at Los Alamitos.Trained by Jaime Gomez, J Best Boogie was third in the $1.1 million Golden State Million Futurity in November 2020. Earlier this year, J Best Boogie won a minor handicap at 350 yards in July, but was 10th in the Mildred Vessels Handicap in September against top&#45;class fillies and mares and seventh in a division of the Los Alamitos Super Derby trials in October, losing any chance after poor starts.J Best Boogie rebounded to win a division of the Southern California Derby trials on Nov. 28. Ridden by Oscar Peinado, who has the mount on Sunday, J Best Boogie ran 400 yards in 19.78 seconds, earning the fourth&#45;fastest qualifying time in a field of 10.J Best Boogie drew post 8, well to the outside of expected favorite Monopolist, who set the fastest qualifying time of 19.42 seconds in the trials.Trained by James Glenn Jr., for track owner Ed Allred, Monopolist is the most accomplished runner this year in the Southern California Derby field. Monopolist was third in the Los Alamitos Winter Derby in February and second by a nose as the 1&#45;2 favorite in the Governor&rsquo;s Cup Derby in August. He is winless in three stakes appearances since the Pacific Coast Quarter Horse Racing Association Breeders&rsquo; Futurity in October 2020.Monopolist was the fastest qualifier for the PCQHRA Derby in October, but was held out of the final in favor of a start in the time trials for the more lucrative Super Derby a few weeks later. Monopolist finished fourth in a Super Derby trial, and failed to qualify for the final.In the Southern California Derby trials, Monopolist won by a length in a career&#45;best time at 400 yards in his ninth consecutive start at the distance. Monopolist starts from post 2 on Sunday.O Donovan Rossa and Apollitical Hero were first and second in a Southern California Derby trial. O Donovan Rosa, who was timed in 19.82 seconds, was a 31&#45;1 surprise winner and will start in his first major derby of the year. Diego Herrera, who finished tied for second in the Thoroughbred standings at the recently concluded Los Alamitos daytime Thoroughbred meeting and has a background in Quarter Horse racing, has the mount.