ARLINGTON HEIGHTS, Ill. &ndash; Only 220 yards separate the co-featured sixth and eighth races Sunday at Arlington Park. Both races are restricted to females and are open to second-level allowance runners or $40,000 claimers, with race 6 carded at one mile on Polytrack, race 8 over seven furlongs on Polytrack.\r\nIt&rsquo;s unusual to see two such similar races on a single card, but Arlington apparently did not have a surplus of options for the Sunday program, with just 73 horses entered in nine races.\r\nThere are seven in both of the co-features, but not a standout in either race. The sixth could have Jitterbug Blues as a favorite, which would be reasonable, since Jitterbug Blues won at this same class level and distance when she most recently raced, on July 25. Breaking from the rail that day and rallying from mid-pack, Jitterbug Blues was home by one length over Sweet and Sour Nina, another entrant in Sunday&rsquo;s sixth. Five-year-old Jittterbug Blues, from the barn of trainer Christine Janks, won three straight races during the fall of 2008, and obviously is capable of pairing up peak efforts, and in eight Arlington main-track starts she never has finished worse than third.\r\nStill, improving 3-year-old My Sugar Bear might have a chance at a mild upset. My Sugar Bear finished evenly in two recent turf races, but won an entry-level allowance race at this distance three starts ago in her only Polytrack appearance. She has posted two recent workouts for trainer Dan Peitz, but would have to overcome her rail draw Sunday.\r\nAdhsilver looks like the one to beat in race 8, and won a race here in May against higher-class foes than she faces Sunday. Claimed over the winter by owner Maggi Moss and trainer Tom Amoss, Adhsilver has made her last five starts at five different racetracks, but seems to carry her form with her. Adhsilver finished fourth two races ago at Presque Isle Downs and was third July 14 on the Indiana Downs turf course, and while neither race was among her strongest of the season, Adhsilver had excuses. She broke from the rail both times (and has a much more advantageous outside draw Sunday), and probably is not quite as effective around two turns, which she tried at Indiana, as she is in one-turn races such as Sunday&rsquo;s.\r\nCompetition should come from Sheltered, who is 3 for 3 on Arlington Polytrack, and Pretty Slic Chick, who exits consecutive blowout victories over Illinois-bred allowance foes.