Churchill Downs goes into the final three days of its spring/summer meet with serious intrigue as the public zeros in on the Single Six jackpot with a carryover of $676,761 into Thursday’s card. The Single Six jackpot, which has been building since May 13, can be emptied only if a single ticket has all six winners. A mandatory payout is scheduled for closing night Saturday if the pot is not taken down Thursday or Friday. Thursday’s sequence encompasses races 3 through 8, including the nominal feature, a $55,500 conditioned allowance for fillies and mares going a mile on the main track. A large and well-matched field poses a challenge: Among the 12 entrants, more than half come in with a last-race Beyer Speed Figure between 72 and 76. Three fillies come in tied for the top last-out Beyer of 76: the consistent Speak Softly and the well-bred Debby d’Oro, both coming off solid efforts at Churchill, and Sierra Squall, off the board in four straight. Speak Softly took six starts to put the pieces together for Jay Em Ess Stable and Paul McGee, winning her maiden by 5 3/4 lengths in December at Fair Grounds. She subsequently came back off a six-month layoff to run a career-best Beyer in an allowance race June 12 at Churchill. Debby d’Oro, the lukewarm 7-2 morning-line favorite, was flattered when another well-bred filly, Walkabout, emerged from Debby d’Oro’s maiden victory to graduate impressively. Debby d’Oro most recently finished third in her first try against winners for trainer William Connelly. Scat Means Go cuts back slightly in distance after finishing fourth in a seven-furlong allowance contested over a sloppy track in May. The Steve Asmussen trainee finished third, beaten 1 1/4 lengths, in the Grade 3 Eight Belles Stakes last year at Churchill. KEY CONTENDERS Speak Softly, by Warrior’s Reward Last 3 Beyers: 76-62-61 ◗ One of three in the field tied for the top last-out Beyer, along with Debby d’Oro and Sierra Squall. ◗ Filly who likes to sit second or third drew post 7 under Robby Albarado, with some other speed outside of her. Debby d’Oro, by Giant’s Causeway Last 3 Beyers: 76-77-69 ◗ Filly is out of the Medaglia d’Oro mare Dashing Debby, who won the J J’s Dream Stakes by 10 1/4 lengths as a juvenile. ◗ Will need to use her speed from the outside post under Miguel Mena. Scat Means Go, by Scat Daddy Last 3 Beyers: 61-60-76 ◗ Owns the field’s top career Beyer with an 84 but has tailed off in recent races. :: Bet Churchill Downs with DRF Bets and get FREE access to this article and all of DRF Plus, including Churchill Downs selections, video, and real-time analysis.