This is the final weekend in February to take advantage of‘s Derby Prep Double Bonus offer. Opt in and earn a 20% bonus on your gross winnings (up to $100 per day) when you cash a Double that includes any of this weekend’s three Road to the Kentucky Derby series preps: Saturday’s Risen Star (G2) at Fair Grounds and El Camino Real Derby at Golden Gate Fields, and Monday’s Southwest (G3) at Oaklawn Park. Here’s how we’ll play the Rachel Alexandra (G2)/Risen Star Double on Saturday. Rachel Alexandra (Race 11) She’ll be nowhere near her 6-1 morning line price with the announced defection of Chasing Yesterday and possibly Bell’s the One, but #3 SERENGETI EMPRESS (6-1) can rebound in this spot off a poor try in the Breeders’ Cup Juvenile Fillies (G1) when she was out-hustled for the lead and failed to go on. More aggressively handled in her two prior starts in the Pocahontas (G2) and Ellis Park Debutante, she dominated both by a combined margin of more than 30 lengths. There is other speed in the field, but she might prove quickest of them all and will have to be run down. Risen Star (Race 12) Though stuck in an outside post, #14 WAR OF WILL (5-2) faces much of the same cast he dominated in last month’s Lecomte (G3), where he overcame a wide trip to win handsomely by four lengths. Our backup selection is #10 LIMONITE (10-1), who rallied from last in a field of 14 in the slop to finish a good third in the Kentucky Jockey Club (G2) when last seen in November. Has shown a lot more tactical foot in the past, and picks up the savvy Brian Hernandez Jr. for this 1 1/16-mile heat. The play: $10 Double 3 with 10,14 = $20.