When considering stadium sites in Tampa Bay for the Rays, there is one important factor that cannot be overlooked:The perfect site does not exist.Downtown Tampa would be ideal, but adequate land and financing will be hard to come by. Downtown St. Petersburg has room and funding mechanisms, but a rotten track record with attendance. Other locations have their upsides, but most of them have more downsides.So why is it important to point this out?Because it adds a certain wild-card element to the chase. If one site does not stand clearly above the rest, then the final choice could hinge on the details involved.And that brings us to Derby Lane, a site rarely listed among the favorites but increasingly appealing in some circles. It may eventually be Pinellas County's best chance of keeping the Rays from packing up and crossing a bridge into Hillsborough County.That doesn't make Derby Lane a frontrunner today. Downtown Tampa remains the favored choice for the Rays, even if the team's options have been limited by Jeff Vinik's expanding empire.But if the cost is too high in Tampa, Derby Lane could be an intriguing fallback because of its proximity to Hillsborough. Which is the same reason that a Gandy Boulevard site was once the leading contender, when the Pinellas Sports Authority was shopping for stadium land in the early 1980s.Back then, local officials were looking across the street from Derby Lane, where the Brighton Bay apartment complexes were eventually built. Today, Derby Lane's 130 acres could be in play because of the declining appeal of greyhound racing.So would Derby Lane's owners sell?In the right situation, yes.Derby Lane president Richard Winning, who is the great-grandson of the track's original owner, says his current focus is expanding the gaming options beyond a poker room and pari-mutuel wagering. He said he hasn't talked to the Rays about selling but has heard enough chatter to have considered it.One thing that could hasten the conversation is if the Florida Legislature passes a decoupling bill in the spring. Decoupling would allow pari-mutuel facilities to continue offering poker — and perhaps other games — even if they no longer have dog or horse racing. In that scenario, the dog track could make way for a baseball stadium while Derby Lane could continue its profitable poker room.(How Major League Baseball would feel about that is another question entirely.)Decoupling had some momentum in the Florida Senate last year but died in appropriations. State Sen. Jack Latvala, R-Clearwater, who has publicly supported Derby Lane as a potential stadium site, is now the chairman of the appropriations committee and said he expects decoupling to be raised in the upcoming legislative session.Another potential advantage — or stumbling block — would be the city of St. Petersburg's role. Mayor Rick Kriseman and the City Council favor redevelopment of the Tropicana Field site with a new stadium built on the eastern edge. But would they throw their support, and building funds, behind a Derby Lane effort, if it meant keeping the Rays in Pinellas County?A possible enticement would be annexing the Derby Lane property, which currently sits just outside the city's border. It would technically keep the Rays in St. Petersburg, while also increasing the city's tax base if hotels and other businesses were built around the stadium.The idea involves a lot of moving pieces and may prove to be too farfetched.But, then again, how enthusiastic are the Rays going to be about recommitting themselves to downtown St. Petersburg when it has become obvious that Hillsborough fans are not driving that far?And will Rays owner Stu Sternberg be willing to spend a boatload of his own money if there is little political clout to fund a stadium in downtown Tampa? Derby Lane is still a long shot. And it's far from being a perfect site.But which site is?