The Mariners are the 12th most valuable team in Major League Baseball, according to Forbes, and are about to get more valuable thanks largely to the organization’s upcoming opportunity to opt out of its TV contract. In a new feature Wednesday, the magazine said the Mariners are currently worth $644 million. The team brought in $215 million in revenue and had an operating income of $12.9 million in 2012, according to Forbes. “After the 2015 season, the Mariners can opt out of their current television deal with Root Sports Northwest that is paying an average of $45 million a season,” Forbes said, “for a new deal that may be worth twice as much.”