The Mariners have spent a decent chunk of the season living in a weird space between frustrating and dangerous. You know the feeling by now. The record hasn’t always screamed contender. And yet, when ESPN recently looked at which teams could stand in the way of a Dodgers three-peat, Seattle made the cut. It says something about how the rest of baseball views Seattle’s ceiling when you strip away the daily irritation of watching a team stumble through individual games to start the season. The Mariners were not mentioned as a sleeper. ESPN’s case was built around the idea that a playoff version of this roster has the kind of pitching depth, star power and October structure that could make Seattle a real problem in a World Series matchup against Los Angeles. The company makes it even more interesting. ESPN’s list included the Braves, Yankees, Cubs, Pirates, and Phillies. That’s a fascinating group for a few reasons, but especially because the Phillies were included despite the start they’ve had.…