SEATTLE — At some point it’s going to end. The feeling of imminent failure among some Seattle fans is going to manifest on the field and this unexpected season is going to start crumbling until it’s just like each of the previous seasons since the Mariners last made the playoffs in 2001. It has to, right? That feeling is what nearly two decades without postseason baseball has created in the Pacific Northwest. While there is genuine excitement for what Seattle accomplished in the first 3 1/2 months of the season there’s also a sense of dread among the most fatalistic fans who have seen promising seasons go south before, and it won’t go away until the Mariners officially end the longest current postseason drought in any of the four major pro sports. Lucky for the doubters, this team is showing the type of resilience needed to do just that. “I think the thing I’m most proud of, I guess, with this group is the ability for them to be as tight as they are,” Seattle manager Scott Servais said.