NEW YORK — Josh Hader was talking about the perception of managers, like his own, Joe Espada, who is still the dugout leader of the Houston Astros. They are either smart or stupid, no in between.“It’s a teeter-totter that never stays flat,” Hader, the Astros’ closer, said before batting practice at Yankee Stadium on Tuesday. “It’s leaning one way or the other, and that’s just the way the game is.”Not in the American League West. This is the land of the flat teeter-totter, a moving walkway to nowhere. Someone will disembark in the postseason, but nobody’s in a rush. It’s a division of turtles, seemingly sworn to uphold that old baseball axiom: never get too high or too low.“There’s still a lot of time to go, and I think somebody’s going to pull away,” said Steve Sparks, the Astros’ radio analyst. “Around here, everybody’s hoping it’s Houston, but who’s to say? I mean, nobody really looks that much better than anybody else.”No team in baseball history has won a division in a full season without a winning record. The modern AL West looks eager to take up the challenge.The Los Angeles Angels peaked in March — yes, March — at two games over .500. The Athletics hit their high point in May, at three games over. The Seattle Mariners got all the way to four games over in June, the Texas Rangers to three games over in July and the Astros to three over on August 14.Then they lost six of their next eight at home. With a week of games coming up in New York — three in the Bronx, three in Queens — owner Jim Crane dismissed general manager Dana Brown on Monday. Mediocrity is unacceptable.“The expectation that I have is we’re in the playoffs every year,” Crane said Tuesday. “It’s hard to win (the World Series) every year, but you have to get there.”Brown is the third AL West general manager to lose his job this summer, after Perry Minasian of the Angels on June 26 and David Forst of the A’s on August 7. The managers have all survived, so far, but Dan Wilson’s Mariners have painfully underachieved. At least Skip Schumaker, in his first season as Rangers’ manager, seems secure.