The Rangers are hockey’s discount version of the Knicks, with a native gift for paying way too much for players whose best years can no longer be seen in the rearview mirror. But keeping them from falling into a Knicks-like abyss has been goaltender Henrik Lundqvist, the last line of defense. He’s among the most fundamentally sound goalies in the NHL, capable of taking over a game with or without the help of the men in front of him. Alas, one the league’s best goalies may be ending his New York run next spring, when he becomes a free agent. So it might be wise to visit Madison Square Garden this winter. It could be decades before Rangers fans see another netminder of his caliber.