We've probably talked about this before. But it still plays around in my head since I want to write one or two. . maybe three. . separate series myself. When does a detective/police-procedural/historical detective series begin to get long in the tooth? Worn out. Kaput. I'm thinking of the long running series of Ed McBain's 87th Princinct. Or Tony Hillerman's Jim Chee/Joe Leaphorn series. Of cou…