Toby Hyde is reviewing the Mets’ system position by position. Today: second base, which once again is shaping up to be an open competition in Spring Training. There are some interesting-if-flawed names in the minors — Jordany Valdespin, Reese Havens — to go along with the interesting-if-flawed candidates in the majors. But Toby will tell you all about all those dudes over there.