SCM, sorry, I was on an overnight and couldnt respond fully. Mike Piazza isnt a Hall of Famer yet because he isnt eligible yet. He'll be a first ballot HOFer for sure. There are 16 former catchers in the HOF. There is only one HOF level catcher way above Posada's league offensively as determined by OPS+ and that's Piazza. Look at this...
Posada 121
Campanella 124
Fisk 117
Carter 115
Ivan Rodriguez 110
Bench 126
Berra 125
Not too shabby. How about your standard accumulation metrics.
Posada's career line was .273/.374/.474, OPS of .848. 1664H, 275HR, 1065RBI, 900R
Bench .267/.342/.476, OPS of .818, 2048H 389HR 1376RBI 1091R
Berra .285/.348/.482, OPS of .830, 2150H 358HR 1430RBI 1175R
Bresnahan .279/.386/.377, OPS of .763, 1252H 26HR 530RBI 682R
Campanella .276/.360/.500, OPS of .860, 1161H 242HR 856RBI 627R
Carter .262/.335/.439, OPS of .774, 2092H 324HR 1225RBI 1025R
Cochrane .320/.419/.478, OPS of .897, 1652H 119HR 832RBI 1041R
Dickey .313/.382/.486, OPS of .868, 1969H 202HR 1209RBI 930R
Ewing .303/.351/.456, OPS of .807, 1129H 71HR 883RBI 1129R
Ferrell .281/.378/.363, OPS of .741, 1692H 28HR 734RBI 687R
Fisk .269/.341/.457, OPS of .798, 2356H 376HR 1330RBI 1276R
Hartnett .297/.370/.489, OPS of .859, 1912H 236HR 1179RBI 867R
Lombardi .306/.358/.460, OPS of .818, 1792H 190HR 990RBI 601R
Schalk- embarrassing selection, OPS career of .656
There are 3 Negro League catchers in the hall without numbers.
Looking at the list, Posada's OPS is higher than all of them aside from Harnett, Dickey, Campanella and Cochrane's. And aside from Cochrane, he is close to all of them. His OPS+ is in the same ballpark or higher than all of them aside from soon to be HOFer, Piazza. Posada would be 5th on this list (6th behind Piazza) in HRs as well. There is no doubt that from a numbers standpoint and postseason standpoint, he's a HOFer. It depends on whether they value the fact that he wasnt the best player at his position aside from one season (2007) and the fact that he was never a middle of the order hitter on this team.