The current J.D. Martinez fever among Red Sox fans reminds me of the clamor for Adrian Gonzalez seven off-seasons ago.
Compare the lines for Martinez today and Gonzalez in December 2010:
AG 7 seasons, 3631 PA, .284/.368/.507/.875, OPS+ 137, 19.6 bWAR, 18.3 fWAR
JM 7 seasons, 3118 PA, .285/.342/.514/.857, OPS+ 130, 13.7 bWAR, 13.5 fWAR
Of course, Gonzalez was acquired via trade, not free agency. Martinez is about 20 months older today than Gonzalez was on the day of the trade.