Why Dale Murphy? He's just a crummier Jim Rice, who really didn't deserve his entry.
It's close, real close.
At the end of the day it's personal prejudice. But for that six-year run (1982-1987) he had as good a peak period as your typical HOF member, maybe more. What killed him was his decline, which was more drastic and atypical of what BBWAA voters judge as Hall-worthy.
The likes of Dawson, Nolan Ryan, Ripken and Craig Biggio (ouch) had longer stretches of average quality at the tail end, padding the counting stats. Murphy's decline was so steep and precipitous that it seemed to overshadow all that he accomplished beforehand. So he didn't have the counting stats (400-500 HR) and probably not the monster peak seasons that voters notice in shorter careers (Koufax, Dizzy Dean).
So how does that explain Bruce Sutter? Anyway when I was at Posnanski's site I put myself in the role of a BBWAA voter and figured, what the hell.
As for Rice vs. Murphy... I'd like to see ballpark effects for Fenway and Fulton-County Stadium. It might bridge the gap. Also Murphy's peak seasons were at a key defensive position, confirmed by the five Gold Gloves. Yeah, Gold Gloves are an iffy yardstick (I'd be surprised if Roberto Alomar deserved half of his) but they're not given out to just anyone and Jim Ed never got within sniffing distance of one.
The difference with the stick-it-out guys like Nolan Ryan (Andre Dawson isn't close to the same level) is that being a
decent pitcher still has value. A decline is a decline. If you want to get in purely on peak it had better be like Sandy Koufax style dominance, not just HoF good. David Cone had a HoF good period
In fact, here's a fun comparison:
David Cone, 88-99: 3.15 ERA (131 ERA+) over 2468.0 IP
Tom Glavine, 91-02: 3.15 ERA (134 ERA+) over 2698.2 IP
Practically the same good-not-great peak. A 130s ERA+ is when you can start approaching HoF quality pitching. But the reason why Tom Glavine is (even ignoring 300 wins as I do) an edge HoF case and David Cone isn't is Glavine managed to stick around and at least be serviceable.
87 wasn't really a full season nor was his terrible finale 08. Outside of that he had effectively 1 bad full season in 88; 4 league average 200ish inning seasons in 89, 90, 03, and 07; and 3 pretty good years 04-06. All of that adds up to almost another 2000 innings of career pitching at a still pretty decent clip while Cone could only add on 400 more. In the same way there is a difference between Murphy (4000 good peak plate appearances from 82-87 at a 145 OPS+) and someone else, because he (as you said) fell off a cliff like Cone rather than plateauing nicely like Glavine.
Same reason I don't think Sammy Sosa isn't a HoFer. Outside of that peak (and I don't care about steroids) he was
such and mediocre player. And even in that peak, other than one year, while it was
good it wasn't like Ruth/Bonds/Williams/Gehrig
great.