Greg Spira's Pitch to the Score
Regarding Jack Morris:
The conclusion is fairly obvious. Jack's records are clearly the result of how many runs are scored when he pitches and how many runs he allows. Thus, his ERA (or RA), along with his innings pitched, are a perfectly accurate measure of how valuable Jack has been to his teams.
And the article conclusion:
[T]he evidence presented does suggest that anytime a pitcher is tagged with a reputation that indicates that his (adjusted) ERA is not indicative of his pitcher contributions, we should take it with an extremely large grain of salt, and not believe it unless there is clear evidence that it is true.
Joe Sheehan's Jack Morris Project:
What we now know is that instead of "pitching to the score," as his supporters claim he did, Morris actually put his team behind in 344 of his 527 career starts. All told, Morris blew 136 leads in 527 starts, or about one every four times out, and that's using a generous definition of "blown lead." Take this with a grain of salt, but having gone through the man's career, I wish I had tracked the number of times Morris turned a lead into a tie. He would quite often turn 2-0 into 2-2, then 4-2 into 4-4, before leaving with a 5-4 lead. If I lose my mind at some point, perhaps I'll go back through his career and track those occurrences.
As I said, I don't know what the performance record of someone who had successfully pitched to the score would look like. I am certain, though, that for a pitcher to build his Hall of Fame case on the notion that he did such a thing, he couldn't have put his team behind in nearly two-thirds of his career starts, and he couldn't have blown leads once a month throughout his career.