The redoubtable Murray Chass:
Runs batted in are absolute. Home runs are the same wherever you look. Batting average is based on hits and at-bats. None of those statistics have different versions. If we accept new-age statistics, whom do we consult and trust, Baseball-Reference or FanGraphs or some other self-professed expert, Bill James perhaps?
Skipping the bit about WAR (I'm sure you've read enough denunciations of WAR the last few weeks to last 10.7 lifetimes) ... To know anything about Bill James is to know that he does not profess to be an expert. His entire career has been a rejection of the authority of "experts."
The way that baseball was understood 35 years ago, and the way it is understood today, is largely by the interpretations of experts ... The experts all knew, for example, that the prime of a player's career was ages 28 to 32. The experts all knew that when there was a runner on first and no one out, the percentage move was to bunt. The experts all knew that speed was tremendously important, and that the difference between good teams and bad teams was mostly in how they performed in clutch situations. The experts all knew that a good starting pitcher would draw a few thousand extra fans to the game every time he took the mound.
... When I began writing about baseball in 1975, the first thing I did was to say, "Well, I don't know anything. I'm not an expert. But perhaps I could contribute to the conversation by finding a way to take these things that the experts know, and look to see, as best I can, whether they are objectively true."
It turned out in this case that what the experts all knew to be true—that baseball players are in their prime from ages 28 to 32—is just totally, wildly and completely untrue. It doesn't match the data in any way, shape or form. 27-year-old players hit 68% more home runs in the major leagues than do 32 year-old players—thus, saying that 32-year-old players are in their prime and 27-year-old players are not is preposterous.
There was a large community of baseball experts who worked for baseball teams and wrote about baseball, based on this large, shared body of "expertise". A very, very large percentage of the things that the experts all knew to be true turned out, on examination, to be not true at all. It is not true that bunting increases either the number of runs that are scored or the expectation of scoring a single run. It is not true that speed is a key element of successful baseball teams, clutch hitting is either 99 or 100% a chimera, and the identity of the starting pitcher has, except in a very few cases, no detectable impact on the attendance at the game.
When I began to publish articles and later books reporting on research which demonstrated that some of the claims of experts were demonstrably false, this put me at loggerheads with the baseball establishment. There was, in the first fifteen years of my career, a great deal of misunderstanding about what I was doing. People thought—and, indeed, some people still think—that I was trying to supplant the experts, and become an expert myself ... This was never true.
In my early career, people would attack me by pointing out that I had no credentials to be considered an expert. I fell into the habit of saying, "that's right; I don't."
That's taken from a lecture James gave at the University of Kansas titled "Battling Expertise with the Power of Ignorance," the entirety of which can be seen here.
Calling Bill James a "self-professed expert" is like calling the Astros the best team in baseball. It is the opposite of the truth. But what can one expect from an unaccountable blogger, unhindered by the refining influence of editors?