The question was asked by
As you can see, Junior the league average was a distant thing for the first 11 years of his career, but for his year-by-year and his lifetime average. These last 10 years he's flirted with, and failed to meet, mediocrity most years.
The specific answer to Steve's question is, Griffey, Jr. was a lifetime .299 hitter after the 1998, his first ten seasons. He is now sitting at .285. He's taken a 14-point hit, so the damage is worse than Steve thought.
As is my wont, I have shown the dividing line between the modern and steroid eras of baseball, the start of which, and I propose a universal adoption of this standard, is the season Brady Anderson first hit 50 home runs. I don't think Anderson ever tested positive for steroids, but look at his lifetime power numbers and I think you'll agree that this is the demarcation point.