Terrific work! This is obviously optimistic in that a player who is bad enough to play himself out of the league or suffer a career-ending injury isn't around anymore to bring the average down. This is the flaw in the data. The data is biased for the precise reason you state. The original post was a nice idea and FK definitely put some time into this. I would've tweaked it by including all seasons, even for players who were no longer playing. So, for a player who was retired at his age 38 season, I would count him as a "0" (Zero) for that year instead of not counting him at all. Also, I would've used OPS+ instead of OPS since we're comparing seasons that, in some cases, are decades apart. Mantle's 1968 season, as discussed, was an extremely productive season when judged in its proper diminished offense context. But the raw unadjusted numbers for Mantle's '68, unfairly, underrepresent their true value. And yes, Roy White was a beast in his prime. A true star. Extremely underappreciated. He starred during perhaps the Yankees worst era -- when they were a team with no playoff aspirations playing in a crumbling stadium and in a city now dominated by the Mets, whose fans still hadn't come down from their Miracle hangover.