Here is where your "debate" with me falls flat, I have never ever said anything close to this. I said that it is statistically insignificant, that it is well within the margin of error.
I would also posit (though, realistically I haven't got the data handy) that a single player improving their batting average by .050 will most likely NOT lead to "a couple of extra wins for the Blue Jays". Though your assertion that if every player increased their batting average, it would increase the number of wins is, obviously, accurate.
If a guy who usually hits .270 had a year where he hit .320, would you say "he's turned a corner" or "he had a great season"? If a player who usually hits .320 (because those exist, right?) has a year where he hit .270, would you say "he's finished" or "he had a bad year"?
The reason you (assuming you are a rational human being) would say "he had a great season" or "he had a bad year" is because he is still the same player, capable of the same things, but due to a minor statistical anomaly he performed outside of his expected norms.
Also, if *I* were to build a team, batting average would be fairly low on my list of consulted stats, just saying.