A headline on the Chicago White Sox homepage says, "White Sox attempt to make it a banner year." And I was gobsmacked that, as a lifelong and avid baseball fan, it has never occurred to me that that phrase, banner year, may have come from baseball...winning the pennant and thereby hoisting the banner at the stadium. So I went to Word Origins, but there's nothing there. Does anyone know if this is indeed the origin of the phrase, or another site where I can find the etymology?

I took a look in OED and it has the context of "entitled to a banner as a distinction" first showing up in 1840 with "The Whigs...proposed to designate whichever state should give the Harrison ticket the largest majority, as the banner state"
"Banner year" is cited there first as 1931 but in connection with a race horse breeder, not baseball.
I wouldn't think these are conclusively the earliest uses, but it doesn't look like baseball was the start.
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Oh, WO'N, don't you have anything on your mind other than baseball?! I hadn't particularly thought about the usage before, but historically, banners have been carried by those who lead the parade, march or whatever, so I would think that having the banner signifies that you're in the lead.

Welcome aBoard, Charles! Your site seems really cool.