I was looking through the posts about G1 made on June 11 (because of Claude's "sooooooo close" comment), when I came across a post by Mav, who had apparently done exactly the same thing I was doing and applied 'horizontal thinking' to one of the posts he had found. His post can be found at http://forums.bungie.org/fanfest/fanfest.pl?read=2258, but I've copied the text here for easier viewing, since it was way down the message index.

I looked over Claude's post, then all of the ones for yesterday (wow, that was a generous hint!), and saw The Tiny Toad's post as seen below.

Not "horizontally" enough?

Well then, what if we put the tic-tac-toe board horizontally, instead of horizontally?

Then we might get

A B C___D E F___G H I
J K L___M N O___P Q R
S T U___V W X___Y Z _

(I did that to force spacing and make it look nicer.)

Following the previous posts on tic-tac-toe matrices and so on and so on, with the glyph symbol possibly standing for the "6th" or middle, right-most column...if we now make the
"top-most" playing
matrix our "leftmost" playing matrix, we'll get "L" as the proper letter. So perhaps this way, G1 = "L."

If this turns out to be right, it's entirely due to the efforts of The Tiny Toad and others.