Thx again for the link. I've given it some thought. I DO think Tarzan is on to something.
1) I see what he means about the key card view. 13 vs 3 is a good example. You want to grab one of those excess 678 cards. And if you stand, if the dealer catches a 678 in one of the next two cards, he very likely doesn't bust.
2) As for tracking this in play, not easy at all. That's for sure. If you're using a main count like HiLo, 678 becomes the side count. As for strategy adjusting in play, I believe you'd look at a ratio such as (Total Remaining)/(678 Box remaining). This would normally be 13/3 = 4.33. If this ratio recedes to 3.50 or less, I could see some interesting strategy adjustments, specifically in playing the 12/13, which is close to the indices anyway.
3) Lastly, I can't practically see a great use for the 678 Box on shoes of 4+ decks. Like a normal count, the fluctuations will be flatter on big shoes. On SD (and even DD), the concentrations change significantly. I can't see it for 6-dks, however.
GL, boys.