Well i know you win more hands if you just hit vs doubling. I think you knew that!
I actually got this theory, from the infamous 11vX hand, where my index is -6.
It always, and I mean always seemed, that when there was a
deck or less to be played in a 2D game, and my TC reached -7 or less, which prompted me to hit, opposed to doubling, it would cost me dearly.
This lead me to the conclusion, that all TCs are'nt equal. Doubling the 11vX @-6 with 1/2 deck remaining, is a much better bet(imo) than doubling it with the same TC, with lets say a deck and a half remaining.
I know, I know what your going to say, but trust me when i say theres some kind of 'floating advantage' that's taking effect, with particular hands at different deck levels and the number of decks in play.
OK, you can call me crazy now