I just want to avoid the spread of a common misconception, namely that Basic Strategy playing decisions are the same as playing decisions for a true count of zero. While very close, this is technically not true. Basic Strategy decisions are correct for the first two player cards dealt off the top of the deck/shoe. There is a subtle difference in that, while the true count off the top of the deck/shoe is zero, it may no longer be zero when the first playing decision is made.
Consider the case of playing 16 vs T using HiLo (no surrender). The multi-deck index is to stand at any count greater than or equal to zero, yet Basic Strategy says to hit. How can this be? If we look at all of the possible ways to have 16 vs T with 2 player cards, we have T,6 and 9,7 (8,8 is a separate decision). Combined with the dealer's T, we can see that the count will always be negative. So the decision to hit does not contradict the index.
A similar case of 12 vs 4 using HiLo is left as an exercise.