Does anybody know why the index number for 12 vs. 5 is lower (more negative) than 12 vs. 6? For hi lo, my chart says that the index number for 12 vs. 5 is -2, and 12 vs. 6 is negative one. I'd think that you'd need more low cards in the deck in order to justify hitting vs a 6 than against a 5. also, a lower number follows the pattern

12 vs. 2 +3
12 vs. 3 +2
12 vs. 4 0
12 vs. 5 -2 (i've seen negative one here)
12 vs. 6 -1 ? (i've seen 0 here for hi lo as well)

Can anybody explain this?