Using only Two indexes will work?

I've been experimenting by using only two indexes playing 6:5 single deck game and it seems to work for me so far.
Using the 10-Count as follows: 16 vs. T and 12 vs. 2 and 3 Hit if negative, Stand if positive. Get Insurance is count >=+4
I know, the game I play, Single Deck 6:5, very horrible setup but I'm managing to win over a very long period of time with a spread of 5:1. I'm playing in this game for over 3 years now on average of about 20 hours per weekend. How you guys would try to improve short of finding a better game? This game is just 5 minutes from where I live. So taking that in consideration how should I improve my game?

M