A simple PLUS / MINUS system that I learned a long time ago. As the cards come out, all 2s, 3s, 4s, 5s, & 6s count as a PLUS meaning the more low cards that come out, the more likely the run of cards will consist of FACES & ACES... this is what you want, a run of cards consisting of Faces & Aces because that is what you need to get Blackjack. Do not count the 7s, 8s, 9s. As the Face cards and Aces come out, subtract one for each from your runninng count. The higher your count gets such as +8, the more likely Faces and Aces will make up the next run, and the better your chances are to hit BLACK JACK. Also with a high PLUS count, your chances are higher to go bust on your draw hands with 12s, 13s, 14s, 15s, 16s. This also applies to the dealers chances of going BUST on his draw hands, and also his chances of hitting Blackjack too.

To simplify even further:

2, 3, 4, 5, 6: count as PLUS1,PLUS2,PLUS3, and so on. Higher count means a higher chance of high cards coming.
7, 8, 9: are not counted! So actually you are only counting the five low cards and the five high cards in the deck.
10, J, Q, K, A: Subtract one each from your running count. Plus5 - Plus4 - Plus3 and so on

Your running count should be something like: Plus1 - Plus 2 -Plus 3 - Plus 2 - Plus 1 - Plus 0 - Minus 1 - Minus 2 -Minus 1 etc. When the count gets up to Plus 9 or so, the majority of small cards are gone and this is good. Double your bet but don't get stupid. Blackjack has a fairly low house advantage and a simple system like this can give you better odds at winning. The only casino that ever figured out that I was counting cards at the Blackjack tables was the Pioneer in Laughlin. They told me, "You do not have to leave sir but we will not allow you to play Blackjack anymore." I went next door to the Colorado Belle.