This table: 6 decks, dealer stands on all 17s, double on any two cards, split up to 4 hands, split Aces get one card each. No insurance or surrender.
Every card that leaves the shoe changes what's left. Low cards help the dealer: they have to hit 12 to 16, and small cards let them get there safely. High cards help you: more 10s means the dealer busts more often, and more Aces and 10s means more 3 to 2 blackjacks for you.
Counting is a running tally of that mix. When the cards left are rich in 10s and Aces, you bet more. When they aren't, you bet the minimum. That's the whole edge.
The edge is small, roughly 0.5 to 1.5% with good play, and it assumes you already play each hand correctly (basic strategy). Counting in your head is legal in US casinos, but they can still ask you to leave or cap your bets.
Give every card you see one of three values and add it to your count.
Each deck has 20 low cards and 20 high cards, so a full deck adds up to exactly 0. You'll use that in the full-deck drill.
Press Next card. Say the new count out loud each time, like a dealer would see you doing in your head.
A +6 count means more with fewer cards left. So divide by the decks still in the shoe.
+6 with 3 decks left is a true count of +2. +6 with 1 deck left is +6, a much better spot.
Estimate decks left from the discard tray. The shoe starts with 6 decks, so 2 decks in the tray means 4 left. Rounding to the nearest half deck is close enough, and so is dropping the fraction from the answer.
On this table one betting unit is $10. Use this ramp:
| True count | Units | Bet |
|---|---|---|
| +1 or lower | 1 | $10 |
| +2 | 2 | $20 |
| +3 | 4 | $40 |
| +4 | 6 | $60 |
| +5 or higher | 8 | $80 |
25 cards. Tag each one as fast as you can.
Keys: 1 = +1, 2 = 0, 3 = −1
10 spots. Divide the running count by decks left. Any answer within 1 of the exact value counts, so rounding or dropping the fraction both work.
Dealing…