Add them up as cards appear — that's the running count (RC). When it's positive, the shoe is still rich in tens and aces: more blackjacks (paid 3:2) and more dealer busts, so counters bet bigger. Negative means the shoe favors the house — bet the minimum. The true count (TC) divides RC by the decks remaining, which is what actually sets your edge.
Learn the full Hi-Lo systemThe blackjack trainer that shows you the odds
Blackjack Odds Trainer is a free practice table that turns every hand into a math lesson. Each Hit, Stand, Double, and Split button shows your real chance of winning and your average dollar result — computed live from the cards actually left in the shoe, not from a lookup table. A coach grades every decision against perfect basic strategy, logs your mistakes with their long-run cost, and lets you drill exactly the hands you keep getting wrong.
The game is the standard US casino setup — six decks, dealer hits soft 17, blackjack pays 3:2, double after split — and every rule can be changed in settings, with the strategy chart adjusting automatically. When you're ready to go deeper, a built-in counting mode teaches the Hi-Lo system hand by hand.
Learn the game
New to the strategy? Start with how to play blackjack, then browse all our blackjack guides — every one backed by exact math from our odds engine.
Free blackjack calculators & tools
Curious whether the pros are for real? Our guide on whether card counting actually works runs the real numbers, and the dealer bust odds page shows exactly which up-cards are the bust cards.
Frequently asked questions
Is the trainer really free?
Yes — completely free, no account, no download, no real-money gambling. It runs in your browser on phone or desktop.
How are the odds calculated?
Every hand, the engine computes the dealer's exact outcome probabilities and your expected value for each action from the actual shoe composition — exhaustive probability math, the same method used to derive basic strategy itself. The full methodology explains exactly how, and you can read who builds this.
Will this make me win at blackjack?
It will make you play perfectly, which cuts the house edge to about 0.5% — the best odds in the casino, but still a house edge. Only card counting flips the edge, and the trainer can teach you that too.
Does it work on my phone?
Yes — it's built mobile-first. The buttons stay pinned to your thumb, and the whole hand fits on one screen.