Blackjack EV by True Count
Drag the true-count slider and watch the expected value of every hand shift as the shoe gets richer in high cards. Flip to count deviations to see exactly which plays change from basic strategy — the cells outlined in gold — and how much EV the deviation buys you. Every number is computed by our own odds engine, per $100 bet, 6-deck H17.
Basic strategy — the same play at every count
How to read it
Each cell is the average dollars won or lost per $100 bet if you play that starting hand optimally against that dealer up-card, at the selected true count. Green is profit, red is loss. At a true count of 0 this is just plain basic strategy. As you slide the count up:
- The whole board drifts greener — a ten-rich shoe helps the player. Each unit of true count is worth roughly +0.5% of EV, which is why a counter raises their bet as the count climbs.
- Stiff hands stop wanting a card. Switch to count deviations and watch 16 vs 10 flip from hit to stand right around a true count of 0, then 15 vs 10, 12 vs 3, and the rest follow as the count rises — the gold-outlined cells.
- Doubles open up against the dealer's strong cards (like 10 vs 10 and 9 vs 7) once the deck is rich enough to land a ten.
What "deviations" are doing here
Basic strategy is the single play that's best at a neutral count. A deviation (or index play) is a different move that becomes correct once the count shifts the deck. In the toggle:
- Basic strategy shows the EV of the always-the-same book play at the selected count.
- With count deviations shows the EV of the best play at that count, and outlines every cell where that best play differs from the book.
The gap between the two modes on an outlined cell is what the deviation earns you. Most are small — which is the honest point: the bulk of a counter's edge comes from bet sizing, with index plays adding a smaller slice. The single most valuable deviation, taking insurance at true count +3, isn't a hit/stand call so it lives off this grid — but it's covered in the deviations guide.
A note on the method (read this if you count)
Every cell's EV is computed exactly by our engine for the modeled shoe — exhaustive recursion over the remaining cards, conditioned on the US peek rule, for 6 decks where the dealer hits soft 17. Two honest caveats worth stating plainly:
- The true-count-to-shoe map is an approximation. Many compositions share the same count, so we use a standard Hi-Lo model that shifts the high-to-low ratio of the remaining cards. It's built to show where and how strategy moves with the count, not to replace a game-specific sim.
- The flip points are composition-dependent, so they can sit a count off the textbook indices. Each cell uses a specific two-card hand (16 is shown as 10-6, for instance), and our engine has small known approximations on razor-thin calls. The classic example is 16 vs 10: the famous "stand at 0" is the generic, composition-independent index — for a two-card 10-6 the real switch is a touch higher, and we land it around +1 to +2. So treat the gold cells as "here's where the math tips," not as a swap-in for memorized index numbers.
Full details on the methodology page; the neutral-count version is the expected value chart, and the canonical index list is in the deviations guide.
Frequently asked questions
How does the true count change strategy?
A higher count means more tens and aces left, which raises the value of standing on stiffs, doubling, and insurance. Plays that are wrong at a neutral count (like standing on 16 vs 10) become correct — those are deviations. Slide the count and toggle deviations to see each one light up.
What's the most valuable deviation?
Taking insurance at a true count of +3 or higher. It's not a hit/stand decision so it isn't on this grid, but it's the single biggest index play — more on the deviations guide.
How much is each true count worth?
Roughly +0.5% of EV per unit of true count. A ~0.5% house-edge game becomes about break-even near +1 and player-favorable beyond, which is when counters raise their bets.
Are the numbers exact?
The EV per hand is exact for the modeled shoe; the true-count-to-composition mapping is a standard Hi-Lo approximation. It's built to show how strategy shifts with the count, not to replace a full game-specific simulation.