Enter the dealer's upcard and your own hand, and it names the single play with the highest expected value.
Set these to match the table you are sitting at. The verdict and all three charts recalculate together.
The dark row across the top is the dealer; the column down the side is your hand. The cell you are in is outlined.
Almost every blackjack chart on the internet is a picture file. A picture does not know the rules of the table you are sitting at.
Change S17/H17, DAS or surrender and the verdict plus all three charts are recomputed. Hard 16 against a dealer 10 is R with surrender on and H with it off.
Rather than just handing you an answer, it outlines the matching cell below. The chart becomes familiar as you use it, until you no longer need the tool.
Every chart assumes two cards. Once you have hit, double and surrender are gone — and the fallback play is shown automatically.
The key hard, soft and pair cells were checked one by one against widely published 4–8 deck charts, across every rule combination, and all of them agree.