Blackjack Strategy API

Blackjack maths as an API, computed locally and deterministically and exactly — the hand value, the textbook basic-strategy play and the dealer odds, the numbers that hold the house edge to half a percent. The hand-value endpoint scores a hand the way the table does: aces count 11 unless that busts, then 1, so it reports the best total, whether it is soft (an ace still counting 11, safe to hit) or hard, whether it busts, and whether two cards make a blackjack. The strategy endpoint gives the correct basic-strategy action — hit, stand, double or split — for any hand against the dealer's upcard, for the standard 4-to-8-deck game where the dealer stands on soft 17 with double-after-split allowed: 16 against a 10 hits, a pair of 8s always splits, soft 18 doubles against a 6 but hits against a 9, and 11 doubles against everything but an ace. The dealer-odds endpoint gives the dealer's bust probability by upcard — a 5 or 6 busts about 42 % of the time, an ace only 12 % — the reason you stand on stiffs against weak upcards. Everything is computed locally and deterministically, so it is instant and exact. Ideal for blackjack trainers and strategy apps, card-game and casino-game tools, learning aids, and game back-ends. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 compute endpoints. Educational — not betting advice; the house always keeps an edge.