Basis21: Blackjack Trainer

Basis21 teaches you the mathematically correct play for every blackjack
hand — not general tips, but the exact, EV-optimal decision for the
specific rules at your table.

HOW IT WORKS
• Pick your casino's exact rule set (deck count, dealer soft-17
behavior, doubling restrictions, surrender availability, and more) —
Basis21 ships with presets for major casinos and lets you fine-tune
any rule.
• Drill: get dealt random hands and choose your play. Basis21 grades
every decision instantly, shows the correct action and the EV
difference if you got it wrong — and with Continue after Hit, you can
draw a real card and play the hand one move further instead of
stopping at the first decision.
• Strategy Chart: browse the full basic-strategy chart for your rule
profile, with an EV breakdown behind every cell so you understand why
it's correct — not just what to memorize.
• Compare: heading to a different casino? Put your usual rules side by
side with the table you're about to play — see exactly how many hands
change, and by how much, before you sit down.
• Track your accuracy over time, see exactly which situations you're
weakest on, and drill them directly — with focus modes for your
weakest spots, mistakes you've made before, and the genuine close-call
hands where the correct play is a coin flip.

WHY BASIS21
Off-the-shelf strategy charts assume one generic rule set. Real tables
vary — deck count, dealer soft-17 behavior, doubling restrictions, and
surrender rules all shift the correct play. Basis21 computes strategy
from first principles for your exact rules, so what you drill is what
you should actually do at the table.

Basis21 is a training tool for education and entertainment. It does not
involve real-money wagering, betting, or gambling of any kind, and
correct basic strategy narrows the house edge — it does not guarantee
winning.