The mathematically best first action for every starting hand, generated live by the same engine behind the rankings and the analyzer. Find your hand in the left column, the dealer's upcard along the top.
H — HitS — StandD — DoubleP — SplitR — Surrender
Hard totals
Hard 18 through 21: always stand, against everything.
Soft totals
Pairs
The two rules worth memorizing first: always split aces and 8s; never split 10s or 5s.
How often does the dealer bust?
The chart above makes more sense with this table in mind — you stand on weak totals against 4, 5 and 6 precisely because the dealer breaks most often from those cards.