The Cost of 6:5 Blackjack
A natural paying 6:5 instead of 3:2 removes 0.30 units on every player natural—about 1.39 percentage points under a standard frequency model.
The calculation
A player blackjack occurs about 4.75% of initial hands in a conventional full-deck model. The payout reduction is 0.30 betting units, so the screening estimate is 0.0475 × 0.30 = 1.425%. Exact figures vary with deck and rules; roughly 1.39–1.43 percentage points is the practical range.
Session cost
At $25 for 60 hands per hour, 1.39 percentage points adds about $20.85 per hour in theoretical cost: $25 × 60 × 0.0139.
The number is an expectation, not a forecast for one session. A player may not receive any natural during a short visit.
Decision
A 3:2 table with otherwise ordinary rules is normally preferable to a 6:5 table. The payout difference usually overwhelms small benefits such as one fewer deck.
Where this study stops
The Cost of 6:5 Blackjack answers the question defined on this page. It does not predict a session, replace the posted rules or turn a long-run average into a short-term guarantee.