For perfect basic strategy, the probability of busting when hitting depends on your hand total:

P(bust) = Σ(cards that cause bust) / (cards remaining)

For a hard 16 against dealer 10:
P(bust) = 5/13 ≈ 38.46%
Expected value of hitting = -0.5398
Expected value of standing = -0.5419

Hit by 0.0021 - tiny margins matter over thousands of hands!

Here's the Kelly Criterion for optimal bet sizing:
f* = (bp - q) / b

Where:
f* = fraction of bankroll to bet
b = odds received (1:1 for blackjack)
p = probability of winning (~0.49 with basic strategy)
q = probability of losing (~0.51)

Result: f* = (1×0.49 - 0.51) / 1 = -0.02

Negative result means don't bet at all! The maths doesn't lie.

Casumo's surrender option makes a difference if you use it correctly.

EV = (Probability of Win × Amount Won) - (Probability of Loss × Amount Lost)

With perfect basic strategy: EV = -0.005 × Bet Amount

So for every £10 bet, your expected loss is 5p. Over thousands of hands, this adds up. The house always wins in the long run, but basic strategy minimises your losses compared to playing by gut feeling.