Busting cards are cards that the dealer shows, which may have the effect of bringing him over 21 on a hit. The idea is that if a dealer’s hole card  is a 10-value, then busting cards have values of 4, 5 or 6. 7.

Busting cards make up a part of the basic blackjack strategy since the decision whether to hit or stand is front and center when looking at the dealer’s card.

If  holding a hand that totals 13, look carefully at the dealer’s hand. If they’re holding any of the busting cards (4, 5, or 6) then there’s a very good mathematical chance of them busting on a hit, so rather than hit on your 13 hand, you take proper advantage of the odds and stand.

The dealer may well have a hole card that’s less than 10 in value, over the long run the odds are better that the dealer will bust and you’ll be left holding the pot.