# Blackjack Online Odds Explained

Blackjack Online is a probably the only casino game where skill and chance have a fairly equal weight. Therefore, understanding how odds can work in your favor is crucial.

Before starting out, let’s do a quick brushing-up of basic probability calculations from Statistics 101. The probability of an event is the number of ways the event can occur, divided by the total possible outcomes. The odds of drawing an Ace from a standard 52 deck will, then, be 4/52, or 7.69%, while the probability of getting the Ace of spades will be 1/52 = 1.92%.

The number of decks in the shoe depends on the casino’s policies. As a rule, the fewer decks, the better you can compute the odds and bend them in your favor. Let us analyze the case of the online blackjack online dealer showing an Ace in a five seat game, with one and an infinite number of decks in the shoe. Furthermore, for the beauty of the example, let us also assume that you are sitting in the fifth position and the other four players show a ten-valued card each. You are holding a hard 19, quite a strong pair that gives you a fairly good chance at winning the pot.

Case A: one deck in the shoe

Out of the 52 cards in the deck, eleven are facing up and you can analyze them. The odds of the online blackjack dealer having a ten in the hole card will be eleven (sixteen ten-valued cards, minus the five on the table) out of 41 (52 minus the ones facing up), or a little less than 27%.

Case B: infinite number of decks

Since there are an infinite number of decks in the shoe, there is also an infinity of ten-valued cards left. Therefore, the ones you can see on the table won’t influence the outcome and the probability of the dealer having a ten is simply the 4:13 ratio of tens in the deck, or around 30.8%.

The difference of roughly 4% between cases A and B is much higher than the average edge the online blackjack online casino has over the player, which is of less than 1%. The bad news is that regular online blackjack games are played with six to eight decks in the virtual shoe (which give the odds of the dealer holding a ten in the above example of 30.2-30.4%). The good news, on the other hand, is that, since the shoe isn’t infinite, computing odds on the fly and making educated decisions isn’t impossible. You can build an Excel spreadsheet and have it compute odds in certain scenarios. Doing the Math is worth it—the difference of 0.4-0.6% outlined here will definitely pay up in the long run.