The only odds that you’ll have to calculate very often at all in draw poker online is the odds of making your draw. However, there are different types of draws in each of the games, and the math behind these draws shows some differences as you move around to the different draw games. Here we’re going to take a look at each type of game (regular five card draw and lowball games) individually and how to calculate the odds needed in each game.
In normal five card draw, you’re usually looking at the odds of making a one-card draw to a straight or a flush. The first thing you have to know is that there are 47 cards left that you don’t know, and each of them are equally likely to be dealt to you on the draw. Next you need to know that a flush draw has nine possible cards that could make your hand, an open-ended straight draw has eight possible cards that can make your straight, and a gut shot straight draw only has four cards that can make your straight. So the odds of making a flush on the draw is 9 out of 47, or 38:9 which is about 4.2:1 against. The chance of making an open-ended straight on the draw is 8 out of 47, or 39:8 which is slightly worse than the chance of making a flush at about 4.9:1 against. Finally, the chance of making a gutshot is 4 out of 47, which is 43:4 or 10.8:1 against, and is quite a long shot.
In lowball games, drawing to more than one card is really bad unless you were given a free draw in the big blind where someone called before the draw but no one raised. If in A-5 lowball you have K5246, then after discarding the King, any Ace or Three will make six-high, a very strong hand. This means you have 8 total cards that can make Six-high and 47 cards that you could draw, so the odds are the same as making an open-ended straight draw in regular five card draw, which was 4.9:1 against. However, you can also make Seven-high, which is a pretty strong hand too. Any Seven will give you Seven-high, and that means you have 12 total cards that can make you a Seven-high or better as your hand. Since there are 47 cards left in the deck, that means there are 35 cards left that do not make your hand a Seven-high or better. That makes your odds against drawing to a strong hand 35:12, or about 2.9:1 against.
