What exactly is an open straight?
By Jerry “Stickman” Stitch
Look at the strategy for just about any video poker game and you will find two different types of straight—an open (or more accurately open-ended) straight and an inside straight. The terms open and inside also apply to straight flushes, which are simply straights consisting of one suit.
Most players, no matter how casual their play may be, know somewhat instinctively that open straights are good and inside straights are not so good. The phase “never draw to an inside straight” is classic old school poker advice.
According to the Poker Dictionary, available at pokerzone.com, an open-ended straight is defined as follows:
“A sequence of four cards of consecutive rank in which there are two possible card ranks that will complete a straight; as opposed to a one.”
Using this definition a 5, 6, 7 and 8 is an open straight. The 2, 3, 4 and 5 is also an open straight as is the 10, jack, queen and king. This is true because the straight can be completed by drawing a card on either end of the sequence. In the first example a 4 or a 9 would complete the five-card straight. In the second example an ace or 6 would complete the five-card sequence. And, in the last example, a 9 or an ace would complete the five-card sequence.
Many video poker players think of an open straight as any sequence of cards without a gap. They might consider an ace, 2, 3 and 4 as an open straight.
It is not.
It is true that this is a four-card sequence that does not contain a gap, but it can only be completed by drawing a card at one end of the sequence—a 5. For this reason, this sequence is considered an inside straight. Rather than thinking of an open four-card straight (or straight flush) as a sequence of cards without a gap, it is better to think of it as a sequence of cards that can be completed at either end of the sequence. Anything else is an inside straight.
What about three-card straights?
The same rules apply. Just because the three cards are in sequence does not automatically qualify the hand as an open straight (flush). A hand containing a 5, 6 and 7 would be an open straight (flush). It can be filled by drawing the 3 and 4, the 8 and 9 or the 4 and 8. In other words, it can be completed by drawing two cards on either end, or one on each end.
A hand containing a 2, 3 and 4 would not be an open straight (flush). It can be completed by drawing a 5 and 6, and by drawing an ace and 5, but there is only one slot at the low end of the sequence—the ace.
The same rules apply to a 2-card straight (flush). A hand containing a 5 and 6 is an open straight (flush) because it can be completed by drawing the next or previous three cards in the sequence. Specifically, drawing a 2, 3 and 4 or a 7, 8 and 9 will complete the straight (flush). Drawing a 3, 4 and 7 or a 4, 7 and 8 will also complete the straight (flush).
What about a hand containing a 3 and 4? It can be completed by drawing the 5, 6, and 7. It cannot be completed by drawing the three lower cards in sequence, however, and only the ace and two slots are open.
Hopefully the above explanations and examples are clear to you. Rather than to define an open straight (flush) as a series of cards in sequence, it is much better to define an open straight (flush) as a hand that has a series of cards in sequence AND can be completed by filling either end with the total number of slots remaining after discard.
The above definition works fine as long as the game being played is a standard (non-wild card). If playing a wild card game such as deuces wild, the definition of an open straight (flush) has an additional requirement. That requirement is a wild card cannot be used to fill the gap and create an open straight (flush). For example, in deuces wild a hand containing a 2, 6, 7 and 8 is considered an open straight (flush). However, a hand containing a 2, 5, 7 and 8 is not considered an open straight (flush) because the missing 6 cannot be filled by a wild card to be considered an open straight (flush).
In order to make video poker play as profitable as possible, dealt hands must be interpreted properly. Improperly determining an inside straight (flush) as an open straight (flush) will dramatically reduce the expected return. Take the time to determine that what you are seeing is actually what you think it is. That will pay dividends in the long run.
How Would You Play These Hands?
Open and inside straights and straight flushes were the topics of this month’s article. Here are some hands that feature open and inside straights/straight flushes.
These hands are played on a full-pay (9-for-1 for a full house and 6-for-1 for a flush) Jacks or Better game with the max credits of five. The first hand is: 2♦A♦4♦A♥5♦
This hand contains a high pair (A♦A♥), and four of an inside straight flush (2♦A♦4♦5♦). Much more often than not saving a high pair is the preferred play, but in this case we also have a very powerful straight flush—even though it is an inside straight flush so only one card will complete the hand.
Saving the high pair returns 7.683 credits. Saving the four card inside straight flush returns 11.915 credits—50 percent more than the high pair and the much better choice.
Let’s try another fairly easy one: 2♦3♦4♦5♦A♥
This hand contains a straight (2♦3♦4♦5♦A♥), and four of an open straight flush (2♦3♦4♦5♦). Four of an open straight flush is a very powerful hand as it can be filled from either end, and if filled, returns 50-for-1. Is that enough to offset the sure 4-for-1 return for the pat straight?
Saving the four of an open straight flush returns 17.234 credits on average—not quite enough to overtake the 20 credit return for the straight.
The next hand is a little closer: 3♦4♦5♦Q♣J♣
This hand has two of a royal flush (Q♣J♣) and three of an open straight flush (3♦4♦5♦). The two of a royal are the strongest there are. Does three of an open straight flush have what it takes to overcome them?
Saving two of a royal returns 3.123 credits. Saving three of an open straight flush—while still an overall losing hand in the long run—returns 3.150, making it the better hand to save.
Let’s modify the last hand slightly, changing the three card open straight flush into a three card inside straight flush. The modified hand is: 2♦3♦4♦Q♣J♣
Notice that the three cards of the straight flush are in sequence (2♦3♦4♦). It is not an open straight flush, however, because it cannot be filled by two cards on either end. The 5 and 6 of diamonds will fill it on the high end, but the ace of diamonds is the only card possible on the low end.
Will this change make a difference in the preferred hold?
Saving the two of a royal flush still returns 3.123 credits. However, saving the three of an inside straight flush returns just 2.669 credits. Saving for the royal is a better choice.
Now how about looking at some hands in a full pay deuces wild game? This is a great game to play—if you can find it. It returns 100.76 percent with proper play. The pay table looks like this for five credits played:
Royal Flush (no wild cards) 4000
4 Deuces 1000
Wild Royal Flush 125
5 Of a Kind 75
Straight Flush 45
4 Of a Kind 25
Full House 15
3 Of a Kind 5
First hand: 5♣6♣7♣2♥Q♦
This hand contains a wild card (2♥), four of an open straight flush (5♣6♣7♣2♥), and two of a royal flush (2♥Q♦).
Saving the lone wild card returns 5.18 credits on average while saving two of a royal flush returns just 4.63 credits. The obvious best save—four of an open straight flush returns 11.27 credits.
Now let’s look at a slightly different hand. Let’s change the 6♣ to a 6♥. This new hand is: 5♣6♥7♣2♥Q♦
In this case we no longer have a four card open straight flush save. Instead we have a four card open straight (5♣6♥7♣2♥), a three card inside straight flush (5♣7♣2♥), a two card royal flush (2♥Q♦), and a lone wild card (2♥).
Saving the four card open straight returns 5.000 credits. Saving the three card inside straight flush returns 4.921 credits. Saving the two card royal flush returns 4.635 credits and saving the lone wild card returns 5.167 credits. The lone wild card is the best save for this hand.
Now, let’s slightly change the hand one more time by making the 5♣ a 5♥, and making the 6♥ a 6♣. The modified hand is: 5♥6♣7♣2♥Q♦
This hand now contains a four card open straight (5♥6♣7♣2♥), a three card open straight flush (6♣7♣2♥), a two card royal flush (2♥Q♦), and a lone wild card. Does this change matter?
Saving the four card open straight still returns 5.000 credits. Saving the two card royal flush still returns 4.635 credits. Saving the lone wild card still returns 5.167 credits. However, saving the three card open straight flush now returns 5.402 credits, making it the preferred save. Let’s look at one final hand for full-pay deuces wild: 4♦5♦6♣8♦Q♥
This hand contains only two viable choices—four of an inside straight (4♦5♦6♣8♦) and three of an inside straight flush (4♦5♦8♦). This hand is interesting in that it is one of very few hands where both of these possible saves have exactly the same expected return—1.702 credits. It does not matter which of the two possible saves you make. In the long run you will have the same return.