How to determine straight potential (plus examples)
When looking at the board, it is sometimes difficult to check whether a straight is possible or not and whether it can be the nuts (see my post on determining the best poker hand and check for poker nuts potential).
Here are some examples to show you how to determine whether a straight is possible. Each example begins with a full Texas Hold’em board and is followed by an explanation.
Example 1a: Unpaired board, no ace
1) How many cards to form a straight?
There’s no pairs or more on the board and there is no ace. Hence exactly five cards on the board can be used to form a straight. We will need to use the rule for five possible straight cards.
2) Is a straight possible?
The board in plain numbers and sorted reads: 2 - 3 - 9 - 11 - 13
Following the rule, we need to calculate high card - middle card; middle card - low card, and the difference between the two remaining cards. That’s:
13-9=4; 9-2=7; 11-3=8
One of the numbers is indeed equal or smaller to four, hence a straight is possible.
3) What is the nut straight?
The only “range” (and therefore the highest) where a straight is possible is between the king and the nine (13-9=4). Since there are two gaps to fill in this range, we would need a queen and a 10 in our pocket to form the nut straight.
Example 1b: Unpaired board, no ace
1) How many cards to form a straight?
The board in plain numbers and sorted reads: 3 - 5 - 8 - 10 - 13
13-8=5; 8-3=5; 10-5=5
No number is smaller or equal to 4. It’s impossible to form a straight with this board.
3) What’s the nut straight?
N/A
Example 2: Unpaired board containing an ace
1) How many cards to form a straight?
Let’s use the same algorithm as above, counting the ace as 14.
14-9=5; 9-4=5; 13-5=8
That shows us that there will be no straight when the ace is counted high. Let’s check for the last possibility, i.e. the ace is counted low.
In this case, we need to take the second lowest card and deduct the ace counted as 1:
5-1=4
Result: A straight is possible when the ace is counted low.
3) What is the nut straight?
Example 3: Paired board, no ace
1) How many cards to form a straight?
There’s a pair of queens on the board, but no ace. We cannot use the queen twice to form a straight, hence we effectively only have four cards to form a straight plus our pocket cards.
2) Is a straight possible?
We need to use the algorithm for four straight cards.
The board in plain numbers and sorted reads: 7 - 8 - 12 - 13
We now need to calculate high card - second lowest card and second highest card - lowest card. That gives us:
13-8=5; 12-7=5
Both numbers are greater than 3, i.e. a straight is not possible with these cards.
3) What’s the nut straight?
N/A
So much for the examples. I hope this will help you to identify straights and ultimately recognizing the best poker hand, or poker nuts.
