Comparing Short Deck to Full Deck

Disclaimer: This article might seem dry and boring. However, before we get to the more interesting topics of Short Deck it is imperative that we set the proper groundwork and examine the implications of playing with the truncated deck. So grab a cup of Joe if you must and let’s get to it.

In a normal 52-card deck there are 1,326 combinations of starting hands. With a short 36-card deck the number of hand combinations is reduced to 630 which is a reduction of greater than 50 percent. Thus, you are slightly more than twice as likely to be dealt aces or any other particular hand.

When you are dealt a pocket pair, your odds or making a set or better increase by around 50 percent. In hold’em, your odds are approximately 12 percent whereas in Short Deck it is around 18 percent.

When you are not dealt a pocket pair your odds of flopping either trips or two pair is slightly double than it is in traditional hold’em.

Flopped straights are much more common, any hand capable is typically more than three times as likely in Short Deck. For example, J-10 has a 1.2 percent probability in hold’em but a 4.2 percent chance in Short Deck. A-J has probabilities of .3 percent and 1.1 percent respectively. The reason why straights are so much more prevalent is because when you hold J-10 it is more likely due to removal that the flop will be cards other than jacks and tens and due to the short deck there are fewer of these other cards.

Drawing odds are also increased significantly with each out worth about 50 percent more than with a full deck. In traditional hold’em an eight-out draw has around a 31.4 percent probability coming in, however in Short Deck it is 45.6 percent.

Flushes are harder to hit because four flush cards have been removed from the deck. Flush draws only have five outs instead of nine thus they are harder to hit. Mathematically, it is harder to make a flush than a full house which is why the hand rankings have been revised.

Sets still have seven outs on the flop and ten on the turn to make a full house or quads; however, if there is a flush draw out there some of those outs may be dirty.
Open-ended straight and flush draws and a whopping 59 percent chance to complete by the river.

The chart below specifies the probabilities depending on your estimated outs:

Outs Two Cards to Go One Card to Go
1 6% 3%
2 13% 7%
3 19% 10%
4 (Two Pair to Full House, Gutshot Straight) 25% 13%
5 (Flush Draw) 30% 17%
6 36% 20%
7 41% 23%
8 (OESD, Flush Draw w/ Gutshot Straight) 46% 27%
9 50% 30%
10 55% 33%
11 (OESD w/ Flush Draw) 59% 37%
12 63% 40%
13 67% 43%
14 71% 47%

• As previously mentioned, sets have seven outs on the flop and ten on the turn to improve and over the course of two cards this will occur around 48 percent of the time. With one card to come the probability is 33 percent. These two facts are highly relevant for a few reasons. The first is that top set versus a flopped straight is almost a virtual 50-50 coin flip. The second is that even if you know your opponent has a straight on the turn and bets the pot the 2:1 odds against you making your hand exactly match those offered to you by the pot.

• In hold’em the Rules of 4 and 2 used to estimate the approximate probabilities that your draws will come in on the flop and turn respectively. For example, if you have eight outs the Rule of 4 indicates that you have approximately a 32 percent (4 × 8) chance of completing your draw with two cards to come. Compared with the actual probability of 31.4 percent this is a fairly good estimate and in practice very useful to your decision making. In Short Deck using Rules of 6 and 3 will closely approximate your probabilities enough to adequately aid your decisions.

• In Short Deck the final board will be paired close to 50 percent of the time and when it is not a straight is always possible.

• Still awake? Just checking.

• A major consequence of the above fact is that position is worth much more in Short Deck when compared with hold’em. In hold’em there are many more situations where the turn and river will not change hand values much, however, this is the case much less often in Short Deck. However, in Six Plus Hold’em where trips beat straights, position is not nearly as vital because when you flop trips or better your opponents are either drawing slim or dead.

• Big pairs such as K-K and Q-Q will have to deal with the issue of an over card to their pair a greater percentage of the time. Unimproved kings will have to deal with an ace on board approximately 28.1 percent of the time compared with 20.7 percent in hold’em. For pocket queens the percentages are 41.7 percent and 34.3 percent respectively. And in Short Deck, overpairs to the board are not as strong because you will more often be up against straights, sets, two pairs, and draws that have a lot of equity.

• J-10 suited is a premium starting hand in Short Deck because every straight it makes is the nuts and it has tremendous reach. It will flop two pair or better, a flush draw, or straight draw with at least four outs approximately 63.4 percent of the time. Let’s examine how often we would expect to make either a straight or a flush in Short Deck compared with hold’em. For the sake of simplicity we will ignore the small percentage of time that you will flop both a straight and flush draw.

Short Deck Full Deck
OESD 18.8% 45.6% 8.6% OESD 9.6% 31.5% 3.0%
Gutshot 29.2% 24.5% 7.2% Gutshot 16.6% 16.5% 2.7%
Flush Draw 9.5% 30.1% 2.9% Flush Draw 10.9% 35.0% 3.8%
18.6% 9.6%
Flopped Flush 0.5% Flopped Flush 0.8%
Flopped Straight 4.2% Flopped Straight 1.3%
23.3% 11.7%

As you can see you are more than twice as likely to end up with either a straight or a flush and the ramifications are even more pronounced when you consider that flushes beat full houses in Short Deck. When including combination straight and flush draws, the J-10 suited will make a flush or a straight approximately 25 percent of the time when it sees all five board cards.

In Short Deck starting hands that can make straights are very valuable as it is easier to make a straight than trips, however in the Triton Poker hand rankings straights beat trips.

Thus in essence they are a “great bargain” and many of them are very strong hands even when they are not suited. However, some are much stronger than others and in the next issue we will analyze the various holdings and introduce power ratings based upon their straight making ability. ♠

Kevin Haney is a former actuary of MetLife but left the corporate job to focus on his passions for poker and fitness. He is co-owner of Elite Fitness Club in Oceanport, NJ and is a certified personal trainer. With regards to poker he got his start way back in 2003 and particularly enjoys taking new players interested in mixed games under his wing and quickly making them proficient in all variants. His new mixed games website www.countingouts.com is a great starting resource for a plethora of games ranging from the traditional to the exotic. He can be reached at [email protected].