Last Updated: August 9, 2019

# Twisted 21

## Introduction

Twisted 21 is a blackjack variant that started a field trial at the Rio in Las Vegas on July 7, 2019. Briefly, each player starts with two cards face up and three face down. If the player wants to hit or double down, he chooses which down card to add to his hand. A poker-based side bet is also available based on the poker value of all five cards.

## Rules

The game is based on conventional blackjack rules, which I assume the reader is familiar with. The following are changes made to it, as offered at the Rio.

I wish to emphasize that there is much argument at the game table about what the rules are. Below are my understanding of them, at least as how the game was played on August 8 and 9. I'll address some different interpretations later.

1. A single 52-card deck is used.
2. There are two wagers available:
• Twisted 21 — This is the blackjack wager
• Stud Bonus — This is a side bet based on the poker-value of the player's five cards
3. The Twisted 21 bet is mandatory and the Stud Bonus is optional.
4. After betting, the dealer shall give the player five cards, two face up and three face down. He shall also deal to himself five cards, one face up and four face down.
5. If the dealer has a ten or ace up, he shall check under the first face down card for a blackjack.
6. A winning blackjack pays 6 to 5.
7. If neither player nor dealer has a blackjack, then the player may hit, stand, or double on his first two cards. Please note that splitting is not an option.
8. If the player chooses to hit or double, he should point to one of his face down cards to indicate which one he wants.
9. If the player hit, he may continue to hit, up to a total of a five-card hand.
10. Assuming the player didn't bust, the dealer's shall hit until he reaches a hard 17, soft 18, or five cards.
11. Twisted 21 wagers shall be adjudicated as in standard blackjack.
12. The 21 Stud wager pays according to the player's five cards only, whether or not the player used all of them in his blackjack hand. Below is the 21 Stud pay table, in rank order of the hands. Wins are on a "to one" basis.
13. A "Twisted Stud" is 16 or less points in an otherwise non-paying hand. For counting points, aces count as one. As an example, A-A-2-3-3 would pay 3 to 1 as a two pair, despite having 10 points only.

### Stud Bonus Pay Table

Hand Pays
Royal flush 1000
Straight flush 500
Four of a kind 200
Full house 75
Flush 15
Straight 6
Three of a kind 4
Two pair 3
Jacks or Better 2
Twisted Stud* 20

If these rules were unclear, here is a picture of both sides of the rule card.

## Rule Variants

As mentioned above, every dealer seems to deal the game under different rules. The base game is quite clear but the rack card is very unclear about the Stud Bonus rules and each supervisor seems to have his own interpretation of them. Here are the main points of confusion:

• How is a hand like A-A-2-3-5 scored? It is a high pair or a Twisted Stud? My analysis is based on a Twisted Stud being the lowest ranked hand, but some players have been paid 20-1 for it as a Twisted Stud with hands like this. If the player is paid for the highest qualifying hand and always gets the use of all five cards, then the Stud Bonus bet has a player advantage of over 8%.
• Does the player have to hit into all five cards to get to use them for the Stud Bonus? My rules are based on the player always getting the use of all five, regardless of how the 21 portion of the game played out. However, on Aug 11 at least, the player had to hit into a card to be allowed to use it for Stud Bonus purposes. Yet another question is whether the Stud Bonus is an automatic loss if the player busts.

## Analysis

According to my analysis of the base game, or 21 bet, the house edge is 1.92%.

Following is the return table for the Twisted Stud side bet. Hands are listed in rank order, not pay order. The lower right cell shows a house edge of 2.49%.

### Stud Bonus Return Table

Hand Pays Combinations Probability Return
Royal flush 1000 4 0.000002 0.001539
Straight flush 500 36 0.000014 0.006926
Four of a kind 200 624 0.000240 0.048019
Full house 75 3,744 0.001441 0.108043
Flush 15 5,108 0.001965 0.029481
Straight 6 10,200 0.003925 0.023548
Three of a kind 4 54,912 0.021128 0.084514
Two pair 3 123,552 0.047539 0.142617
Jacks or Better 2 337,920 0.130021 0.260042
Twisted stud 20 7,932 0.003052 0.061040
Loser -1 2,054,928 0.790673 -0.790673
Total   2,598,960 1.000000 -0.024904