Can this be right?

Found an online-video-slot with an unusual double-up after a win feature.
It goes like this:

The machine displays 5 playingcards 1 faceup and 4 face down, you have to pick one of the facedown cards. If the card is lower than the faceup card you lose, if you pick a higher card you win, if the value is the same it's a "push" and you get a new doubleup-round starts.
So far nothing special, it's a very common way to repesent the double-up feature.
What makes this special is at you get to see the faceup card before you decide to try your luck doubling up!
I mean that if the machine plays a fair game and draws 5 random cards then you can choose to double when the shown card is 8 or below and have an average EV of nearly +50% when you chose to double.

2 questions for you all:

A: How do I test if the machine is playing a fair game and does what it looks like it does? How many rounds do I need to confirm that it's fair or unfair?

B: If it turns out to be fair should I also double if the faceup card is 9 or 10 taking into account that even though that bet in itself is -EV it has value to get to the next round for a potentual big advantage.

The only relevant question is, "Why should they offer a fair game?"

One posibility is that the choise to go back and take the win instead of doubling is an error. On the same site I found another video-slot where bets made during the double up feature is countet towards the bonus wagering requirments - opposed to what ther T&C says.

A Zwischenzug is an intermediate move in chess -frequently overlooked by rhe opponent - which instead of moving an attacked piece puts up a threat of its own thereby changing the whole situation.
I still don't know what Gorgon meant by that.

Francis Salmon

in Bavaria.

raswar17,

Some days ago I tried a similar double-up option of an online slot. I doubled only when dealer showed 3 thru 7 (unfortunately never saw a deuce). Here are my modest samples:

1st sample: 56 times, always picking the 2nd card:
- I draw a deuce � 20 times;
3rd card being a deuce � 7 times;
4th card being a deuce � 4 times;
5th card being a deuce � 7 times;
- Return to player 0.82 (2nd card (my choice));
3rd card RTP � 1.46;
4th card RTP � 1.45;
5th card RTP � 1.27;

2nd sample: 30 times, always picking the 3rd card:
- I draw a deuce � 7 times;
2nd card being a deuce � 3 times;
4th card being a deuce � 5 times;
5th card being a deuce � 4 times;
- Return to player 1.00 (3rd card (my choice));
2nd card RTP � 1.43;
4th card RTP � 1.27;
5th card RTP � 1.4;

A very small sample, but results are very suspicious.

Do your testing. One never knows. With the big advantage you are supposed to have, some hundred hands should be enough to verify if the game is random.