I only double if I go bust but got a last win smaller than the required bet. You can be sure the odds are not better than 50%, but you can not be sure they are not worse. I believe Playtech and Microgaming has fair doubling, but I do definately not trust a lot of the smaller software providers, and this is not just because of English Harbour. Some slots in pubs or 'slot-casinos' are rigged (Denmark).I have seen how the doubling parameter on one of the slots could be configurated when I watched an operator and he talked openly about it.
After only winning 3 out of 25 doubling attemps in a session I stopped doubling totally. (This was actually at English Habour almost a year ago...) My finger do itch for the doubling button often though, but I at not touching it anymore! (And I am also not touching EH anymore...)
So bascially you get an even bet at best, but you take a risk of getting cheated. English Harbour did not help my confidence, especially since the bug was on the loose for weeks before it was found. Also I am disappointed by the weak reaction to this indicent from casino 'authorities' like it was no big deal.
I think it was in Bob Dancers VP book that it was refered to as 'the sucker bet'.
Given a fair doubling game and you double every time, mathematically it will just increase your variance but have same EV as the game you are playing.
But if you really love doubling (at 50/50 odds, not the high-low games) I would suggest you play Playtech VP where you can half-double. If you are doubling at a software provider which
count doubling as wagering, you should always go for 50% doubles (color) and not 25% doubles (suit) since this will give more wagering.
Explained:
1.You wager 1$ on suit:
you win and have 4$. Total wager is 1$. (25% chance fof this happening)
you lose and have 0$. Total wager is 1$.
2. You wager 1$ on color and repeat if you win:
You win both: You have 4$ and total wager is 3$. (25% chance fof this happening)
You win first, loose second: You have 0$ and total wager is 3$
You loose first: You have 0$ and 1$ wager
Zoozie