You’d think online casinos would provide rich pickings for card counters. After all, you can play single-deck games with very slim house margins, you have tons of time to keep a count and there’s no ‘eye in the sky’ to watch you. It sounds like easy money, but it’s not, alas...

Online casinos are useless for card counters. This is because no matter how many decks are used to randomise the cards, the deck is effectively shuffled after one hand is played out. Even in the rare case where single-deck blackjack is being dealt, the player can occupy only one box. This means that the best a player can see is three, maybe four, cards before they decide whether to hit or not. And since you’re playing only one hand before you shuffle, there’s no way of even varying your bet stake.

Where four- or six-deck games are advertised, you’ll still find the decks are shuffled after only one hand is played. The difference is that you might be able to play up to three boxes yourself. Even so, the true count from those few cards is next to meaningless.

The only way to improve your edge in an online casino is to pick the game with the best odds.To calculate the edge in a blackjack game, check out http://wizardofodds.com/games/ blackjack/bjhouseedgecalc.html where you can specify the particular game rules to find the exact house edge. The best I’ve found is single-deck blackjack at harrods-casino.com, which hits soft 17s, allows double downs on any two cards and allows up to one split. This gives the house a tiny edge of 0.0736 per cent. It also has a four-deck game that allows surrender – unusually generous for an online game.