If you run this formula against the odds offered by any bookie you will find that it is just over 1.

If it is 1.1 then that bookie is running a tight ship. If it is around 1.3 then that's typical. 1.5 is getting a bit greedy and 1.7 is downright highway robbery.

So if you're going to do dutch bets then choose a bookie who tends to be closer to 1. Otherwise, you'll have to miss out on more selections introducing more risk.