Why Bookies Love Multiples

The video shows an example with William Hill.

Manchester United V Crystal Palace - 5.9% over round. If you placed 1000 single bets (hypothetically speaking) on the same game, with the same odds, you can expect to lose £5.90 per £100 staked.

Tottenham V Norwich 5.6% over round. If you placed 1000 single bets (hypothetically speaking) on the same game, with the same odds, you can expect to lose £5.60 per £100 staked.

If you combine these in to a multiple bet, you increase the bookmakers over round to 11.83%. If you placed 1000 bets (hypothetically speaking) on the same double, with the same odds, you can expect to lose £11.83 per £100 staked which is why bookies love them!

Research carried out from this page: -
http://en.wikipedia.org/wiki/Mathematics_of_bookmaking#Overround_on_multiple_bets

William Hill over round 5.9% - Manchester United V Crystal Palace - (5.9 /100) + 1 = 1.059

William Hill over round 5.6% - Tottenham V Norwich - (5.6/ 100) + 1 = 1.056

1.059 x 1.056 x 100 - 100 = Multiple over round 11.83%.