Originally posted on 10/20/2005:

There are people out there who seem to think that merely by taking a 20% bonus on their deposit at a -110 line set book with a 5x deposit and bonus rollover, they can expect to profit in the long run simply by running through their entire rollovers as quickly as possible.

Unfortunately, however, this is not the case.

Playing at a -110 line set book, the house edge is 4.55%.

If you deposit $100 and the book pays a 20% bonus you receive an additional $20.

If the rollover is 5x the initial deposit and bonus (at some books, such as Pinnacle, the rollover only applies to the initial deposit and not to the bonus), then you need to put in play 5 x ( $100 + $20 ) = $600 before you can withdraw the bonus (and at some books, such as Cascade, also the initial deposit).

If you bet $600 at a house edge of 4.55%, then you expect to lose $27.27. Because the house paid you a $20 bonus, this means your net loss is $7.27 or 7.27% of your initial deposit.

So a 20% bonus with a 5x rollover is not a profitable situation for those attepting to purely "bonus whore". But where is the breakeven point?

The following chart shows the bonus amount in the first column and the maxmimum rollover for pure "bonus whore" profitability at -110 books. This means that if the rollover is less than the number in the second column, then pure "bonus whoring" at that book can be expected to be profitable.

Code:
Bonus	Max Rollover
5%	1.05
10%	2.00
15%	2.87
20%	3.67
25%	4.40
30%	5.08
35%	5.70
40%	6.29
45%	6.83
50%	7.33
55%	7.81
60%	8.25
65%	8.67
70%	9.06
75%	9.43
80%	9.78
85%	10.11
90%	10.42
95%	10.72
100%	11.00
Some other things to consider:
  • If you plan on wagering anyway, you may as well make a deposit at a bonus paying book. This is provided of course that you are already comfortable with its SBR rating.
  • Playing only the rollover and withdrawing at a 20%/5x -110 book is equivalent to playing at a line set of about -102.5 with no bonus. If you can be profitable at a -102.5 line set, then go ahead and play as many 20%/5x books as you can.
  • The figures above are for books offering a -110 line set. If you play at books where the house advantage is lower than 4.55%, or if you can find scalps, middles, or any other value bets with a lower house advantage, then you may have a profitable situation even for higher rollovers. As a rule, for profitability the following inequality must hold:
    Code:
                               %bonus
Expected % loss < -------------------------
                   (1 + %bonus) * rollover
    For example, if you can run through your entire rollover at a 20%/5x book with a leg of a scalp or middle with less than a 3.33% expected loss per side then you have a profitable bonus whoring opportunity.
  • The above only strictly holds for a bettor placing small bets relative to his deposit+bonus. If the player wrere to increase his bet size he'd also increase his expected value (as his probability of going broke at the bonus book would increase, thereby his increasing his probability of never having to complete his rollover).