Betfair Rounding of PL in markets

If it bothers you, post your bank details and I'll transfer a quid.  That ought to cover you regarding this for the rest of your life.

So you think they might be pulling the old Superman III / Office Space trick... (http://en.wikipedia.org/wiki/Salami_slicing)... but my check doesn't agree.

If we are backing
BackerStake    Odds    MyProfit    BFProfit    BF-My
2.01        2.1    2.2110000    2.21        -0.0010000
2.01        2.5    3.0150000    3.01        -0.0050000
2.01        2.58    3.1758000    3.18        0.0042000
               
If we are laying               
BackerStake    Odds    MyLiability    BFLiability    BF-My
2.01        2.1    -2.2110000    -2.21        0.0010000
2.01        2.5    -3.0150000    -3.01        0.0050000
2.01        2.58    -3.1758000    -3.18        -0.0042000

So sometimes rounded up and sometimes down... and back and lay match exactly... leaving no salami on the table

There is a little game here though:

BackStake Odds    MyProfit    BFProfit RoundedOdds    MarginalOdds
2    2.58    3.1600        3.16    1.58000   
2.01    2.58    3.1758        3.18    1.58209        3.000
2.02    2.58    3.1916        3.19    1.57921        2.000

So if you want to back at 2.58... if you bet £2 you'll get 2.58 after rounding... if you bet £2.01 you get better odds on that next penny, and if you bet £2.02 you get worse odds on that next penny.

Fascinating... I must find something more worthwhile to do now.

If you're betting in pennies, then rounding can be noticeable. It's hardly going to make or break you though.