Anyone have any clues on how BFSP is calcuated?
I've always assumed it was similar to the tote, however have been noticing in some of the lower liquidity markets it just doesn't seem to work that way.

For example Goulburn R1, Horse 7 today.
There was $38 backing it at SP, yet $1640 on the lay side, but the start price was $12.91. What happens to the extra money that was there to lay it?

Is there some black magic going on in the background that somehow backs and lays other horses to create a balance? I'm not complaining either way, as it obviously somehow works which is great for me, more just interested in trying to understand how they match it all up when its very out of balance like in the above example.