Are you talking about 50 % on TO for 1 bet or 1 race as it has never been possible by anyone EVER in the long history of Horse betting to achieve 50% on TO over the long term.

7 - 15 % is possible if your one of the Top Flight bettors in Australia .

I leave the 50 % on TO figures to the imagination of the sharks,conmen and system sellers who abound in the industry.
Their good for a giggle though.

Cheers.