Type of bets

Can someone please explain to me what a cross double bet is
Double bet is you choose horse in race 1 & 1 horse in race 2.
Both horses must be placed first for you to win.

When i was a lad it was a popular bet but most bookies stopped taking them..

example of a crossed double..

A cross double as i understand is you give the bookmaker instructions R200 on a 15/10(selction a) shot and you ask for say %50 to be crossed on to selection b..

so you have R200 onto a 15/10 shot x 50% onto selection b @ 1/1 and they both win returns would be as below..

R200 @ 15/10 =R500

50% @ 1/1 = R500

R250 Returned to account(excess) + R500 for Returns from Selection b

Total Returns

R750

Thanks hibernia,

That explains why I didn't come up with anything when I tried to google it.