Hi
The help file says on previous triggered event's
"Checks the parameters of the market that immediately precedes the current market (according to its start time), provided that the current trigger has been applied to that market. That is, the program will look for markets where the trigger has been executed before. If it finds one or more such markets, it will pick the one that starts just before the current market. If there aren't any that fall in this category, the condition will not be satisfied."
If you have separate triggers for Win and Place then it should work, but it is start time related, so could be open to error if there are delays etc.
But I would suggest setting 2 user variables in the current market when it is settled, which you could then use in the next markets:
prefix rcwin_ points explicitly to horse race win markets
prefix rcplc_ points explicitly to horse race place markets
so 1 trigger, with 2 actions, market status is settled, scope: individually for each event, to write the following values to user variables:
rcwin_market_settled_pl
rcplc_market_settled_pl
then you will have Win and Place profit/loss separately for each event which you can use.
Hope this helps.