hi
your question was
At the moment I have it set to bet on the FAV in the place market when the 6 fav odds in the WIN market are below 20, but not all races have 10 or more runners.
but not all races have 10 or more runners.
the answer is in the other post
for 6 fav odds below 20 in the win market you need to add
and selections trigger expression winplace_r_6_back_price is equal or less than 20
both conditions to be put in the place market trigger and both markets need to be monitored.
mcbee