i dunno where ur from, but in Australia most ppl take trifectas in bigger races, because the more money in the pool gives better results, and u cant just back say the first few favourites, thats why u get bad dividends of $17.50, u hope to include a few roughies and hope they win or place,
i remember 1 year in the MELBOURNE CUP, my sister had $10 to spend, she had $1 on a trifecta and $9 on quinellas, picked up $1600, picked a fave and 2 roughies in the tri, and boxed them all in a quinella,
mate once again not sure where ur from or anything about u, but horses is VERY VERY hard to make money out of, ive worked with trainers and managed jockeys, if ur gonna have a big bet, make sure u ask the trainer, owners, and jockeys on how the horse will go, if u dont no any of them, probably save ur money, as those 3 connections 99% of the time no how the horse will run,
good luck with it
