Ha. Lol. I dumped the chalk and used the 2, 3 im my p5s.Didnt help. My logic for these type of races is to usually go other than the chalk, figuring even if i get beat 2/3 of the time its still a sound play longterm. 6 horse wasnt on my radar though.
Even if you single chalk and hit, the 1/5 or 1/9 adds almost no value to p5. Only exception i might make is if there is bomb that im absolutely in love with in later 4 legs. There i might single chalk and bomb and spread in other three legs.