We want to make this very clear. We do not want people using substitution for every little thing. Otherwise fights become long repetitive and annoying. We also dont want people getting dependant on them with cooldown times. The numbers are how many times a certain rank can use substitution in a single fight. It will still drain one chakra point as before.
Genin: Limits 3 times per battle
Chuunin: Limits 4 times per battle
Jounin: Limits 7 times per battle
Anbu: Limits 8 times per battle
Sannin: Limits 10 times per battle
Kage: Limits 12 times per battle