Performance Issue

I made a Gamemode on a server where I only have access to command blocks however because I now use around 40-50 Repeating command blocks and around 30 Chain command blocks that constantly run I get a Lot of Performance trouble, however most Command blocks dont have to run all the Time they just need to run when a certain creteria is met when a certain score is reached, how can I make this so it only runs whenever needed because right now they all check all the time when if the score is met however they would only need to run when the score is met. This leaves me with a noticable lag