To prevent warping purposes. U can try whatever speed you're comfortable with but results of the sliders will be different. As long as u enjoy it is all that matters. If u change game speed I recommend changing the threshold with it, slow will also give u nice animations, I've been testing Fast game speed with threshold at 62 and it's playing nice just want to continue testing, I feel like slow best resembles real NFL games but whatever u like bro. I've went back and forth between slow and fast in previous updates. I will continue testing and maybe make some changes but use what's fun to u.