I sparred almost every day I was at practice for pretty much over 5 years and EASILY see the benefit of daily sparring. Mind you these were not 10 round wars every day...it's up to the coach to guide you to improve, and sometimes it may be more beneficial to restrict you in sparring....such as have you only throw jabs for some rounds if he thinks there's something you need to work on in that department. But within those limitations, you should fucking go to the max of your lung capabilities....if it's jabs then i guess you've got more energy from not throwing the right and combos so you better double, triple, quadruple them up and throw hard... or you may have a facial injury that needs to heal immediately before a fight so the coach may have you go all body shots for like 4 rounds--go hard as you would in a fight for each round.... also it makes more sense to spar hard for 4 rounds than conserve your energy to get through 8....you've got to get used to amateur boxing's pace. You don't have 4,6, 8, or 10 three minute rounds to set up strategy and work so you better work your technique to a pinpoint and do it while sparring hard, otherwise you'll just be a dear in headlights come fight time.