Time for P.E.
Very few students enjoy P.E. and all the activities that come with it. To be honest, it’s not so much the physical activity that kids detest but the tests and grading that they have to endure. This OP found a rather simple yet clever hack to beat the system and become a star.
Since his school would grade them based on how much they improved over the year, he would purposely perform badly on the first test. Then, in the end, he would do much better and his miraculous improvement would earn him a better grade. Now, why didn’t we think of this one?