Grades
Your chao's grades are very important in Competitions. You can check your grades at the Doctor's office (see Chao Kindergarten.) Ask for the Medical Chart. It looks like the chart to the right.
Grades determine how much an animal/chaos drive/fruit will raise the Skill Point. The higher the grade, the more skill points can be gained once your chao increases a level. There are 6 different grades, E, D, C, B, A, and S. The easiest and most common S to get is in stamina.
There is a range of points you will get for each Skill Level. Here they are.
S | +26, +27, +28, +29, +30 A | +23, +24, +25, +26, +27 B | +20, +21, +22, +23, +24 C | +17, +18, +19, +20, +21 D | +14, +15, +16, +17, +18 E | +11, +12, +13, +14, +15
The Chao can improve their grades by geneology. If one parent was an S-rank in Flying and the other was a B-rank flying, they will automatically inherit the highest rank.