As you give your Chao more Animals and Chaos Drives, its stats will increase. This is very important if you want your Chao to do well in the races. In the Dreamcast Game the maximum stats can go up to is 999. On the Gamecube, the maximum stats can be is 3266 (Explained more in the SA2:B Section). I will list the stats below and their attributes:
Swimming
Swimming is needed when your Chao must swim.
It is important to raise swimming or you will lose your position in the races to the better swimmers.
An extremely bad swimming stat will also mean that they won't be able to swim in the Chao Gardens!
Raise swimming by giving your Chao yellow class animals and drives.
For Dreamcast, your Chao learns to swim when its Swim stat reaches 100.
Flying
Flying can be very useful when you have to jump into a pool or fly over a ledge, because you can get ahead easily if your flying stat is high. You can raise the flying stat by giving your Chao purple class animals and drives.
Running
Running is probably the skill needed most when racing.
Nearly all races have a huge emphasis on running and if your Chao has a good running stat,
it will be at a big advantage.
Running can be improved by giving your Chao green class animals and drives.
For Dreamcast, your Chao learns to walk when its Run stat reaches 20, and speed of walk increases at 100.
Power
Power is needed mostly when climbing cliffs. Some races with cliffs also have trees at the top that also require power from your Chao to shake a nut down. You can increase your Chao's power stat by giving it red class animals and drives.
Luck
On the Dreamcast, Luck is raised by choosing the correct treasure chest in the Chao Adventure 2 mini game. On the Gamecube version, it can be raised by giving your Chao gold class animals (this is NOT true for the Dreamcast game). Luck is needed on some of the courses where at the end; your Chao must choose a lane to run down. If your Chao picks the wrong one, it will fall down a hole and probably lose its position.
Intelligence
Again, on the Dreamcast version, Intelligence can be raised in the Chao Adventure 2 mini game, this time by eating Smart Fruits collected there. The Gamecube version lets you raise intelligence by giving your Chao blue class animals (but NOT in the Dreamcast version). You should raise intelligence as it will help your Chao solve the different puzzles in the course such as the shape game, and how quickly it solves the jack in the box puzzle.
Stamina
Stamina is one of the most essential parts or racing.
If your Chao has a low amount of stamina, it will run out easily and your Chao's running speed will drop greatly.
Stamina can be raised by eating nuts from the trees.
You can also cheer for your Chao by using the trigger buttons.
This will shortly give your Chao an extra boost of speed.
However, be careful, as doing this takes away more stamina than usual so you should try to pace yourself.