GameCube pad

Analog stick range
It's important to distinguish between the theoretical and physical maximum of the analog input. The theoretical analog range is 0-128 for both the main stick and the C-stick. However the physical maximum for the official GameCube pad is only 100 (i.e. 80% of the theoretical maximum) for the main-stick and 76 (60%) for the C-stick. The official GameCube pad also has a deadzone of 0-15%, so the smallest value it will send is 20 of 128.

In addition to this many games have an even smaller maximum at which the practical maximum effect occurs, for example the level where the character runs at full speed or the camera moves at its fastest speed. On an emulator it's therefore a good idea to transform the range to a value that is closer to the GameCube pad range.