Run the check
Leave the stick untouched and record the resting axis values.
Move it slowly from center and note when the game responds.
Adjust the game's dead zone one step at a time and repeat the same movement.
Read the result
Choose the smallest setting that suppresses unwanted motion in that game.
Limits and next step
Browser axis values may already include a driver dead zone.
Repeat the check after changing one setting or connection. Keep a record of what changed before deciding whether the device needs service.