10-90

 We use the 20-80 - at work, in Kung fu, in life. The rule basically says that 20% of your input is responsible for 80% of your output. So it is a way to focus on what is important. 

The 10-90 rule is different. This is where as instructors we provide 10% of the student growth while the student is responsible for the 90%. 

The fascinating thing here is that the 10% will be bigger in the same proportion the 90% is. Meaning that the more a student is putting into their training, the more an instructor can help them.