How to get an intuitive value for regression module evaluation?
To get an intuitive contrast, I came up with:

Refer to 
$$R^2=1-\frac{\sum ( y_i - \hat y_i)^2} {\sum (y_i - \bar y)^2}$$  

My method is:
$$My Value=\frac {\sum |y_i - \bar y|} {\sum | y_i - \hat y_i|} $$
Indicating how many times the model better than other model, always predicts mean value.