I have been reading multiple tutorials on lift and gain charts here,here,here and here.
While I understand how the curve is drawn based on our model, but I don't know how the dotted black lines for random model or dotted blue lines for best model is drawn.
I used the Python kds library to draw this line (as I do not know how to plot this manually)
For ex:
Can any of you help me with a toy data to explain why the lines are plotted the way it is from random and best/wizard model?