AutoScoll

Keep the relative position of the line where the cursor is on the screen.

Setting:

Write this line to your vimrc:

let g:cursor_lines = 0.3

That means the line where the cursor is on the screen will always 30% from the bottom relative to the vim window 's height. It can also be set to 40%, 50%. (let g:cursor_lines = 0.4, let g:cursor_lines = 0.5)