His is based on reality. Pavelec is a bad goalie. The teams defence doesn't change that. It just changes the amount of goals he lets in. It's pretty straightforward.
Ding-ding-ding! Winner.
Better goalie / lower SV% == lower GAA with same SA. Better D / lower SA with same goalie / SV% == lower GAA. It's pretty simple. Both help.
PS to all: there's a great Pavs discussion going on here http://hfboards.mandatory.com/showthread.php?t=1581435