With a java script ; this is what I see when I look at the boxscore :
(http://imgur.com/a/SFDRA)
It takes into account all the attacks from both teams, their successfullness based on the opposition's defensive ratings, and spits out a "theoretical result". The ratio with the actual result is calculated to see if your team "overperformed" (understand : was lucky) or underperformed.
I've been using it since quite some time and it provides useful, though limited, data. Also it doesn't work too well with teams like Buston, whose players with a very high SB aren't well translated into defensive ratings.
Intresting stuff, did you write it yourself?
So it seems like the odds where not at my side that game...