Use 'to the good' when the result is better than expected or gives an advantage. Despite the difficulties, we finished the project two days to the good.
Pro Tip 2/3
Sports Scoring
In sports, 'to the good' often refers to a lead in points or goals. The team is five goals to the good at the halftime break.
Pro Tip 3/3
Not Physical
The phrase doesn't usually describe physical objects, but abstract advantages. He's several recommendations to the good for his university application.