I created a scoreboard using the stat.damageDealt. When testing I noticed that when hitting a mob with an arrow the scoreboard would not be updated. It worked fine when hitting any mob with a fist but never updated when hitting a mob with an arrow. Not entirely sure this is a bug but assume it would make sense since the arrow counts as being damage dealt by the player. The pictures show the exact process I used to set up the scoreboard. As well as it working when punching a mob but not working when firing multiple arrows into a mob. Thanks for your help.
note: tested in 1.7.9, and 14w21b