Score is totally "relative"
I applied 2-3 cards each month, from Jan to May 2015. so I have 10+ CC right now
including AMEX Biz Gold, SPG, Air Miles Plat
My scores have stayed around 710 to 730, down and up, up and down
I pay off all bills after statements generate
If you had 800 and drop 15 points, that's still nothing