fps drops?

My last game I had fps drops that occurred about 3-4 times in game and not sure why. I checked my task manager and nothing in the background seems to be causing the issue that would spike memory or disk and most of the time in game I sit from 100 to about 85 fps on average with the settings on the semi lower end. I adjusted the settings in game and noticed the frame rate still dropped at the defeat screen for me. Wondering if anyone else is having these issues or maybe it's just my client/pc. I can look into the next few games and or customs and see if it happens again, but I wouldn't be surprised if it was another patch related issue.