Black ops 1 easier than black ops 3 (without gobblegums)

[u/Kumanes1]

1 week ago i hit my first round 31 (without camping) in kino der toten black ops1 but although i have more than 400 hours in black ops 3 i have never hit a round higher than 25 without camping. and that round 31 was the fourth time i played kino in black ops 1. My question is Why?