I have noticed that after about 14 catches in a single day, when I try to catch a new Pokemon, It runs away. Has this happened to someone else?
If it runs away on your first pokeball that you manage to hit , and it happens 2 or more times in a row, it is likely that you have been softbanned for either a)playing on the highway (I was going ~80 mph with a friend who was driving, and got softbanned for 10 min) or b) GPS spoofing. You can tell if you are softbanned if you spin a pokestop and nothing drops while it stays blue, and it doesn't display the "Try again later" text. to get rid of a softban, just do this ->If its inconsistent, the pokemon might just be higher CP or rarity, resulting in higher escape and run rates.