It takes far more games to get banned for inting than I expected.
A couple weeks ago, I encountered someone who was tanking their MMR. At first I didn't realize it was intentional, because he was just making really bad ganks as a jungler and dying almost every time, but then a teammate said to check his op.gg to see that he was intentionally feeding - and sure enough, he had a 0% win rate in ranked and had a similar super-negative score in every match.
So, I donned my deerstalker cap and grabbed my pipe and trenchcoat, and I started watching his op.gg.
They were either banned or gave up on it this past week, as they haven't played a game in 5 days. Final ranked score: 2-25.
I also found that they have a friend doing this too - they played about a dozen games together, and this second player is still playing. Current ranked score: 3-39 (they played and lost another game after I took this screenshot). I assume they're using a similar strategy of extremely poor play without blatantly obvious inting (so no running down mid or troll builds) while also talking very little in chat and overall being polite.
The other thing that really concerns me though is that the first guy went 0-10 in his placement matches and was placed in silver 1. I'm in Gold V and his 10th placement match was the one he played with me, which is when I started watching his progress. His friend was also similarly placed high, as they're currently in silver 5 at 0 LP with a 7% win rate. I don't know what the initial ranked MMR is for an account, but it feels to me like someone going 0-10 in placements and getting placed high silver doesn't really make sense. But, maybe there's some other mechanics in play there that I don't know about.
Now, I know that there's always the old "Riot bans you instantly for bad words but takes forever to ban int feeders" thing, but that argument is a false equivalency - it's far easier (and more automated) to ban for chat logs than it is to ban for play. However, this is still much longer than I expected for someone to get punished for inting in literally every single ranked game, especially since a second player has been doing it for even longer and is still playing as of a few minutes ago.
Your thoughts?