What do you consider feeding ...
someone who goes 13/12 or 4/7 in a 45 min game?

Won't say what happened, but saw an argument about this in one of my previous matches between a zed mid (13/12) and mf adc (4/7).

Alright so neither of those scores are feeding feeding is when you have like 0-3 kills and 8+deaths.

Zed. 12 deaths is a lot no matter how long the game is. I wouldn't be especially thrilled with my MF's performance either, though.

It's a pretty dumb question, though. The definition of feeding is giving the other team many kills. Obviously more deaths = more feed... feeding is not a ratio thing.

Feeding would be having 0 kills and 0 assists but a large amount of deaths IMO.

For me, the only criteria I hold the support to KDA ratio-wise, is if their kills and assists add up to more than their deaths.

For top lane, it's all good really since top is imbalanced but I draw the line at 0-4-0.

With this meta the most common feeders are tops and supports anyways.

Depends on a lot, for example, if I didn't know the two champions, I would say Zed, but in this case I would say MF, because while she can be in the backlines waaaaaaaaay back ulting during a fight, Zed has to straight up and fight someone, which usually results in him dying, but MF is great at kiting and staying back. If both were to play their champions well MF would have little deaths and quite a bit of kills and zed would be within 1-2 kills of his deaths for most of the game or better. This is assuming they don't go facecheck bushes or split push with the enemy team MIA or do anything generally ill advised and dumb.

Just quit league

I reserve the term "feeding" for the laning phase so it would depend on this particular game. If you have alot of deaths in the team fight stage but the rest of the team wipes them up then it was a good death. Giving the team alot of kills early makes the fed champ an absoloute monster mid game.

I'd have to agree that a large number of deaths with no assists or kills would be feeding. But circumstances has alot to do with me forming an opinion on whether someone is feeding or not. If you kept running in aggressively when your behind level and item wise, or falling for the same tricks over and over. Id definitely consider that feeding. But if a lane is constantly ganked and or tower dived by 3 + of the opposing team. I would consider that my own teams fault for not assisting when we knew it was happening.

If you can keep (kills+assists)-3*deaths > 0 (a very rough measure of your fight-related team support), I'd say you did ok and didn't feed. The greater the result, the better you did. Assists in that should probably be normalized to the team's kills/assists value and I'd rather it be -6*deaths, but it's a rough guide so take it as you will.

Point is one kill/assist for one death is never* worth it. If that is negative, you are likely being too aggressive and feeding.

* If your death gives them 15g and you get 500g for the kill, fine.. worth it. But the damage has been done.