When you make mistakes...

[Lucifer]

I don't worry about blame. I credit my opponent when it's clear and obvious he got me (which is most of the time). I only blame lag when the lag itself is excessive. If it's within my normal ping range, or if it's even a medium spike, I don't blame lag, because those are just the conditions under which normal play happens and I think that players have to account for it in their play. Failure to do so is a personal failure, and blame goes to me for it.

In the situations where there was a cycle nearby, but he didn't do it (even if the game gave him credit), I split between me making a moving mistake (a twitched finger, or mis-timing a turn) or me making a navigational mistake (I didn't know that wall was there, or I got lost in a maze, or something like that).

I blame teammates when they teamkilled me.

[INW]

If you have Airman on your team it is ALWAYS his fault. Same with Taz.

He just played teemo and we won. Sad thing is, he had 4 minion kills in 38 minutes...

I don't believe you.

Ask mecca

[Titanoboa]

When you die on Tron, do you play the blame game? How often do you hold yourself accountable for your death? How often do you hold yourself accountable for the team's loss?

It's easy to get lost in the "blame game", as it's quite addictive. You're right that it can motivate yourself, if you have a personality where failure only motivates you to become better. I'm one of those and I tend to blame myself even when it isn't my fault. It helps me improve, but it certainly annoys others if I talk about it.
I would never recommend blaming someone else to try and motivate them though, instead you should do your best to build up their confidence and encourage them to strive towards improvement.

This thread made me realize that the times when I haven't been busy finding something(or someone) to blame, is when I've had the most fun playing the game.
Lucifer brought light upon this in the post above. (no pun intended btw )

If you don't partake in the blame game, and point out solutions instead of problems should they arise, the game will be more fun. Especially for yourself, but others as well.

[apparition]

When I make mistakes, I say one of the following: lol, balls, ballsack, poop, pewp, fart, farts boobies buttcracks,
shit, ****, asdlkfj;wefjowjc;asd, <<< Defense down!

When I lag, I say "lame"

When I get pwnt, I say "wd" or "wow", usually "wd [player]"

[AI-team]

When I make mistakes, I say one of the following:(...)
asdlkfj;wefjowjc;asd,(...)

Do you have an instant chat?