When to resign

[Bonobo]

After you lose 5 stones in the fuseki due to a dumb mistake.

I’ve won games after losing a lot more stones in the beginning <shrug>

[Elom]

In every pro game with a difference of more than five points (except HayaGo), both players knew who was winning.

[Polama]

Personally, I like to count the board as if I'm going to get any double sente/my sente/double gote exchanges. I assume the opponent will play defensively in any exchange that needs deep reading. That's my approximation of "my opponent plays a terrible, blunder filled endgame." If that's still not enough, I resign.

[xed_over]

After you lose 5 stones in the fuseki due to a dumb mistake.

I’ve won games after losing a lot more stones in the beginning <shrug>

I seem to recall that Bill once posted a pro game where one of the players lost a 36 stone group fairly early in the game, yet still won. (I don't know how to search for and find such games)

[EdLee]

a pro game where one of the players lost a 36 stone group
fairly early in the game, yet still won.

This depends very heavily on the exact circumstances:
if the 36-stone loss was a pure loss, with little or no compensation,
then at pro level it's practically impossible
to turn the game around (barring extremely exceptional cases,
such as acute health conditions, etc.)
But if there was some compensation, even if it was an uneven trade,
or if the whole board evaluation was still very unclear,
then maybe a turn around was possible — yes, would be
nice to see the actual SGF.

[Dusk Eagle]

I've lost huge groups in the fuseki but kept playing and came back and won. That is way too early to resign.

[oca]

Did you see Hikaru No Go episode 64 "Keicho Flower Bowls" ?
It's one of my favorite... of course that's fiction but I liked that the opponenent resigned
and then they exchange side and Saï can still won the resigned game.

[snorri]

Did you see Hikaru No Go episode 64 "Keicho Flower Bowls" ?
It's one of my favorite... of course that's fiction but I liked that the opponenent resigned
and then they exchange side and Saï can still won the resigned game.

I'll have to check that out, but that's one idea to use if you are the type to resign too early. Imagine the won games you have lost and the kinds of mistakes that can happen to you. If you are ready to resign, it also means you can confident of winning against any of your normal opponents if the tables are turned. Maybe you don't have to take it to the extreme and say "okay, I'd even beat Cho Chikun if we switched sides" because then maybe you'd never resign.

You can always ask a teacher later if you keep the game records. I remember many games I gave to my teacher and as we went through them I said, "and it looks terrible, so I just resigned here." Usually he would say, "yeah, that's the best thing" or "about time!" But once in a while he would say: "Hmm. Let's see how far you are behind..." He would then play out the endgame quickly and count. I would still be ahead. Now he was playing both sides by himself very, very fast and I wasn't strong enough to see whether he was messing with my head and favoring one side, but he definitely made his point, which is that if I felt bad, I should take a breath and count the score dispassionately before doing anything rash. It's all okay. I learned go from the games I resigned correctly. I learned about myself from the games I resigned too soon.