You did everything the video said and nothing ate.
There’s a particular kind of bad day where you can’t even work out what went wrong. No follow, no bump, no short strike worth reading. Just a few hours of decent casting, and then a drive home spent trying to decide which of the forty things you did was the one that cost you.
Most of those forty things didn’t matter. The one that did is usually findable — but only if you start from what you actually saw, rather than from what you’ve already decided you did wrong. Those are different questions, and only one of them has an answer at the end.
So this asks what happened. Not what you think happened.
A follow isn’t a smaller version of a blank
This is the part that takes a lot of people years to notice, and it’s why the first question is the one that matters. If a fish came up behind your lure and turned away, you’ve already done two of the hardest things in fishing: you found water that was holding fish, and you got something in front of one. Nobody tells you that. The forums will hand you nine lure recommendations instead, which is a polite way of saying the problem was your shopping.
It wasn’t your shopping. It was probably one thing about how the lure moved, and you’re close enough to find it.
The same logic runs the other way. If you broke off, the fishing worked and the tackle didn’t — those are separate skills, so you can quit second-guessing where you chose to fish. If the lure fouled every cast, you didn’t learn anything about the fish at all, and reading meaning into that kind of blank is how people talk themselves out of a perfectly good piece of water.
What it won’t do
It won’t tell you the fish are biting, because nothing can. It has no weather feed, no solunar table, no confidence percentage, and it doesn’t know your lake. It reads the one thing you brought back that carries real information — what you actually saw — and it tells you straight where that stops.
That last part’s on purpose. A tool that always spits out a confident answer is just guessing for you and hiding the guess. When this one can’t separate two causes, it says so, and the coral band at the bottom is where it owns up.
Why every answer is just one change
Every candidate above ends with a single change to run next time, and they’re single on purpose. Changing lure, depth, speed and location together is how a person fishes for five years and gets no sharper — every session has an outcome and none of them has any information in it, so there’s nothing to build on.
Hold everything still and move one thing. It’s slower, and it’ll feel like you’re wasting the good light. It’s also pretty much the whole skill. The capability map is built around that idea if you want to see where it goes, and What Happened? takes each of these causes apart properly when the short version isn’t enough.