How accurate is the GoProblems rating system?

[negapesuo]

Fun question - How accurate would you say it is?

I'm a 11k player but on GoProblems I'm around going back and forth between 13-15k. I actually think this is pretty accurate because I considered my reading to be far below where it should be, but curious to hear what other people's experience have been. Once you plateau on the rating, does it usually reflect your go ranking (or higher or lower)?

[Jhyn]

I used it a lot when I was 1-2k and I was hovering between 6d and 7d. I was taking my time on each problem. (also, it was a while ago)

[Calvin Clark]

I've found that relative changes in ability to solve go problems that are ordered in difficulty do correlate with playing results. Really well. Like, painfully well. Perhaps suspiciously well. But the absolute numbers are meaningless. No one knows what a 1d is, let alone an 11k.

[joellercoaster]

GoProblems rank: 15k
OGS rank: 5k

Make of this what you will.

[Simba]

Hilariously inaccurate. Some of the '25k' problems on there actually require me to think for a moment, and there have been problems tagged as '8k' that I got wrong.

I suspect the issue is that when you make an account, it puts you to 30k regardless of what your rank is, and this seems to reset every so often back to 30k. So the system is artificially deflating everyone's rank, and that means the problems also end up sandbagged.