I'd like to start giving people the option of commenting on shorter Cold Takes pieces (which I don't cross-post here or provide audio for). I'm going to use this post for that: I will generally leave a comment for each piece, and people can leave their comments as replies to that.
Yes, you're quite right, thanks. I failed to differentiate between my independent impression and my all-things-considered view when thinking about and writing the above. Thinking about it now, I realize ~5% is basically my independent impression, not my all-things-considered view. My all-things-considered view is more like ~20% Zvi wins--and if you told me yours was 40% then I'd update to ~35%, though I'd guess yours is more like ~25%. I meta-updated upwards based on knowing Zvi's view and the fact that Holden updated upwards on Zvi to 50%. (And even if I didn't know their views, my initial naive all-things-considered forecasts would very rarely be as far from 50% as 5% is unless there's a clear base rate that is that extreme.).
That said, I haven't read much of what Zvi has written in general and the one thing I do remember reading of his on Covid (his 12/24/20 Covid post) I strongly disagreed with at the time (and it turns out he was indeed overconfident). I recognize that this probably makes me biased against Zvi's judgment, leading me to want to meta-update on his view less than I probably should (since I hear a lot of people think he has good judgment and there probably are a lot of other predictions he's made which were good that I'm just not aware of), but at the same I really don't personally have good evidence of his forecasting track record in the way that I do of e.g. your record, so I'm much less inclined to meta-update a lot on him than I would e.g. on you.
Additionally, I did think of a plausible error theory earlier after writing the 5% forecast (specifically: a plausible story for how Zvi could have accepted such a bet at terrible odds). (I said this out loud to someone at the time rather than type it:) My thought was that Zvi's view in the conceptual disagreement they were betting on seems much more plausible to me than Zvi's position in the bet operationalization. That is, there are many scenarios that would make it look like Zvi was basically right that might technically cache out as a Holden win according to the exact betting terms described here. For example, there might be a huge Omicron wave--the largest Covid wave yet--and cases might drop quickly afterwards and it might be the last wave of the pandemic, and yet despite all of that, perhaps only 50% of the cases after January 1, 2022 happen before the end of February rather than the 75% necessary for Zvi to win.
Holden proposed a bet and apparently they went back and forth a few emails on the bet operationalization before agreeing. My hypothesis then is that Zvi was anchored on his 70% confidence from this statement and didn't take the time to properly re-evaluate his forecast for the specific bet operationalization they ultimately agreed to. I can easily see him only spending a small amount of time thinking about the bet operationalization and agreeing to it without realizing that it's very different than the concept he was originally assigning 70% to due to wanting to agree to a bet on principle and not wanting to go back and forth a few more times by email.
Of course this is just a story and perhaps he did give consider the bet operationalization carefully. But I think even smart people with good judgment can easily make mistakes like this. If Zvi read my comment and responded, "Your hypothesis is wrong; I thought carefully about the bet operationalization and I'm confident I made a good bet" I'd meta-update on him a lot more--maybe up to 50% like Holden did. But I don't know enough about Zvi to know whether the mere fact that he agreed to a public bet with Holden is strong evidence that he thought about the exact terms carefully and wasn't biased by his strong belief in his original 70% statement.
(Noting to myself publicly that I want to learn to be more concise with my thoughts. This comment was too long.)