Quote fromThings that need to be said.
Confirmation/Observation bias and "Correlation doesn't imply Causation"
If you aren't a link follower:
Correlation doesn't imply causation means that just because you find things together or at the same time doesn't mean they're linked or caused by the same thing.
"I found a dollar when I stubbed my toe at the carwash change machine. If I stub my toe again, I'll find another dollar!"
Observation bias is the bias of only looking in the area you expect positive results to see if you get positive results.
"If I stub my toe, I'll find more dollars. I shall test this repeatedly once a week or so at the carwash change machine. There's no point in doing it in the woods as well."
Confirmation bias is the bias of seeing only what you expect to see, and ignoring any contradictory evidence.
"I didn't find a dollar when I stubbed my toe this week. But I did last week, and two weeks before that. And 5 months ago. And last year. That's 4 stubbings = 4 dollars, SEE?!"
Fact is, caves just have the advantage of 'pre-mining' a bunch of squares. If you go down to any of the diamond levels, get any of the modding programs and make a 5x5 tunnel in any random direction, you'll find a very similar number of diamonds in the walls. You could do it by hand too, it's just slower.
I'd rather see some math than some psy101, preconception isn't the point. Going from 5 diamonds found total after a day spent derping around the first 15 levels to 15 diamonds (20 total in 2 days) found after an hour and a half mining exclusively on layer 12 is pretty dramatic. I'd have a lot more but I wasn't 100% focused on grinding rocks, and stopped to spend some time to make a water elevator.
There were many more that I didn't screenshot because they just kept popping up one after another.
Diamond nodes aside, the greatest benefit IMO of layer 12 is how effectively you can dispose of lava threats. At this level I didn't encounter any lava above my feet. All it took was a bucket of water to keep mining, and now I have at least 100 obsidian to go back and mine someday. As Adversity said, a "sea of obsidian". The absence of intrusive lava pools will itself increase the speed and efficiency you can mine, which logically means more diamonds per minute.
There are dozens of ways to refute it, but from what I'm standing: I got a tip, I tried it out, I found an armfull of diamond almost immediately. Extremely satisfied with this simple guide, and will recommend it to anyone interested.
E: The texture pack is The Cel-Pak. Thetonestarr did a great job on it. My only gripe is that leaf textures have no transparency, which makes chopping really big trees kind of a pain. It's a quick fix, though, I'm just lazy at the moment.