Diamond ore distribution changed between 1.16.5 and 1.17

Ok, i did another test too since i was noticing the scarcity of Diamonds in the latest release (1.17).

Using a completely random seed which is: 5424481921198933946, i generated two test worlds, one of them on the 1.16.5 version and the other on the 1.17.

I positioned myself at the initial coordinates

-58 15 21

and i repeatedly used the following command:

/fill ~-15 0 ~-15 ~15 ~ ~15 air replace #minecraft:diamond_ores

until i arrived at the coordinates:

-58 15 553

These are the following results:

1. I found a total of 258 Diamonds (Diamond Ore) in the 1.16.5 version;

2. I found a total of 229 Diamonds (Diamond Ore and Deepslate Diamond Ore) in the 1.17 version.

So i can confirm the issue.

P.S. I just wanted to add that this random seed wasn't the only one i tested and compared with the previous version and all of them had less Diamond Ores on the 1.17 version.
I also noticed and this might be important that on the 1.17 version the various Diamond Ores seem to spawn more frequently lower down in the world, next to Bedrock or very close to it and generally below lava lakes (which makes them extremely frustrating to find).
The Median Altitude of patches of diamond Ores in 1.17 seems to be 7,77... i also have some photos of me running around in Spectator Mode to highlight the issue... tell me if they are needed.

Xisumavoid just released a video with similar results to JimmyReporter's analysis. They are not only less common, the actual distribution of diamond ore seems to have changed from 1.16.5 to 1.17.

The current diamond ore generation in Java edition is correct see this tweet from @unknown

That is very weird... I do not remember this change being announced. But I guess this should be closed as WAI then.

I'm gonna be a little bit polemical right here but i just wanna say that i predicted that things would stay this way.

@[Helper] Anthony Cicinelli
This modification to Ore Generation was never announced as @ampolive said nor in a tweet neither in the patch notes.
To me it seems that we gotta cope with an unintended modification in Ore distribution because the fix is too difficult to implement and all of this while not warning the userbase of such a change.

There are multiple reports of this being an issue within the userbase with many complaints on various subreddits and discord servers since as i previously explained the lava lakes makes the process of acquiring diamonds extremely frustrating.

You're just dismissing the issue and the complaints with a very brief tweet without a further explanation, it seems a very bad way of communicating from the developers in this aspect.

I guess we just gotta cope with this issue until 1.18 is implemented even though i do not agree with this decision and i'm sure i'm not the only one.

I can agree with the user above, it's kind of not good if the developers aren't communicating properly. Why was this change made? It makes new worlds more difficult.

I also agree, but this isn't the place for discussions. Maybe slicedlime thought that all the players were referring to Bedrock behavior, hence the tweet. Let this issue be resolved as WAI and eventually someone can create a thread about this on the r/Mojira subreddit.

@ampolive
Yeah you're right, maybe i shouldn't write such an essay on this problem but some more explanation coming from the devs, helpers or modders would be appreciated by anyone i think, that was the point, i hope they can reply to our concerns.

@ampolive I guess you were right, i think that slicedlime thinks that we talking about the Bedrock Edition bug as seen from this reply of his on the Java 1.17.1 Pre-Release 1 thread on reddit:

You're talking about a Bedrock-specific bug. This post is about a Java Edition pre-release.

I would still maintain the bug report open until we have further verification/clarification from staff members/devs.

This becomes a very circular argument if my tweet is used as source info that this is correct. The very reason I have been saying that there isn't a problem has been the lack of any bug report on this tracker. In fact, given the amounts of complaints going around I am amazed that there has been no substantial information about this on the bug tracker until just yesterday, while there has indeed been lots of proper information on the Bedrock issue.

So as a learning for all of you (and your favorite content creators): If you encounter a bug that you really want fixed, stop making videos and tweets and start putting info on the bug tracker. Confirming this as Community Consensus.

@[Mojang] slicedlime

Thank you for your interest on this situation!
Sorry if there has been lack of reports on this issue previously, i know for certain though that a lot of people have experienced this bug.

I provided a lot of information as requested by the mods/staff and so did @ampolive and @Zedanity too.
If you need further tests or verifications just tell us so we can test it out.

I'm unable to confirm this.

I generated the same world over a 128x128 chunk area, once in 1.16.5 and once in 1.17.

My results are:

• 1.16.5: 58,650 diamond ores

• 1.17: 60,914 diamond ores (including both regular and deepslate ores)

So, they appear to be slightly more common in fact.

Did the distribution change? Yes – diamonds now also rarely appear at level 16, they didn't before; and they are found more commonly at level 15. Apart from that it seems unchanged.

Other ores, apart from emeralds (MC-226926) still have the same distribution as before too.

Here's my spreadsheet with all the data, you can also find more graphs (also for other ores) there if you're interested: https://docs.google.com/spreadsheets/d/19xTSzZ-aIfgwfxPrVlgrskE1Iu9RmYfBrjcIUTwpJJE/edit?usp=sharing

For reproducability, the world seed is 1655054676 and the investigated area is 0 0 0 to 2047 255 2047.

Not sure if the sample size is large enough but to me it seems like it should be.

Hi everyone, I did a test too comparing the generation of diamond ores both in 1.16.5 and in 1.17 Java. 

The seed that I used is: -7297006097225229061

I did my test between initial coordinates

0 15 0

and final coordinates

0 15 750

In the 1.17 version I found a total of 344 diamond ores (deepslate included).

In the 1.16.5 version I found a total of 355 diamond ores.

Which correlates with a reduction of 3.19% in the 1.17 version.

Furthermore, it seems that the Y-level in which they are more common is lower than the 1.16.5 version. 

I used the following command: 

/fill ~-15 0 ~-15 ~15 ~ ~50 air replace #minecraft:diamond_ores

Even if the sample size is not as big as the one portrayed by the staff member above, I still suspect that at least for some users (including myself) diamonds are rarer and most importantly their distribution is skewed towards lower Y-values.

If some other users can provide the data that the youtuber Xisuma exposed in one of his recent videos I think it would be beneficial.

I am eventually at disposal for more tests. Let me know. Thank you. 

A person called Grzegorz Graczyk (Noxitu) on Twitter made a similar analysis. Here's a link to the result. The analysis was conducted on seeds between 1 and 12 using 1.17 and 1.16.5. For each seed server was started, generated initial 23x23 chunks and then stopped. In 1.16.5, there were 23344 diamond ores in 1.16.5 and 23157 diamond ores in 1.17, which seems marginally lower but it should be within a small margin of error. I don't know if I have the permission to attach the images here.

Another analysis by Twitter user Mia found slightly different results.

@ampolive

I saw the result of the test you linked... (made by Grzegorz Graczyk (Noxitu)) yes the amount of diamond ores seems within the margin of normal statistical variation since it's only a -0,8% lower in the 1.17 version.

I noticed from the images however that the Diamond Ores altitude distribution is surely changed though, i think you should really upload those images.

They seem to confirm what @Johnny_9610 was talking about... maybe there's not (at least for everyone) a total amount of diamond ores reduction but the Y levels in which they generate seems much lower; these results would also partially confim the ones brought by Xisuma in his video. Xisuma's Diamond Ores Analysis

Y layers 8 ; 7 and 5 seems to be the most productive in terms of Ore allocation which is a deviation from the standard behaviour of 1.16.5.

Also, their distribution is much more varied on various levels with an amount that goes less than 2k (1750 median if i saw correctly) on 1.17 on each level this may contribute to their perceved rarity.

I think that THIS  might be the reason behind the rarity of them, not really the total amount (maybe) but their distribution.

We need further tests but i personally cannot recreate, at least without mods, the sample used by the mod above.

We should really investigate the Ore Distribution though, that seems the key.

TL;DR Even if not the total amount the distribution has clearly been modified.

Attached the images with the results of Noxitu's analysis.

I attached an extract of Xisuma's video on Diamond Ores in 1.17 as an image to give an immediate example of his evidence, i hope he doesn't mind since it's for bug testing purposes. All credits go towards him of course.

On the left you can see 1.17 distribution on the right the previous distribution.

I recommend to watch his video that i linked in the comment above though in which he goes on a much more precise discussion about the issue.

Also, idk if it's possible but if he can reach the developers or viceversa it would be ideal i think.

In any case I think it would be beneficial to rename this ticket to more accurately reflect the issue, the ore distribution rather than the amount. I think Xisumavoid's analysis does not have a large enough sample size to adequately reflect the ore distribution in 1.17 as well as Noxitu's and violine1101's graphs.

I'd like to add my two cents to this.

First, there needs to be a distinction between what reality is, and what reality feels like. I ran some tests , and they fall in line with Xisuma's distribution, I used violine's 1655054676 seed and tested from 0,0 to 1023,1023. Not as big of an area, but should produce something hopefully conclusive.  (1.16.5 in blue, 1.17 in orange) Even with a decent sized sample, using just my data it looks like it's best to mine at Y=8 in 1.16.5, and Y=12 in 1.17, when that's not exactly the case. To me, this means that it's possible Xisuma didn't get it quite right, possibly. Without a test with hundreds of thousands of blocks instead of just thousands, there's not much certainty here.

The distribution is fine. Diamonds seem to generate more at Y=14 through Y=16. The amount is also fine. I did run a test with the 1.18 datapack, and there are almost no diamonds above Y=10, you'll have to go below 0 to find a good amount, but the generation is also nerfed on the pack. In a 9x9 chunk area (roughly 150x150), there were a total of 241 diamonds between Y=-64 and Y=-40. Scaling that up to the 1024x1024 test without the datapack, it seems that the number of diamonds distributed between -40 and -64 is roughly the same*?* as between 1 and 16 normally. It's the same amount of diamonds, but the amount is much more spread out, so it's much harder to find diamonds while strip mining with the datapack installed. Some people may have this and not be able to find diamonds, and I know that's not this specific issue but it's worth knowing the difference between the two versions. Part II is still being worked on so I'm sure this won't be final anyways. So as long as you don't have the datapack installed and enabled, ore generation should be fine.

(Y=11 Still seems like the best place to mine, since lava lakes can get in the way below this level. If anything more diamonds at 14-16 should help since lava may cover diamonds below 11 and air pockets around these lakes will expose these higher Y levels.)

With the original sample size of a 100 and 200 block radius, there's going to be some difference between versions, because ores are in fact generated differently. However, there is some randomness in the number of diamonds generated. A difference of 3% even over hundreds of samples seems explainable by chance alone. If, let's say hundreds of thousands of samples are collected, and the percentage increases even more, then it may be fair to say that there is a significant difference in diamond generation between 1.16.5 and 1.17, and there are mathematical ways to test this. Even still, violine got roughly 3.9% more ores on 1.17 in their test, which may also be chalked up to random chance. Only with more samples do we get more confident in the results, it's just a question of where do we reasonably draw the line? Distributions have standard deviations for a reason, not everything is going to be exact.

I know it may not feel right, but diamond distribution is really not all that different. I did run another test, however. I took the blocks in a 2x3 tunnel running for 5000 blocks at Y=11 in both versions of the game on the same seed. I did not write down the exact numbers, but I can tell you the number of diamonds in these tunnels ranged from 23 all the way to 72 on both versions. That's the difference between a full set of tools and a bit of armor, and a full set of tools and armor for you and someone else. Due to the high variability, you may have just gotten either lucky or unlucky. And with millions of people playing the new update and some of them inevitably getting unlucky, they take to the bug tracker and report it as a bug. If you got the 72 diamond tunnel before 1.17 and after updating got the 23 diamond tunnel, you'd obviously suspect something to have gone wrong in the ore generation. Confirmation bias is strong with this one. This is why large-scale testing is important.

Oh, and here's 1.16.5 and 1.17 diamond generation side-by-side. 1.17 is the top one, with the amethyst geode. They look roughly the same, but with a closer look I think that 1.17 generates ores in smaller veins, (maybe in this sample less frequently too), but I found singular diamond ores seemingly more often, but there's not a way that I know to test this without counting manually. I overlayed a potential strip mining path in red and blue, with one being a worst-case scenario and blue being a best-case scenario. Both of these should be equally likely to happen, so if you get blue in 1.16 and red in 1.17, I can see why one may think diamond generation was changed. (It's crazy that they're only a few blocks off!) However, due to the random nature of ore generation, you're bound to get closer to the average number of diamonds the more you mine, eventually. It's okay to get unlucky sometimes, but statistically, bad luck won't last forever. I hope some of that made sense.

TL;DR - It's all down to luck. On average the distribution seems roughly the same, with a bit more diamonds between Y=14 and Y=16 (This is all true long as you don't have the experimental 1.18 datapack on). Aside from that, it's hard to say. You may get unlucky, but just keep mining!

I think that they turned down diamond generation in 1.17?
I'm not sure

@Niko

Still the generation has been somewhat changed between versions since even @violine1101 noticed that diamonds now generate at Y:16 when previously this wasn't the case.

Also you said that:

1.17 generates ores in smaller veins / I found singular diamond ores seemingly more often

Which is another argument for the perceived rarity of the ores, so far we basically agreed on the fact the diamond count is roughly the same with some statistical variation that seems still in the margin of what you could expect.

But what i'm saying is that we need more tests and to my understanding you also think that they could be useful since the main problem seems to be the Ore Distribution... you say that it's fine while imo it isn't, it wasn't specified in any of the patch notes that for 1.17 diamonds would generate in smaller veins or with singular ores or at Y:16 so we need to know now... is this an intended change?

And this change, which seems small could have an effect on how "lucky" you need to be to find these ores, they are more sparse now that's what i'm saying and less clustered which points to the fact that they may be more difficult to find even if their total amount is basically the same.

We need more data on their altitude and on how much clustered they are before reaching conclusions imo.

Did another analysis. Seed: -6798331664095837875 (same as description of this bug report), area: 0 0 0 to 4095 255 4095.

• 1.16.5: 235,491 diamond ores total

• 1.17: 242,667 diamond ores and deepslate diamond ores total

Here's the distribution:

I think it's fair to say that the ore distribution changed, but not that diamonds did get in fact less common. However that new distribution might result in a perceived increase of diamond ore rarity. I've changed the title of this bug report and set it to confirmed.

Here's the spreadsheet for this analysis if anyone's interested: https://docs.google.com/spreadsheets/d/1jGjWQqab69PkJ91XB_lpxPFTFImyC2UaqqjGgjtUkxY/edit#gid=2132600518