ここで言っているドロップ率というのは0%かそうではないかが最も大事なので、 Skycrawler13さんが仰っているように出るか出ないかがわかるのであれば細かいドロップ率の表記まではなくても大丈夫です。
もちろん運営サイドさえよければ細かいドロップ率があった方が喜ばしいです。
最低限、0%なのか可能性は0ではないのか、いちいち言葉遊びみたいなやりとりをする必要がないようにしっかりと明記して頂きたいです。
提案/Suggestion
Currently, the only resources for players to know which part breaks can lead to which reward drops are external websites. There is no information in the Hunter’s Notes, or anywhere else in the game that shows what rewards you can or can’t get from breaking a specific part on a monster.
My suggestion to include this information in Hunter’s Notes for each monster, or have the rewards screen show which part break resulted in which bonus drops.
People do not understand which parts to prioritize because they do not know where their rewards are coming from.
There’s a similar topic: モンスターガイドでどの部位破壊でどの素材がドロップする可能性があるか明記して欲しい/Suggestion for Monster Guide: Reveal the Body Part(s) that drop a particular material when that material is acquired from Broken Part Rewards
熱心なプレイヤーが作成したMHNツールのウェブサイトがあります。
ウェブページの右上で各国の言語を選択できます。
The problem is that not everyone knows about these external tools, and there have been occasions where the datamined data is not the same as official data, so it is not 100% accurate all the time.
Having the information exist in the game will help everyone who plays the game without depending on them knowing external information (they will definitely play the game, but it’s not guaranteed that they will see the third-party websites).
Yeah if these numbers exist it would be great to have them displayed somewhere in the hunter guide.
As for me I’m in the team who believe there’s no such number or that all parts can drop but with a different rate.
For example I remember when Mizutsune was just released everyone believed you had to cut the tail to drop rare 6 to the point that people left before the end if it wasn’t going to happen. I used to play with Zinogre lightbowgun and now Rajang Heavy bowgun so I never ever cut the tail solo and still drop many rare 6.
Got the long sword 10.5 and 47 Mizu rare 6 to spare and the large majority of them are from solo hunt. So without an official statement I don’t know what to think about this really.
Btw I was convinced I read somewhere the reward on body parts is random but I wasn’t sure if I read this on an official website or just on Reddit comments.
Here I found the source :
So it was official from Niantic support.
The basic rewards are completely random, based on the number of monsters you defeat, which is what you get.
The items dropped by the destruction of parts should not be random. At least the items I have dropped so far are consistent with those on the MHN tool website. I only play with dual-blades, and I can only break the head and tail of the Legiana. I have never seen R6 materials given by destroying the head and tail.
I added the source in my editing ^^
And I already got Mizutsune rare 6 in the broken part reward while only destroying the head and back.
I confirmed it through actual combat. I already knew that the official description will not tell you what will be dropped. This has always been the case with Monster Hunter games, except for the Monster Hunter Rise and Sunbreak series, which clearly tell what materials will be given by destroying certain parts.
I hear you and Stampeder have such experience. I’m not being argumentative. I just don’t have the same experience as you guys. Which is why I’m not sure what to think but either way it should be addressed by officials to clarify.
それが本当なら動画でシェアして下さい。
6万以上モンスターを討伐してますがそんな事は１度もありません。
It may be faster to wait for an official statement. I don’t care who’s right or wrong but I’ll happily aim those parts that supposedly don’t give reward and share it for science.
公式の発表を待つよりあなたの証拠を提示していただいた方が早いと思うのです。
誰が間違っているとか正しいとかは関係ありません。事実が知りたいだけです。
That’s precisely what I said.
And I will contribute regardless of the result by submitting clips somewhere. If it shows that it doesn’t drop the materials so be it 
Indeed that’s officially what Niantic claimed but I don’t think the individuals who wrote that Q&A knew what they were talking about. Or maybe it’s too outdated.
Do you have a clip or something?
Unfortunately I only have screenshots of results but that doesn’t prove we didn’t cut the tail.
It was a year ago during September. I remember walking with a coworker hunting for Mizutsune specifically to get our first 10.5 and the breaking part topic came up. After a few hunts it appeared we got rarity 6 under broken parts category and agreed that there was no such thing. From this point I carried the idea until now.
But it could’ve been because of the Mizu event/version of the game back then, a tail cut accidentally by the special (he’s a bow user) and we didn’t see it or any other reason. Anyway I was just sharing my story, and although I believe it’s better if an official could just show up and give details I’m ok to share my hunts.
So far I’ve been farming Barioth without cutting the tail, gathered about 20 clips and it seems to join what Stampeder, DeathBleath, Ten8994 and others are saying. No rarity 6 under broken parts other than the one for customization so far. 
Chances of obtaining rare 6 from breaking a certain part is lower rate than basic rewards.
It will never be a significant resources of 6* mats, yet not fully ignorable.
I believe that random 5th basic reward box might have 20% drop rate for 6* even outside of the half anniversary event.
Also the group hunt reward has secondary highest spit out rate and which is close to 10% rate.
It seems like basic rewards have at least of 6-8%chance per box and it depending on difficulty of monsters.
If you are at the end gamer, you’ve been notice that sacred stones’ drop rate is ridiculously high just because only 9* and above monsters drop this stones.
Breaking part rewards might have 5% and below regardless of difficulty of monsters.
Elder dragons might have different rate though.
This rate might let you make 1 10-5 weapon out of 200 8* above monsters instead of killing 250 of those.
If you killing 500, 1000, or more and doubling rewards by using a carving knifes for 6* then it doesn’t and shouldn’t be matter to you.
It really depending on your game style and how much time you can invest in this game.
I choose to chop off tails just because I wouldn’t wondering around to look for 50 more.
Sorry, but this topic is not about drop rate but about what can drop from which body part as broken part reward and present it in the game and not depend on external sources.
Please don’t deviate into drop rate. That one is quantified and done and doesn’t really need delving into anymore.
Due to network conditions and how the game works, it is possible to miss seeing a broken body part if you happen to not be at the angle to see it and two body parts were broken at the same time. And, as long as there’s no screenshot/video recording, and given that human perception and memory are imperfect, it’s just word vs word without evidence. I’ve seen all these strange happenings myself while recording evidence, so I decided that it’s simply easier to just brute force with quantity in data and let the numbers speak for themselves and quell the imperfections in real life.
For Mizu, the tail has the chance to drop R6. No other parts. If you broke the head and the tail and you see the R6 is in the second slot in the broken part rewards, it can only be the tail because the “Head” slot is always the first, followed by “Tail”.
The problem right now is that players cannot know which part can drop what unless they look outside the game, which is not helpful because not everyone would look outside the game. Some players simply refuse to use external tools because of advertisements that cannot be blocked if they want to use the site.
Please focus on this, not the drop rate.
Yeah you’re right, sorry for deviating.