Recently, I realized a funny incident.
The incident was happened for two days.

Day 1 (June 28, 2017)

In this day afternoon, I realized 3 out of 7 my blogs was downvoted, though there is no blog in recent actions. It is sad, but some of this is so funny: The number of downvotes in all 3 blog was "-10".

1: A mystery of CF rating distribution (Link)


2: A mystery of CF contribution distribution (Link)


3: A mystery of correlation between rating and contribution (Link)


All of these are -10 votes differ! Why!?!?!?

The second story in this day is at night, which is a bit happy.
There is much upvote in a comment, though there is no recent action! (In addition, the differ is "+10".)

(Also, I felt suspicious about this because I think tomorrow maybe happen an incident about "10".)

Day 2 (June 29, 2017)

As I expected, an incident happened in day 2 afternoon.
There is some downvotes in other blog, which is 2 months ago and of course there isn't the blog in recent actions.

4: Square869120Contest #4 Editorial (A-D) (Link)

OH! SOMETHING HAPPENS! I expected -10 votes as previous three so the blog post rating is going to +19 -> +9, but this is +10. Interesting. (Note: All of -9 downvotes happened in 5 hours.)

=============== AFTER 4 HOURS ===============

Finally, the blog's rating decrase by 1. As I expected, the number of downvote was "10".

Summary

The incident is so mysterious and funny. A mystery about the elected number: "10".

In one sentence conclusion: "+10, -10, everywhere!".

Thank you for reading.

UPD: Thank you for gongy to react my funny story and write a blog. (Link) Thank you very much.

Update (Day 3)

Finally, the blog rating was temporary +16, but this was -50 at the end of Day 3.
In addition, the blog's rating change is really interesting as follows:

Time elpased	Upvotes / Downvotes
0 min	0
15 mins	+7
18 mins	-3
60 mins	+16
8 hours	0
9 hours	+2
14 hours	-19
18 hours	-7
24 hours	-30
36 hours	-50

I hoped that the incident won't got worse, but it was worse very much. The number of downvotes in the incident was:

Funny story	Myst. Vol 4 (deleted)	Myst. Vol 3 (deleted)	Myst. Vol 2	Myst. Vol 1	s8pc editorial	Total
-60 (0 -> -60)	-47 (+25 -> -22)	-25 (+50 -> +25)	-51 (+114 -> +63)	-25 (+154 -> +129)	-10 (+19 -> +9)	-218

The next episode (July 22th)

The incident seems to be end, but this happened again. At 7/22 20:00 JST, suddenly, most of my blog downvoted! I thought why this reason is, so I decided to update this blog.

Tutorial	Funny story	Myst. Vol 2	Myst. Vol 1	Total
-20 (+180 -> +160)	-15 (-60 -> -75)	-20 (+63 -> +43)	-20 (+129 -> +109)	-75 (Total -293)

Funny Story with "20"!?
I think this incident is so serious, and I never heard a bigger downvote incident than it in CodeForces. I really want who made 10 fake account and downvoted me. Making fake account is also an immoral thing, so please comment this blog if you make 10 fake account.

By the way, thank you for reading!