Rating points dropped from 169 to 122 after liking photo - Forums

Hi everyone.

Just yesterday I had about 169 rating points, but today (after liking another photo) I only saw 122.02...
And i was thrown back to 1354th place from ~820-830 place in the overall rating…

@Salvatore Iovene Could you please tell me what this is all about?
Thanks in advance.

Hello Andrey,

Please see the attached screenshot of an email I sent a few months ago regarding the change you observed.

If you have any questions or something is not clear, please let me know.

Kind regards,

Salvatore

📷 Screenshot 2026-01-02 at 22.58.08.jpg

Hello, Salvatore.
Everything would be fine, but my rating was higher before adding just ONE SINGLE photo with the collaboration, and that's what surprised me...

Hi Andrey,

the image where you are a collaborator is from 2 months ago, but the change of calculations started taking effects a few days ago. That image has a lot of likes and and many collaborators, so it would have a significant impact on your Index.

Kind regards,

Salvatore

Hi, Salvatore,
This is exactly what I am writing about, that my rating was higher than today long before adding this photo.

I'm not sure I understand. In the top post you said “yesterday I had about 169 rating points, but today […] I only saw 122.02” - the explanation is that the calculation for the Index just changed. Up until a few days ago your Index calculation was inflated due to the fact that all collaborators to an image got the full benefits, and this just changed so the gains are shared, and this change retroactively applied to past images too.

What I meant was that my rating was above 122 even before I was tagged as a collaborator in that photo (let's say it was 130, for example; I don't remember the exact number, but it was above 122). The photo was published on October 30, 2025, but I'm talking about a time before that.

The Index can go down (regardless of these change that pertains collaborations) for other reasons. Please see the FAQ section here: https://welcome.astrobin.com/features/image-index

Thanks!

Inflation is a strange beast, even more so in AB!

Salvatore Iovene · Jan 3, 2026, 03:17 PM
…
📷 Screenshot 2026-01-02 at 22.58.08.jpg

Hey Salvatore, Thanks for posting this screenshot. I have not yet participated in any collaborations, so I did not receive this email or know this change was going to take place. (But I did know you have had many discussions in the past about the image index and have indicated changes would be coming regarding ‘collaboration likes’.)

As explained in your email above, my image index did not have any unusual changes (since I have not participated yet in any collaborations), but I did notice some significant changes to the “Astrophotographers list”. This explains it - Thanks for the post.

I don’t pay much attention to the “list” or imager ratings but this thread piqued my interest so, I took a quick look at it. Here’s what I see:

📷 image.pngIt seems really curious that out of the top-ten, five users have ZERO IOTD awards and very few other awards. Number four on the list has won just two top picks, has 1764 followers and he has made only16 posts. I’m not trying to pick on anyone but if this list is supposed to be somehow ranking the top imagers, either the algorithm assigning the ratings isn’t looking at the right things or someone somewhere is somehow gaming the system. As it stands, this list seems pretty meaningless—other than perhaps to provide a quick summary of imager stats. But maybe I don't understand it. What is the ranking supposed to be showing?

John

And here I thought this was not a competition 😀

John Hayes · Jan 5, 2026, 04:17 AM
I don’t pay much attention to the “list” or imager ratings but this thread piqued my interest so, I took a quick look at it. Here’s what I see:
📷 image.pngIt seems really curious that out of the top-ten, five users have ZERO IOTD awards and very few other awards. Number four on the list has won just two top picks, has 1764 followers and he has made only16 posts. I’m not trying to pick on anyone but if this list is supposed to be somehow ranking the top imagers, either the algorithm assigning the ratings isn’t looking at the right things or someone somewhere is somehow gaming the system. As it stands, this list seems pretty meaningless—other than perhaps to provide a quick summary of imager stats. But maybe I don't understand it. What is the ranking supposed to be showing?
John

Think of the AB index as an h-index, and this table as one of many rankings for scholars. As in academia, it's a single metric with the usual drawbacks and doesn't reflect an astrophotographer's entire body of work or successes.

John HayesAs it stands, this list seems pretty meaningless

Exactly my thoughts - likes are merely a popularity contest, IOTD's are a measure of skill.

I've attached a more meaningful list.

Andy 01:
likes are merely a popularity contest, IOTD's are a measure of skill

IOTDs are a badge of popularity with the judges, me think.

John Hayes · Jan 5, 2026, 04:17 AM
It seems really curious that out of the top-ten, five users have ZERO IOTD awards and very few other awards. Number four on the list has won just two top picks, has 1764 followers and he has made only16 posts.

It’s based on likes on your photos, IOTD doesn’t have anything to do with it. They have a ton of followers and their followers like their images. It’s really that simple.

Quinn Groessl:
It’s based on likes on your photos, IOTD doesn’t have anything to do with it. They have a ton of followers and their followers like their images. It’s really that simple.

*Not that simple. It is based on the likes intensity, that is likes per image (otherwise I'd be in the first 100 and I'm not by any stretch) and it also based on the gradient of this quantity ("likes intensity") so you need to keep a positive or at least non-null value of the gradient or your index drops.

I don’t really see the point of having the index system at all, or perhaps I’m just not understanding what it really does. What is there to gain from having a high index based on likes? It’s basically just about how much you are willing to promote yourself and people are probably farming the system in some way.

I have been reached out to by IOTD staff who, after following me and liking a bunch of my images, asked me to follow them and like their images in return. When I’ve not responded I have been unfollowed, twice. This person is a high ranking member on that list but I won’t say more in public as I have no interest in starting some sort of feud.

While this probably isn’t against any rules it still doesn’t sit quite right with me, at least not from staff.

andrea tasselli:
Andy 01:
likes are merely a popularity contest, IOTD's are a measure of skill

IOTDs are a badge of popularity with the judges, me think.

Interesting comment, but there's only one judge in the top ten list that I posted.

Andy 01:
John HayesAs it stands, this list seems pretty meaningless

Exactly my thoughts - likes are merely a popularity contest, IOTD's are a measure of skill.
I've attached a more meaningful list.

I believe that policy of Astrobin is that IOTD is not a contest. IOTDs are not just a measure of skill - they are an also measure of access to funding needed to install and operate expensive equipment in locations with great seeing, for example. Many people with IOTDs have hundreds of thousands invested in equipment at remote sites - which tilts the balance heavily in their favor. While there is nothing inherently wrong with how someone chooses to spend their money, statements to the effect that IOTDs are a measure of skill make the assumption that the IOTD is a fair contest. The IOTD is not a contest and if it were viewed as one, it would be highly unfair. if the goal is to measure skill, there would need to be radical changes to the IOTD. It disappointing that it is now being positioned as this - because it really sends a message that this hobby is for those with money.

Jan Erik Vallestad:
I don’t really see the point of having the index system at all, or perhaps I’m just not understanding what it really does. What is there to gain from having a high index based on likes? It’s basically just about how much you are willing to promote yourself and people are probably farming the system in some way.

I have been reached out to by IOTD staff who, after following me and liking a bunch of my images, asked me to follow them and like their images in return. When I’ve not responded I have been unfollowed, twice. This person is a high ranking member on that list but I won’t say more in public as I have no interest in starting some sort of feud.

While this probably isn’t against any rules it still doesn’t sit quite right with me, at least not from staff.

Thank you for posting this. An experiment I would like to do is no make my images public to my followers until they are through the IOTD process and see to what extent that changes the result over some portion of time.

Jan Erik Vallestad · Jan 5, 2026, 11:31 AM
I don’t really see the point of having the index system at all, or perhaps I’m just not understanding what it really does.

The FAQ says it was made to prevent people from making fake accounts to like their own images. Realistically I guess most people if they use it, they use it to compare themselves in the list of users. I guess I’m too far down the list to really care.

Quinn Groessl · Jan 5, 2026, 01:23 PM
Jan Erik Vallestad · Jan 5, 2026, 11:31 AM
I don’t really see the point of having the index system at all, or perhaps I’m just not understanding what it really does.
The FAQ says it was made to prevent people from making fake accounts to like their own images. Realistically I guess most people if they use it, they use it to compare themselves in the list of users. I guess I’m too far down the list to really care.

I see that now. It also states that its “evolved into a sought-after indication of one’s abilities in astrophotography” which isn’t necesssary true at all. Wouldn’t it only take a few posts and a few likes to increase the index above 1.00, to be able to give likes? The index makes it more tedious, sure, but if this is the case it’s only a speed bump and it wouldn’t take long to get a decent amount of accounts doing so as you could sustain it by yourself after a few. Just to be clear I’m not accusing anyone here, just trying to understand the index.

I still don’t quite see the point of it as it seems more like a made up popularity scale with no substance other than providing those who promote themselves the most with bragging rights. Then again, not that I know, but I’m probably too low on the list to actually care myself as well. Or maybe I’m just turning into a grumpy old man as I close in on my mid-thirties.

John Hayes · Jan 5, 2026, 04:17 AM
I don’t pay much attention to the “list” or imager ratings but this thread piqued my interest so, I took a quick look at it. Here’s what I see:
📷 image.pngIt seems really curious that out of the top-ten, five users have ZERO IOTD awards and very few other awards. Number four on the list has won just two top picks, has 1764 followers and he has made only16 posts. I’m not trying to pick on anyone but if this list is supposed to be somehow ranking the top imagers, either the algorithm assigning the ratings isn’t looking at the right things or someone somewhere is somehow gaming the system. As it stands, this list seems pretty meaningless—other than perhaps to provide a quick summary of imager stats. But maybe I don't understand it. What is the ranking supposed to be showing?
John

John. This new rendition of the List has been improved by re-weighting the point impact of collaborations, which i think is appropriate. What you have pointed out is, I think another aspect that needs an adjustment.

The current algorithm seems to consider the number of likes totals with fewer images posted, as a positive. I suppose as an indication of consistency.

Another oddity is that some imagers have huge numbers of likes on images that are reposted as new that are actually revisions of the data according to the rules.

scott

Getting back to the underlying topic of discussion here - which is index points awarded for collaboration photo "likes" are now split between the collaborators. As someone who is under skies where the seeing alternates between a semi-translucent colloid and plain old mud, I have not, and am likely not going to be a part of any collaboration due to what results in suboptimal data. I would love to, but my skies are not likely to produce anything a team can't live without. I therefore have no real dog in the fight (I know, "fight" is a little hyperbolic) other than the abstract gain of roughly 250 spots on the AP image index since the collaboration "likes" were split up. That said, if that bump in the index rankings that people get from receiving full "like" credits for collaborated images encourages people to continue to collaborate, then why change it? While I have not looked at it empirically to compare individual vs collaborated images where new discovery is concerned, the one discovery I can think of right off hand was made by a collaboration team. Are there teams out there that are, to borrow a term from earlier in the thread, "gaming the system". That's not likely a motivation to add what seems like another layer of difficulty to image submissions.

While it will be at a detriment to my own image index ranking, I would recommend keeping collaborated "likes" at the higher rate to continue to encourage collaboration. Or, and I'm just spit-balling here, rank collaborations separately.