Short version
Having finished below diamond 5 in the previous season I obtained the correct number of bonus stars (9) but upon reaching diamond 10 in the current season I lost two stars instead of one, resulting in having zero bonus stars at diamond 10-5. This happened for the past two seasons (April and March 2021).
Long version
In March 2021 (season 84) I finished at Diamond 4 and obtained the correct amount of bonus stars for the following season (April), 9 as according to Hearthstone own technical support article.
In the following season (April) everything went smooth until reaching the Diamond 10 floor after which I noticed that I had zero bonus stars. To clarify, a victory gave me a single star and victory during a win streak gave me two stars.
There are a total of 8 rank floors between the initial Bronze 10 and the Diamond 10 (Bronze 5, Silver 10, Silver 5, Gold 10, Gold 5, Platinum 10, Platinum 5 and Diamond 10) meaning that out of the initial 9 bonus stars I should have left one last bonus star between ranks Diamond 10-5 (as it was the case since the introduction of this new system).
I contacted the game support through a ticket and they say they couldn’t help me because they are lacking the tools to view or edit the bonus stars associated with my account.
Thinking it might have been a temporary bug associated with the release of the new expansion, I let it slide and reached Diamond 2 (again, April) without using the bonus star that I deserved. With the new season (May), I received again the correct number of bonus stars (9) at the start of the season but the same bug happened at Diamond 10 and I am now at Diamond 10-5 missing a bonus star.
I can provide screenshots for proofs both for the finishing ranks and for the missing bonus stars.
Bronze 10 - you started with 9 stars
Bronze 5 - lost one = 8
Silver 10 = 7
Silver 5 = 6
Gold 10 = 5
Gold 5 = 4
Platinum 10 = 3
Platinum 5 = 2
Diamond 10 = 1 star only
It feels everything is ok.
It is not entirely clear from that support article, but if you check https://playhearthstone.com/en-gb/news/23357896 (mentioned in the article), you will see that “This Star Bonus acts as a multiplier on the Stars you earn from each win. For example, if you have a Star Bonus of 5x and you win a game, you’ll get five Stars instead of one.”
Your math is correct but you forget that these are bonus stars. So yes, at diamond 10 you are left with one bonus star to be added to the regular star that you get from winning for a total of 2 stars per win.
I have obtained sub Diamond 5 every season for the past 13 seasons and I always had a bonus star at Diamond 10, so I am pretty sure that is a bug. Patch notes for Barrens do not mention any change either by the way.
Ok so the current system was introduced in season April 2020 right after Ashes of Outland (season 73 as absolute number) and we are going to call it season 1.
Since then I obtained sub Diamond 5 (between 5 and 1) for seasons 1-5 (included), legend rank for seasons 6 and 7, and then again sub Diamond 5 for seasons 8-13 (the current one).
That would mean that since season 1 I had the bonus stars corresponding to a legend rank (10) MMR despite not reaching the rank itself for 5 more months (half a year) and then again for an entire year after the last time I obtained the legend rank. And all of this without noticing. That sounds fishy, as you can see.
Thanks for trying to help but I would like to receive an official answer from Blizzard technical support (since in-game support was not able to help at all), which is a simple matter of
- Validate that the MMR I received for the end of season April 2021 matches with the bonus stars received in the following season of May 2021.
- Validate that bonus stars are additional and not multiplicative (i.e. a bonus star means a total of two stars per win)