Thank you for testing and for reporting the problem with Firefox. We can replicate the problem using Firefox as well. But at this point, we are unable to provide a fix for the same.

We have added the corresponding note in the submission page that Firefox is not supported.

Can the contest please be extended over a period of few days (maybe 3) like we had for the WS+PC ? I am keenly interested to participate (officially) but would be extremely hard pressed to take all rounds tomorrow.

For International players, dates will be Dec 12 - 16, right?

The WS+PC wasn't an official World Championship so we had some leeway. I doubt there are official National Championships that don't have a fixed time, online or not.

Question: In Round 3 Online Solving will the Sudokus still show up one at a time as in the trial?

That is correct. International participants can start upto 11:59PM on 15th December.

Yes, they will show up one at a time.

No. All ISC/IPC finals in the past have been under fixed time window. For official entries, Indians need to participate in the specific window mentioned in IB.

I don't know if anyone reported this yet, but in R2: Prime Sum Sudoku - Rules say "marked by white circles", but in the puzzle there are black diamonds.

Attachments
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Results after Round 1.pdf (144KB - 76 downloads)

Attachments
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Results After Round 2.pdf (144KB - 61 downloads)

Note: If you are Indian and don't see your name in the results, you need to go to your profile and add your country as India.

Attachments
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Final Results ISC and SM 2021.pdf (162KB - 98 downloads)

A big thanks to the organizers for putting this together. It was a lot of fun!

I messed up Prime Sums in Round 2, but I doubt that would have changed anything, probably just made it a closer race :) Congrats to Rohan for the win! I feel a lot better this year than the past two years where it was more me creating my own problems, nothing wrong in being beaten by a truly excellent performance.

Hearty congrats to Nityant and James who both have shown improvement in only their second ISC, great showing by them. Especially with the lesser rounds, my feeling is Round 3 definitely gave the edge to the experienced WSC participants, so its great that you two kept the pace there.

Congrats to the other winners, Kishore and Aashay, too.

A wonderful set of puzzles. Thanks to the Authors, testers, organizers, and LMI for putting this together.
I for one appreciate online solving availability because of no printer.
I messed up Round 2 big time by breaking 4 puzzles and needing to resolve them. Round 3 was definitely my favorite with great interactions across puzzles and nifty idea.
Congratulations to all the winners (ISC and SM). This is my personal best rank at ISC, so I am happy with that.

Thank you to everyone who was behind this event. It was an amazing experience for me.
Round 3 was a new concept for me and it took some time for me to fully understand the rules and tricks. It was a very close race towards the end.
This was my first time getting a rank in an official competition, so I'm pretty satisfied with that
Congrats to all the other winners!

A huge thanks to the organizers, authors and testers for yet another fantastic ISC. I messed up big time in R2. I loved the concept of R3, thought I found the Hundred Sudoku quite challenging. As fun as this event was, I sincerely hope this is the last online ISC and we can have an offline event next year, as nothing beats interacting with fellow Sudoku enthusiasts!

Thanks to all the organizers for conducting a smooth and successful ISC. Congratulations to Prasanna and Kishore for the podium!
Great job by Swaroop as well finishing a close 4th. Shoutout to Nityant and James for a terrific performance and Aashay to complete the SM winners. Hope to see you at WSCs soon.

Puzzle quality was high and all 3 rounds were enjoyable. Some of my favourite sudokus:
Palindrome Arrow 50-50
Equations
Hundred
Sequences

I didn't quite like that there were just 3 rounds this year. It's too less for a final event that aims to provide a similar experience of an offline finals.
Most of us take two days leave (or break from routine) to travel to another city to compete for an offline finals. I'm sure we could arrange an 8-hr time slot at the comfort of our homes (or places of choice).
But well, lets hope we can resume offline finals from next year. Always a pleasure to meet up with everyone for the fun weekend event.

And of course, my recurring feedback each year that the SM base points are so negligibly low that there is very less incentive to participate in the online rounds. It should at least be equal to one round (points in the range of 300-600 as per this year's scale)

The integration of Penpa is fantastic. While it might provide a little edge to online solvers, I think the positive of enabling more players to compete outweigh the negative. So kudos for the work on this.

Once again a huge thank you to all the authors and test-solvers for the time and effort put into this event.

A huge thanks to all organizers and authors involved in putting together this fantastic ISC. I really appreciate the efforts being made to conduct online ISC finals over the past 2 years so that the essence of an offline event is not completely forgotten. Congrats to Rohan for a dazzling performance and to Prasanna for putting up a spirited show. Well done Swaroop for finishing a close 4th.

Special congrats to Nityant and James Peter ! You guys really made the scoreboard merry and more lively and gave a complete scare :). All the very best to keep improving your skills !

I only wish my performance lived up a bit more. Although, I would admit that it was a complete relief to finish in top-3, I honestly feel that with those total points, a third was not deserved given that there is a huge difference in points (around 1200) between 1/2 and 3. Mental note to myself to read rules more carefully and thoroughly in future and not to goof up Rounds.

Favourites of each round :

R1 - Pencilmarks and Killer
R2 - Equations and X-Sums
R3 - Clone and Hundred

R3 was a fun and very nice set to solve. Good luck to all for IPC :)

Thanks to the organizers, authors, and testers for the great puzzles for ISC. All the Sudoku puzzles were of very high quality. My favorite is R3 with a good concept. Rohan and Prasanna's performance is awesome. Looking forward to IPC next week :).

Video on Hundred Sudoku from R3

https://youtu.be/xhmyfelFt-I