Clarifications from the Q&A session:

1) "Official" round timings: The official start timings for each round will be strictly followed for each round as in IB page 2.
2) Odd Even Bridge: It is possible that the numbers on a bridge can all be of the same parity.
3) Odd Even Bridge: If the circle has an odd digit, the count of odd numbers on a bridge is done based on the number of instances of odd digits on the bridge, not just the number of different digits. If 7 appears twice it ill be counted twice. Same for even numbers in a circle.
4) Morse Numbers Sudoku: The Morse codes will be the same as in IB.
5) Quadruple Sudoku: If a number appears twice in a clue it must appear 2 times in the 4 adjacent cells.
6) Hidden Arrows Sudoku: Each cage will be in the shape of a snake. and the arrow can be in either of the two directions. Multi-digit circle clues are possible but multi-digit numbers on the arrow line are not possible.
7) Sum Detector sudoku: The digit in a cell with an arrow can be sum of 'n' digits, where 'n' can be any number from 1 to 5.
8) Clone: The clone shape will be horizontally and vertically connected.
9) In round 5, there will be no bonus even if one sudoku is incorrect.
10) Adobe Flash Player will be needed to participate in this contest.

not enabled for me

unable to start the round

how do i submit the answers? do i type all the digits/letters in the row/column as the answer or?

There are marked rows/columns for each sudoku, you need to type in those digits in the corresponding answer key on the contest page. Refer to IB for example.

Edited by swaroop2011 2020-12-13 5:23 PM

Please do not share scores as the contest is on till 16th December.

Congratulations to the winners. I am very happy with my performance and this is my personal best rank in ISC.
A wonderful set of puzzles and of great quality. A day well spent, or should I say night for me.
Kudos to all the organizers for making this event go smoothly. It was a very close experience to an offline final.
Kudos to all the Authors for amazing Sudokus and also testers for ensuring the quality and difficulty of the puzzles.
Eagerly waiting for the next weekend.

What a fantastic collection of Sudokus! Kudos to all the authors, test solvers, and others involved in putting this together in spite of all the challenges this year presented.

I thoroughly enjoyed it. Round 1 was a nice warmup, rounds 2 and 3 were typical rounds you'd expect and then rounds 4 and 5 were a nice change of pace for the post lunch session. Very nicely mimicked the offline experience as far as that could be done.

Congrats to Rohan and Aashay!

Personally it is sad that I missed out in the last round again, but no matter, another year another lesson :)

Congratulations to the winners and also to first-timers who managed to spend an entire day solving Sudokus in a competition setting! A huge shout out to the authors - Akash, Rakesh, Priyam, Kumaresan, Nikola, Tawan, Jan and Cedomir and all the test solvers for a fantastic set of Sudokus. I absolutely enjoyed solving all the rounds. Also, heartfelt thanks to the organizers - Rakesh, Priyam, Amit and others who made sure that the competition went smoothly.

Phenomenal organization by Rakesh, Akash, Priyam, Kumaresan, Amit and all the foreign contributors! The sudokus were of very high quality and the whole experience of mimicking an offline finals was a huge success.
I've never liked online championships but this one is an exception.

Congrats to Prasanna and Rishi for the podium and to Aashay, Jayant and Shambo for topping SM. It's a pity there are no playoffs, they are always fun to watch. Let's hope we return to normalcy next year.

My favourite sudokus:

R1: Killer
R2: Unordered Distances
R3: Odd Labyrinth
R4: Perfect Squares
R5: Core

A big thank you to all core organizers Rakesh, Amit, Priyam, Kumaresan and Akash for making this event possible in an otherwise gloomy year. Special congrats for putting out the set without any broken sudokus! Tremendous effort !
Heartfelt thanks to all authors Akash, Cedomir, Jan Novotny, Nikola, Priyam, Kumaresan, Rakesh and Tawan. Sudokus were of a very high quality and were challenging and really enjoyable :) .

A Very big thank you to all the organisers for a wonderfully organized event. Like others have already mentioned it perfectly mimicked the offline event. The sudokus were of great standards and were really fun to solve. I just loved the mean minis, though my score for that round is a silly goof up from my end and not a reflection on quality of the sudokus :D Great job guys and congrats to all the winners :)

Thank you to all the organisers and the authors for organizing such a flawless online event with such amazing sets of sudokus. Thoroughly enjoyed the whole of it.
Congratulations to all the winners.

At least with way too many puzzles for the time limit (for my skill level) I was able to pick the ones I thought I'd be best at. Was ... 'mostly' right, but I did mess a few up. I have to say, the mechanism for distribution, timing, and submission with instant grading is pretty superb!

I thoroughly enjoyed the event. Its first time and havent given five rounds in a stretch till now. Whatever I had solved, it had beautiful solve paths. I loved the Core sudoku in the last round, the way the loops interacted to get the numbers. Its a beautiful construction. solved or attempted maximum 5 or 6 sudokus in any round. So others must also be constructed with interesting logical solve paths. will try others leisurely.

Seeing these many sudokus in all the rounds, with the testing behind and some sudokus might have not been considered, cannot imagine how many would have been constructed and how much coordination was required to handle the event so smoothly. It really shows the backend effort.

Kudos to all the authors and organizers!!

I enjoyed the event immensely. I am sure there was a lot of hard work put in by the organisers and the authors, and this effort is very much appreciated.

This was my first ISC and it was an extremely interesting day. The puzzles were great and the organizing was so smooth without any glitches. Big thanks to the puzzle creators and testers and the whole team of organizers! You deserve a great applause.