Manila starts!

Launch time!
Competitors can now hit the seas and head to Manila!

manilaoffbanDetails are at the ABOUT MANILA page on the menu above, give it a good read before starting at the HARBOUR. Some of the puzzle ideas and examples were taken from Ko Okamoto, Nikola Zivanovic, Serkan Yurekli, Riad Khanmagomedov and WPC 2011 Hungary.

Manila will be opened for 29 days ending on the 8th of June.
Any questions can be made here:

I’m looking forward to sending, not one, but three of you, prizes next month.
Happy Mother’s Day!

*** At just over 20 hours of launching, Manila Bay Pier has already welcomed its first competitor! Looking forward to see more of you! ***

Next destination: Manila

My next event is inspired by the board game Manila.

61NFQ9DRTML._SY300_The year is 1821 and under the rule of the Spanish crown, you are orchestrating secret trades with other tribes in mainland Asia. Using punts, you load your boats with four precious commodities: coffee, ginseng, jade and satin. These will be worth a living once they are successfully smuggled out to Manila.

In the game, you have to deviously plan which commodity to take, how you’re going to navigate the boat and be careful of notorious pirates. You could also bribe pilots to give you a ride to Manila.

I will incorporate all these elements into a puzzle adventure…

manilabannerAll of the puzzles, except one, are logic-based and will be language-neutral. However, due to the narrative nature of the event, some reading may be required. I did my best to keep it as simple as possible for non-English speakers so everyone should be able to enjoy Manila.

Also you can contact me throughout the event with any help you need, big or small.
One last good news; this event will have 3 prize winners!
Your chances have just tripled!

See you in Manila!

24HPC recap without the puzzles

[Personal recap of the 24HPC]


Budapest Ferenc Liszt Airport

On the forward trip, I sat next to a Turkish college student who was studying in Hungary. I asked what “Akil Oyunlari” meant in Turkish. He said “umm…like brain games”. He was born in Antalya so I was like, “hey, that’s where they hosted the 2009 WPC”, which was an excuse to explain why I was going to Budapest to solve puzzles. Pushing my luck of shoving puzzle talk to a stranger’s face, I also asked if he knew who Serkan Yurekli was. And I got a positive response!
“Yeah. He was on TV one time, I think he makes puzzles right?”
I admit I’m terrible at coming up conversation topics.

Like last year, I was the first to arrive and the last to leave Budapest. It certainly helps to spare a couple of days rinsing off your jet lag, especially when one had just covered over 17,000km in about a day and half. My first priority of looking for non-sparkling water was achieved at a dairy just across the road. Illiterate in Hungarian had me buying bagfuls of snacks based solely on its marketing appearance. I did enjoyed most of them fortunately.



The next day, I met Tom and Neil at breakfast and had plans for two escape games in the city. We went early in case of the very likely event of us getting lost, which meant we had a good hour munching on coffee and cake at a lovely store next to the location of the first escape game.

We were joined by the German puzzle team of Silke, Robert and their friend Hammond. The first game was held in a quiet residence and was hosted by a polite woman who apparently wasn’t the host of the English-language version, but we can agree that she did a fantastic job running the game.


On board the SS.Elzzup!

As with all escape games, the theme was loosely-based on a narrative. Hell, I can’t even remember the theme now. A friend is getting married in France? Somehow you’re on a boat to New York? He was framed for something? We needed to find a train ticket? A ring? Oh, I give up.

[Spoilers ahead: if you plan to play an escape game in Budapest, you might suddenly be the most competent member of your team]

So the first room was decorated like a boat and we had to find 5 coins to open up the next room. It wasn’t obvious, but there were 5 “things” to do and it was sensible to assume that they run independently and each lead to a coin. We had no system going in, everyone just solved whatever they felt like they could. All I can recall was peeking through a chest to see a picture of a sailor, holding a mop and hitting a seagull. On the ceiling was a seagull and there was a mop lying on the floor. The clever trick was that the mop was magnetic and it had to drag a key from a ledge on the ceiling. Going on simultaneously in the room, was a map puzzle being solved to unlock a rope ladder which Robert had to climb to a balloon which contained a coin.


Tom’s head on a bus

The second room was the train scene. We had to fill a briefcase with the correct set of five items to finish. There was an invisible code written on the mirror that Neil helped me solve, a classic logic puzzle that Hammond and I solved, while others revive a dead cellphone to get specific time schedules for a train ticket hidden behind a picture. There was a dummy in the room (I think it was the ticket collector) which we mercilessly murdered because what else do you do in escape games? You flip the whole room upside down and look into every inch of every single item that was there. The dummy’s head rolled right off by the time we finished.

We clocked in at 36-37 minutes, without hints, and were told that the current record was around 34 minutes. Ah, we did great. Afterwards, we returned to the same café (called Death by Decaf) for seconds and headed to the next escape game. It was held in a spacious cellar (or “dungeon”, as Neil insisted). The theme this time was that we had to stop a biotechnical warfare by finding some sort of poison concocted by some mad professor. The room was his lab and there were heaps of things to solve.


We had better times

My favourite had to be where a box was opened by placing a stethoscope on to the heart of a skeleton. Several puzzles ended up adding one piece to a chessboard so we incorrectly assumed that the chessboard was probably the last thing to be solved and proceeded to solve other puzzles in the room. We burnt at least 20 minutes trying to figure out how to make sense of colourful chemicals on the table and got nowhere.

We had to phone for help and the host directed us to “a green monster”. There was a green rubbish bin and surely enough, magnetized to inside of the lid was the crucial final chess piece. Gahh, honestly we must’ve opened that bin at least five times each. Good warm-up for the 24HPC.


Another 300 or so puzzles to understand the rules of


Listening to my occasional sighs; my table neighbour Matthew Stein from USA.

Fast forward to the end of the competition, I left Budapest for Dubai. The purpose of entry on my VISA was cultural/sports which prompted “what sport were you playing in Budapest?” at the customs. I thought for a second before replying, “puzzles.”
Of course I got a confused look.
“Like sudoku”
That elicited an “Ahh… I know sudoku. Wait. You flew all the way from Auckland to solve sudoku?”


The newly renovated competition room meant generous working space for us

In Dubai, I tried their Snooze Cube, which was a little bedroom for transits. Air-conditioned, free Wi-Fi, universal outlets and the room goes pitch black when the lights were switched off. Absolutely perfect.




I listended to a few podcasts and slowly nodded off…


Home time!


Quiet Melbourne Airport at 5am

After two more transits at Melbourne and Auckland. One last domestic flight carried me home.


No more planes for me.
Until next time!

Nikola, Robert and Zoltan tops 15th 24HPC

10395820_826304097429959_4078698941160149976_n The 15th 24 Hour Puzzle Championship is already behind us and I had a blast! Undisputed winner Nikola Zivanovic was in a league of his own and soared away from the competition very early on, earning another (his second or third?) victory at the 24 HPC. The race for second place was won by the very consistent Robert Vollmert. Zoltan Horvath, who came straight from his third place win at the Poland Championships, rounded off the three podium finishers.

Left-Right: Robert Vollmert (Germany), Nikola Zivanovic (Serbia), Zoltan Horvath (Budapest) [Photo courtesy of:  Rejtvényfejtők Országos Egyesülete]

Left-Right: Robert Vollmert (Germany), Nikola Zivanovic (Serbia), Zoltan Horvath (Budapest)
[Photo courtesy of: Rejtvényfejtők Országos Egyesülete]

Speaking of consistency, I scored 774 (just 3 point less than my last year’s score) appropriately finishing at the exact same position: 12th place. A clear and mildly depressing indication that one year went by with no improvement whatsoever. My thumb is still numb from 24 hours of pencil-gripping.

Full results

Full results

Big thanks to the organizers, authors and the lovely company of Neil, Tom, Liane, Michael, Rob, Adam and Katrina for such an amazing weekend. 11095083_878410352219333_6284051748742055371_n A little funny story before ending this post. Our booklets are returned after each round and at one point, Neil’s had “Sorry, no points” written in red pen next to a sad face. Wondering for a second why he wasn’t awarded his points for the Futoshiki, we realized that he was solving the accompanying example! Even better, the answer was right next to it! I have another 24-hour adventure in the form of 4 long flights back to New Zealand starting tomorrow. Only this one, I’m not looking forward to with as much enthusiasm.

15th 24HPC this weekend


The 24 Hour Puzzle Championship has reached its 15th edition this year and is happening this weekend. I will be taking part for the second time so if you’re making the trip I’ll see you there!

Last year after hanging around in the top 10 most of the time, I ended up at 12th likely due to the many 5 minute naps that I stole during the early morning rounds. The podium spots are personally unrealistic for now so I hope to just improve on my last year’s numerically-beautiful score of 777.

Ever since I knew about the 24HPC, flicking through the newly-released instruction booklets was an exciting moment to look for new puzzle ideas. Now that I’m fortunate enough to participate, it won’t be a casual browse anymore!

The very first Minesweepers with Duds coming to Hungary.

Instructions for Minesweepers with Duds

A little bit about my set: every year I more or less follow a prototype of my original set back in 2010. A new variant this time is the Minesweepers with Duds which the harder one will be worth the most points in my round. I will be eager to see if anyone can haul in the maximum 1000 points in those 100 minutes. Very plausible.

Safe travels and see you in Budapest!

Post Excavation #2

Many solvers made a comment on the Killer Sudoku – either it was unreasonably hard or it was one of the most beautiful puzzles they have ever solved. Couldn’t tell whether you did the right thing, huh?

I met up with Sinchai at the annual Thailand Puzzle Open last month and we went through the Killer Sudoku together at McDonalds. Here are some of his notes on his own puzzle:

A: If 9 is placed in the 13-cage, it will need to be grouped with 1 and 3 (to get 13). We know 1 has to be in one of the top three cells (since 1s will be in the 7-cage and the 8-cage). Therefore, the 9 has to be in R9C9.
B: 1 cannot be in the 15-cage because it will need to be grouped with either: [9 and 5] and we can’t use the 9 or [6 and 8] and we can’t use them since the 22-cage will either need [9,7,6] or [9,8,5]. Lastly, the 7 can be placed by adding the regions to get 45.


C: 1 can be placed in the 8-cage.
D: Take a look at the bottom row: the two uncaged squares and one cell in the 13-cage has to contain 6, 7 and 8 since they can’t be anywhere else in that bottom row. Note that 6 and 8 can’t both be in the 13-cage. Since we see the 23-cage needing 9, 8 and 6 – R9C3 has to be a 7.
E: 1 is forced to be in the 15-cage and has to be grouped with either [9 and 5] or [6 and 8]. If [6 and 8], we can see that the first column will have no place for both 6 and 8. Therefore the 15-cage has to be comprised of 1, 5 and 9.
F: The three blank squares of the top left 3×3 box must add up to 24, namely; 9, 8 and 7. Using simple slice and dice we can fill in those 3 cells.

killans3G: After you fill in 9, 8 and 7. Relay the information down to the 23-cage at the bottom. You can see the third column can be broken down into unique pairs; which leaves a 2 at R4C3. (H)
The 8-cage houses 1, 2 and 5 so it will share 1s and 2s with the 7-cage at the bottom. The 5 and 4 must be in the same column, therefore you can now place the 3 and 5 of the bottom left 3×3 box.
J: That leaves 3 and 4 in the 2nd column marked as shown with 6, 7 and 8 remaining in the 1st column.
K: Only possible location for the 9 at the left-middle 3×3 box.
killans5L: Still keeping track of the 9s, you can see that the three uncaged cells of the upper middle 3×3 box adds to 22, which needs a 9. The only place for the 9 in the 6th column is therefore, R4C6.
M: Careful here. The 3 has to belong in either the 13 or 15-cage. If the latter, there is no way to get 15 using [3,?,?]. There are no more big numbers available. So the 3 has to go to the 13-cage.
N: Similarly, the 5 can’t also go to the 13-cage as [3,5,?] needs another 5 to get 13. Therefore, the 5 goes to the 15-cage.
O: As we’ve pointed out earlier (at step D) that R8C4 has to be 6, 7, or 8. The 5 has to go in the 8-cage, making [1,2,5]. Now, several cells can be filled in.killans6P: 2 is forced by the 7 and 8-cage to be in the 15-cage making [2,5,8]. The 13-cage is therefore [3,4,6].
Q: 8 can be filled in R9C4 leaving [6,7,9] for the 22-cage. 3 and 4 can be placed in their uncaged cells.

We’ll leave it here for now.
Those were Sinchai’s initial steps and from here on he believes simple notations should get you through the whole puzzle. A very tough Killer Sudoku indeed.

The solutions to all the puzzles have been combinsudoked into this PDF

Post-excavation #1

All the Sudoku Excavation pages at the menu have been taken down. You can still get the puzzles here:
Large 9×9 puzzles
Small 6×6 puzzles

Solvers were asked to guess the authors of the puzzles, scoring points by doing so. Here’s a rule of thumb: if the sudoku is of a math-related variant, contains little givens and is frustratingly difficult then you can sanely bet that Sinchai wrote it. The guy loves solving and making math-variant sudokus. Or he just likes mathematics. Did you know that he scored 100% in our country’s Mathematics National Entrance Examination? Well, you do now.

You can see the rule in effect since Sinchai was responsible for the murderous Killer, Fortress and Sum 100. Others include Thermometers, XV and Consecutive. I wrote all the small puzzles (except the Consecutive), Kropki, Even Odd, Arrow and the final Mammoth fur puzzle.

Speaking of the last puzzle, Mark Goodliffe says that it’s always so much more fun when a puzzle (hunt) builds towards a finish.
I agree!

A very diligent Nick Brady: I did this in one session lasting about 7 hours and had much fun with it.
Now you know what to do on your next intercontinental plane trip.

Ivan Koswara: I just threw the Classic Sudoku to some online solver.
You cheater, you.

James McGowan: Can I assume Tamziania is somewhere near where you live?
Tamziania is a Google Map snapshot of the hospital car park where I am currently studying (and losing most of my sleep) at. As a shout-out, I also plan to use you dearest readers as characters in future events. Keep an eye out for yourself!

Zbigniew Laskowski: I thought I would become a killer myself when I received the killer clue from Fortress and realized that I had spent so much time solving that killer without the clue.
You can hunt down Sinchai for that, I’d never do such a thing to my readers. :)

Extra thanks to all solvers who fill in the comments box, my favourite part of an event is selecting some of them to post at the end (like the few above). So that’s my side of things. Sinchai might have a few words when his boss isn’t requiring his attention.

Results of Sudoku Excavation

One month just flew by didn’t it? 28 solvers headed out to Tamziania, dug up fossil pieces, assembled the Sudoku Mammoth and eventually conquered the mighty beast. Here is the list of solvers in the order of submission: Swaroop Guggilam, Fred Stalder, Stefan Tomlins, Zoran Tanasic, Oliver Rubio, Antonis Lalatsas, Branko Ceranic, Valerie Alexandre, Nikola Zivanovic, Valerie Garcia, Matt Stephans, Nick Brady, Franck Wallez, Prasanna Seshadri, Neil Brown, Todd Geldon, Mark Goodliffe, Eva Myers, Joshua Zucker, Sumet Juariyamark, James McGowan, Ivan Koswara, Zbigniew Laskowski, Rakesh Rai, Stefano Forcolin, Grayson Holmes, Manea Constantin and Bastien Vial-Jaime.
*[ETA: Fixed typos]
finalpuzzlesudex At the conclusion of our exhausting project, I asked solvers to guess who wrote the puzzles that form the fur of the Sudoku Mammoth. Since me and Sinchai aren’t that prolific (yet), most of the responses were probably guesses anyway. Certain points were allotted for each correct guesses and the maximum total is 50 points.
Note that all the point values in the table below are doubled (since I got lazy with decimals) but this doesn’t affect the standings.
Here are the results with the top 5 being omitted: sudexressneak Please don’t be discouraged by the standings, as they are most likely to be guesses and someone has to win. So who’s missing? 
Let’s introduce our top 5:
First to submit was Swaroop Guggilam, he was either the first or second to send in an entry throughout last three events. What an early bird! Coincidentally, second to submit was Swiss sudoku legend Fred Stalder, one of my favourite sudoku authors. This is his first entry at SOTR. He writes for many offline and online venues and all the puzzles are collected in his blog; and you can find that address in my blogroll. Two more newcomers made it to the top 5; one is Valerie Garcia; thanks to Fred who posted about it in the French forum, she and several other French names found out about our expedition. The next lucky newcomer is Stefano Forcolin who I’ve met and exchanged a few words with at the 2013 WSC. Lastly is Eva Myers, she made it to the final 8 of rock-paper-scissors way back in the first Nikoli Hurdles, good to see her back!
Now the final results…! sudexres Congratulations to Valerie Garcia from France scoring a whopping 94/100!
Interesting that Fred actually had more correct guesses at 9/10 but Valerie’s total is one point (initially 0.5 before the double) higher. More interesting is that one more competitor also scored 8/10, which is Zbigniew Laskowski who ended up at 6th place because his two incorrect guesses were worth higher points.

Again, all points were random and pre-determined which shows how it came down to luck for this little prize draw. For winning, Valerie will receive the Mammoth Book of New Sudoku by Gareth Moore. We have now come to the end of Sudoku Excavation. I will post solutions and comments about the whole event throughout the next few weeks. I would to thank co-author Sinchai and all 28 of you who’ve made this event so enjoyable.

Construction of my next event is already underway and it is scheduled for April. All I can say is it will include a variety of puzzles combined into one nice little theme. Pop back here for more details or subscribe to get notifications in case you forget!

Bye for now!

Final week for Sudoku Excavation

We are now approaching the final week of Sudoku Excavation. If you are still out there digging in Tamziania, you have a few days left to go. All submissions that I have received thus far are replied with a confirmation e-mail.

Apologies for late replies, I’m usually much more active online than this, so these confirmation emails may take up to 3-4 days.

If you’ve entered and have not heard from me, please check that your email address is spelt correctly in the submission form and try submitting again.