KenKen or KenDoku is a style of arithmetic and logic puzzle invented in 2004 by the Japanese math teacher Tetsuya Miyamoto, an innovator who says he practices "the art of teaching without teaching". He intends the puzzles as an instruction-free method of training the brain. The names Calcudoku and Mathdoku are sometimes used by those who don't have the rights to use the KenKen or KenDoku trademarks.

The name derives from the Japanese for .

As in sudoku, the goal of each puzzle is to fill a grid with digits –– 1 through 4 for a 4×4 grid, 1 through 5 for a 5×5, etc. –– so that no digit appears more than once in any row or column (a Latin square). Grids range in size from 3×3 to 9×9. Additionally, KenKen grids are divided into heavily outlined groups of cells –– often called “cages” –– and the numbers in the cells of each cage must produce a certain “target” number when combined using a specified mathematical operation (either addition, subtraction, multiplication or division). For example, a three-cell cage specifying addition and a target number of 6 in a 4×4 puzzle might be satisfied with the digits 1, 2, and 3. Digits may be repeated within a cage, as long as they are not in the same row or column. No operation is relevant for a single-cell cage: placing the "target" in the cell is the only possibility. The target number and operation appear in the upper left-hand corner of the cage.

In the English-language KenKen books of Will Shortz, the issue of the non-associativity of division and subtraction is addressed by restricting clues based on either of those operations to cages of only two cells. Some puzzle authors have not done this and have published puzzles that use more than two cells for these operations.

History

In 2005, toy inventor Robert Fuhrer encountered KenKen books published in Japan by the educational publisher Gakken Co., Ltd. and titled . Fuhrer's company Nextoy, LLC (now holder of a trademark on "KenKen" and "KenDoku" as a name for brain-training puzzles) and chess International Master Dr. David Levy helped bring the puzzles to the attention of Michael Harvey, features editor of ''The Times'' (London). Harvey, impressed with what he calls its "depth and magnitude", arranged for publication of such puzzles, starting in March 2008, in ''The Times''. Other papers, including the ''New York Times'', followed suit. KenKen now appears in more than 40 newspapers in the United States, as well as numerous international publications.

Example

The objective is to fill the grid in with the digits 1 through 6 such that:

Each row contains exactly one of each digit

Each column contains exactly one of each digit

Each bold-outlined group of cells is a cage containing digits which achieve the specified result using the specified mathematical operation: addition (+), subtraction (−), multiplication (×), and division (÷). (Unlike Killer Sudoku, digits may repeat within a group.)

Some of the techniques from Sudoku and Killer Sudoku can be used here, but much of the process involves the listing of all the possible options and eliminating the options one by one as other information requires.

In the example here:

"11+" in the leftmost column can only be "5,6"

"2÷" in the top row must be one of "1,2", "2,4" or "3,6"

"20×" in the top row must be "4,5".

"6×" in the top right must be "1,1,2,3". Therefore the two "1"s must be in separate columns, thus row 1 column 5 is a "1".

"30x" in the fourth row down must contain "5,6"

"240×" on the left side is one of "6,5,4,2" or "3,5,4,4". Either way the five must be in the upper right cell because we have "5,6" already in column 1, and "5,6" in row 4.

etc.

Extensions

More complex KenKen problems are formed using the principles described above but omitting the symbols +, −, × and ÷, thus leaving them as yet another unknown to be determined.

The restriction of puzzle size to the range two through nine is not absolute. A KenKen of size two is of little value even as an example, as it can immediately be solved by trying the two possibilities — ones on the "rising" diagonal and twos on the "falling" one, or vice versa. But extension beyond nine presents only difficulties of calculation with larger numbers, and the need, in recording possible values, to avoid confusing multi-digit numbers with items in a list of single digit ones.

References

External links

kenken.com (official site)

Puzzle Guru Will Shortz, ''Time Magazine'', March 2, 2009

Category:Mathematics and culture Category:Logic puzzles

de:Ken Ken es:Kenken fr:Ken-ken it:KenKen ja:賢くなるパズル pl:KenKen sl:KenKen zh:算獨

Coordinates	54°33′″N36°17′″N
name	Daigo Umehara
url	daigothebeast.com
birth date	May 19, 1981
nickname	The Beast
status	Active
hometown	Tokyo, Japan
country	Japan
leagues	Super Battle OperaEvolution Championship Series
years	1995-present
games	''Street Fighter II Turbo''''Street Fighter III 3rd Strike''''Street Fighter IV''''Street Fighter Alpha 3''''Darkstalkers''''Capcom vs. SNK 2''''Guilty Gear''''Capcom Fighting Evolution''''Marvel vs. Capcom 3'' }}

Daigo Umehara (梅原 大吾 ''Umehara Daigo'', born 19 May 1981), is a renowned Japanese arcade fighting video game player. He specializes in 2D arcade fighting games, mainly those released by Capcom. Known as "Daigo" or "The Beast" in the west and "Umehara" or "Ume" in Japan, Umehara is one of the world's most famous Street Fighter player and is often considered its greatest, as well. He currently holds a world record of "the most successful player in major tournaments of Street Fighter" in Guinness World Records.

Before properly being called a progamer from signing a sponsorship deal with MadCatz, Japanese media usually referred to Umehara as "God of 2D fighting games" (2D格闘ゲームの神 "2D Kakutou Game no Kami").

Early career

Umehara began going to an arcade game center and playing fighting games at around 10 years of age when he was an elementary school student, the same time when Street Fighter II and Garou Densetsu (Fatal Fury) hit the game center. Because the SF2 cabinet had a very long line and also had older kids playing, his first fighting game is actually Garou Densetsu. Because there was usually a long line in his free time and he could not stay too late, Umehara first started challenging other players in Street Fighter II Dash (Champion Edition) even though he felt shy and had to ask for permission to challenge first, but that was also when he started to like playing with other players.

Around the time when he was a 13-year-old middle school student, Umehara shifted his main game to Vampire Hunter because he thought he did better than SF2 and first developed some reputation by setting a 286-win streak record before he was forced to leave due to closing time at Akihabara Sega (now Club Sega) game center. He first joined a tournament when he entered GAMEST Cup's national Vampire Hunter tournament in 1995, though he lost in the block's finals. His second tournament and also his first tournament winning is GAMEST Cup's national Vampire Savior tournament in 1997 where he defeated Ōnuki (now Nuki) in the finals.

In 1998, Umehara participated Capcom's official ''Street Fighter Zero 3'' national tournament and advanced to the finals which took place on a stage in Tokyo Game Show 1998: Autumn on October 11. After winning the tournament by defeating Ōnuki 3-1, as the champion, Umehara went on to face Alex Valle, who was the winner of the U.S. national ''Street Fighter Alpha 3'' tournament. The international "Grand Championship" was held in San José, California on November 8. This is Umehara's first trip to U.S. and first overseas tournament. The match was played as best out of three games, with each game as best out of five rounds. Umehara came from behind to win 2-1;These two events received a 50-minute TV coverage in Japan.

In September 2001, Umehara gained enough fans to have a book about him published. The title is VERSUS, also known as "Umebon" (ウメ本) or "Ume Book." It contains both his background and stories behind his competitions and opponents.

In 2002, Umehara appeared in U.S. versus Japan theme exhibition matches in Japan. American players competed in four games (''Super Street Fighter II Turbo, Street Fighter Alpha 3'', ''Street Fighter III 3rd Strike'' and ''Marvel vs. Capcom 2'') for the right to battle Japan's best players in those respective games. Umehara only entered the ''3rd Strike'' exhibition, but defeated all of his opponents, ending each round with Ken's fierce Shoryuken. These events were filmed for the documentary ''Bang the Machine''.

In 2003, Umehara won Super Street Fighter II Turbo tournament in the first Super Battle Opera (Tougeki) and won the same game in Evolution Championship Series when he joined the event for the first time in the same year, making him the first player to win both SBO and Evolution in same year on the same game. Umehara also went to Evolution 2004 and Absolution 2004 on April 18 in England and won SSF2 Turbo there.

Umehara has participated regularly in a number of tournaments, appearing at least one each year since beginning in 1997, with a brief hiatus in 2008.

The dramatic comeback at Evolution 2004

Umehara started becoming famous internationally from the YouTube video clips of his match in the Losers bracket final in Evolution Championship Series 2004's Street Fighter III: 3rd Strike competition where he made a dramatic comeback against Justin Wong's Chun-Li. In the final round of match 1, Umehara's Ken was down to his last pixel of vitality. At this point, any special attack would knock Umehara's character out if connected, since special attacks deal chip damage even when blocked. In an attempt to win the round, Wong attempted to hit Umehara's Ken with Chun-Li's multihit Super Art move ''Houyoku-sen'' (鳳翼扇, "phoenix-wing fan"). However, instead of avoiding it, Umehara chose to "Parry," a technique whereby an incoming attack is blocked without the player losing any health, but by doing so requires moving toward opponent's direction in the same time a hit lands, within four of thirty frames per second of the impact animation. After the move was launched, not only were all 15 hits Parried, but Umehara also managed to get into a good position to make a powerful attacking combo that knocked Chun-Li out instead. This moment, and the ecstatic cheering of the spectators that followed, was recorded and later spread on the Internet, gaining immense popularity.

NHK's TV program, MAG-NET, has called this moment "Kiseki no Gyakuten Geki" (奇跡の逆転劇) or "The miraculous reversal play".

Street Fighter IV era

In July 2008, Umehara came out of retirement and aims for competition once again. This time, his focus was on the newly-released Street Fighter IV. Because of this, Japanese arcade gaming magazine Arcadia has included a DVD featuring "Umehara Concept Matches" in its January 2009 issue (released on November 29, 2008) and "The God has returned" was stated in Umehara's player introduction part. The DVD contains exhibition matches between him and Japan's 6 top players such as Inoue, Itabashi Zangief, Fuudo, Nemo, and Mago.

2009

On March 5, Umehara made an appearance as the "God of fighting games world" in a TV show "Gamer's Koshien". He and the fellow Japan's 4 top players (Soushihan KSK, Itabashi Zangief, Mago, and Tokido) had to compete with each other and with celebrities in a Street Fighter IV round-robin tournament where the top players had to win the amateurs overwhelmingly in order to get a good point as a handicap.

On April 18, at GameStop's Street Fighter IV National Tournament 2009, Francisco, California, there was exhibition matches between 4 players from 3 countries after the actual competition ended. It featured Iyo who had recently won the Japanese National SF4 tournament, Poongko who won the Korean SF4 National Tournament, Justin Wong who won the American National SF4 tournament, and Daigo Umehara who came by Capcom's invitation. Umehara defeated Iyo, Poongko and Justin Wong to win the tournament. He was awarded a free trip to Evolution 2009 in Las Vegas.

Umehara began writing a column in Arcadia starting from the August issue, called Umehara Column: Michi. ("Umehara Column: Street")

For his win at the GameStop tournament, Umehara started his Street Fighter IV competition as a seeded player in the semi-finals on July 18, which is the second day of Evolution 2009. In the third and the last day, Umehara defeated Justin Wong and put him into the Losers Bracket, then advanced to the grand finals just to meet Wong again. The two fought until the last game possible, but Umehara won the competition.

The September issue of Arcadia magazine included a DVD featuring the second of "Umehara's Concept Matches" which is the sequel to the DVD from late 2008. This time Umehara had to fight Japan's 5 top players: Mago, Iyo, Nuki, Nemo, and Shirou.

On August 7, Umehara participated in an all night tournament called "GODSGARDEN."

Umehara participated in exhibition matches in a Street Fighter IV competition in Taiwan on October 10.The matches were broadcasted live on Famitsu's web channel.

Umehara went to America again to join a tournament called Season's Beatings on October 16–18 in Columbus, Ohio. He won Super Street Fighter II Turbo HD Remix and Street Fighter IV Singles competition.

On November 26, Umehara and 5 other top Japanese Street Fighter IV players joined a Nico Nico internet live show to talk about the second GODSGARDEN tournament. The show also held an exhibition match between himself and Mago.

2010

Instead of participating GODSGARDEN #2 (March 6), Umehara flew to France to enter Street Fighter IV tournaments in World Game Cup gaming event that took place between March 3–7. He finished the second place in singles and first in 2 on 2.

Umehara and two teammates participated official Street Fighter IV National Tournament and qualified to the top 14 on April 4. His team was eliminated in the quarter finals. The competition was broadcasted live on Nico Nico.

Umehara went to America to join Capcom's Super Street Fighter IV "Fight Club" launch party in Los Angeles on April 23. The party held exhibition matches in which he played various characters including Hakan, Guy and Dee Jay against a dozen of challengers. The event ended with a 3-out-of-5 match, between him and Justin Wong. Their draw result from double K.O. at the end left Umehara undefeated in that night.

It is also revealed in the event that Umehara accepted a sponsorship deal from Mad Catz and will play under their name in the future tournaments.

The limited edition of Super Street Fighter IV game from e-CAPCOM store comes with a special DVD featuring two tournaments between Japan's 8 top players: Umehara, Tokido, Iyo, Shirou, Kin Devu, Momochi, Tokidoki Nukings, and Itabashi Zangief. The first one is a "new character only" tournament where Umehara played as Adon. The second one is for old characters. The Super Street Fighter IV Technical Guide published by Enterbrain which was released on April 28 includes a DVD featuring exhibition matches of the new characters played by Japan's 7 top players: Umehara, Tokido, Kin Devu, Iyo, Momochi, Itabashi Zangief, and Shirou.

On May 9, Umehara made his appearance as the "Super Player" on an NHK's Sunday night program "MAG-NET" which had a scoop on Street Fighter. The show told the story about his fame (including his 2004 dramatic comeback), his life, his competitions and his opponents. There was also Umehara's tutorial session where he demonstrated his arcade stick gripping method called "Umehara Mochi" (ウメハラ持ち) or "Umehara Grip" and his signature Ryu's combo technique—Shouryuken > Focus Attack Dash Cancel > Metsu Hadouken.

On May 15, Nico Nico Live held a Super Street Fighter IV online competition where participating online players on Xbox Live got a chance to fight Japan's 3 top players: Umehara, Mago, and Tokido. They also have offline matches and a short talk corner.

Umehara went to Australia for the first time when he participated Evolution Asia Pacific's Super Street Fighter IV tournament in Sydney on May 29–30. He won the tournament losing just one game and, as the grand prize, earned a paid flight to Evolution 2010 in Las Vegas where he will start off as a seeded player.

On June 4, Umehara joined the 106th Xbox Live Park online event held by Microsoft Japan with Famitsu's editorial department. Participating Xbox Live Gold members got a chance to have a Super Street Fighter IV online match and chat with Umehara in the 2-hour period.

After the invitation to play in Electronic Sports World Cup (July 3–4) was cancelled and after getting the 2nd place in Nagoya Street Battle 15 (July 4), Umehara joined Evolution 2010 between July 9–11 and faced a tougher challenge than before with over 1,700 players from around the world participating in the Super Street Fighter IV tournament. However, without going down to Losers bracket, Umehara won the tournament in front of ten thousands of audiences both in the hall and in front of computer screens. The live stream of the event set a new record with approximate 48,000 viewers at peak 2 channels combined (Stickam 18,000 and Ustream 30,000) during the SSF4 grand finals before it went down due to technical problems.Umehara also received Evo exclusive golden arcade stick with serial number 1 as a prize.

After winning the qualifier on May 22, Umehara's team participated in the Super Battle Opera 2010's Street Fighter IV finals on September 19 and won the second place. The event took place as a part of Tokyo Game Show 2010 at Makuhari Messe International Convention Complex. A pay-per-view live stream was distributed by Nico Nico.

Umehara participated in Season's Beatings tournament in Ohio for the second time between October 15–17, Southern California Regionals tournament in Los Angeles between November 6–7, Canada Cup in Canada between November 13-14, and Northern California Regionals tournament between November 20-21. He then went to Kuwait for an exhibition event on November 26.

Achievements

{|class="wikitable sortable" !Year!!|Tournament!!Game!!Place!!class="unsortable"|Note

|- |2011|| Evolution 2011||Super Street Fighter IV: Arcade Edition||4th|| |- |2011|| NorCal Regionals 9||Super Street Fighter IV: Arcade Edition||1st|| |- |2011|| ReveLAtions||Super Street Fighter IV: Arcade Edition||1st|| |- |2011|| Topanga Charity Cup||Super Street Fighter IV: Arcade Edition (5 on 5)||1st|| Teammate: Tokido, Mago, Nyanshi, Bonchan |- |2010|| NorCal Regionals 8||Super Street Fighter IV (3 on 3)||1st|| Teammate: Ricky Ortiz, fLoE |- |2010|| NorCal Regionals 8||Super Street Fighter II Turbo HD Remix||1st|| - |- |2010|| The Canada Cup||Super Street Fighter IV||1st|| - |- |2010|| The Canada Cup||Super Street Fighter IV (3 on 3)||3rd|| Teammate: Air, Mago |- |2010|| The Canada Cup||Super Street Fighter II Turbo HD Remix||1st|| - |- |2010|| SoCal Regionals 2010||Super Street Fighter IV||2nd|| - |- |2010|| SoCal Regionals 2010||Super Street Fighter II Turbo HD Remix||1st|| - |- |2010|| Season's Beatings V||Super Street Fighter II Turbo||1st|| - |- |2010|| Nagoya Street Battle 17||Super Street Fighter IV (3 on 3)||1st|| Teammate: MACHI, Momochi |- |2010|| Super Battle Opera 2010||Street Fighter IV (3 on 3)||2nd|| Teammate: TKD, Bon-chan |- |2010|| Ayano Cup||Street Fighter IV (5 on 5)||1st|| Teammate: Nyanshi, Misse, Nemo, Iyo |- |2010|| Super VS Battle 20-X||Super Street Fighter IV||3rd|| - |- |2010|| Evolution 2010||Super Street Fighter IV||1st|| - |- |2010|| Nagoya Street Battle 15||Super Street Fighter IV (3 on 3)||2nd|| Teammate: Mago, Tokido |- |2010|| Evolution Asia-Pacific||Super Street Fighter IV||1st|| - |- |2010|| World Game Cup 2010||Street Fighter IV (2 on 2)||1st|| Teammate: Eita |- |2010|| World Game Cup 2010||Street Fighter IV||2nd|| - |- |2009|| Seasons Beatings IV||Street Fighter IV||1st|| - |- |2009|| Seasons Beatings IV||Super Street Fighter II Turbo HD Remix||1st|| - |- |2009|| Seasons Beatings IV||Street Fighter IV (3 on 3)||3rd|| Team: Daigo Company |- |2009|| Shiozawa Cup||Street Fighter IV (5 on 5)||1st|| Teammate: Nyanshi, Misse, Iyo, Bon-chan |- |2009|| GODSGARDEN #1||Street Fighter IV||3rd|| - |- |2009|| Evolution 2009||Street Fighter IV||1st|| - |- |2007|| 2nd Darkstalker Combination Cup||Vampire Hunter||1st|| - |- |2007|| Hyper-Mania 4||Hyper Street Fighter II (Team)||2nd|| - |- |2007|| X-Mania 7||Super Street Fighter II Turbo (Team)||2nd|| - |- |2006|| Evolution 2006||Guilty Gear XX Slash||2nd|| - |- |2005|| Super Battle Opera 2005||Street Fighter III: 3rd Strike (2 on 2)||1st|| Teammate: Nuki, Team: UmeNuki |- |2005|| Super Battle Opera 2005||Capcom Fighting Jam (Team)||2nd|| - |- |2004|| 4th Cooperation Cup||Street Fighter III: 3rd Strike||1st|| - |- |2004|| Absolution 2004||Super Street Fighter II Turbo||1st|| - |- |2004|| Absolution 2004||Guilty Gear XX #Reload||1st|| - |- |2004|| Absolution 2004||Street Fighter III: 3rd Strike||1st|| - |- |2004|| Absolution 2004||Street Fighter Zero 3||3rd|| - |- |2004|| Evolution 2004||Super Street Fighter II Turbo||1st|| - |- |2004|| Evolution 2004||Guilty Gear XX||1st|| - |- |2004|| Evolution 2004||Street Fighter III: 3rd Strike||2nd|| - |- |2004|| Kakutou Ishin||Street Fighter III: 3rd Strike||2nd|| - |- |2004|| Kakutou Ishin||Street Fighter Zero 3||2nd|| - |- |2003|| Evolution 2003||Super Street Fighter II Turbo||1st|| - |- |2003|| Evolution 2003||Guilty Gear XX||1st|| - |- |2003|| Evolution 2003||Street Fighter III: 3rd Strike||2nd|| - |- |2003|| Evolution 2003||Capcom vs. SNK 2||2nd|| - |- |2003|| Super Battle Opera (#1)||Super Street Fighter II Turbo (Team)||1st|| Teammate: Kurahashi, Otochun |- |2003|| Super Battle Opera (#1)||Capcom vs. SNK 2||2nd|| - |- |2000|| Official National Tournament||Capcom vs. SNK||1st|| - |- |2000|| 3rd Official National Tournament||Street Fighter Zero 3||1st|| - |- |2000|| X-Mania 2000||Super Street Fighter II Turbo (3 on 3)||3rd|| - |- |1999|| Official National Tournament||Street Fighter Zero 3 (Team)||2nd|| - |- |1998|| Official National Tournament||Street Fighter Zero 3||1st|| International Champion |- |1997|| GAMEST Cup||Vampire Savior||1st|| - |-class="sortbottom" |}

Most of data from 2007 and older is provided by beastdaigo.jp. Complete list and more data on smaller-scaled tournaments can be found on the Japanese fan site. All data is verified by sources as of May, 31, 2010. Reports from official sites are included if available. Only first, second, and third place are displayed here.

See also

Street Fighter

Electronic sports

Nico Nico Douga

References

External links

Daigo Umehara's official homepage / Daigo Umehara's Japanese fan site Daigo Umehara related articles on Japanese gaming magazines

Category:1981 births Category:Living people Category:People from Tokyo Category:Arcade games Category:Electronic sports Category:Super Battle Opera tournament winners Category:Competitive video gaming Category:Street Fighter

de:Daigo Umehara fr:Daigo Umehara nl:Daigo Umehara ja:梅原大吾 pt:Daigo Umehara sv:Daigo Umehara vi:Umehara Daigo