User:Kashi/Jun'i-sen

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Kashi/Jun'i-sen
Category Qualifier for the Meijin-sen
Outline
Time held June - March
First held 1947 (term 1)
Time control 6 hours per side
Organizer(s) Mainichi Shimbun
Asahi Shimbun
Japan Shogi Association
Official site https://www.shogi.or.jp/match/junni/index.html
Records
Notes
  • Longest stay in class A: Yasuharu Oyama
    (44 terms)
  • Longest continuous stay in class A: Yasuharu Oyama
    (44 continuous terms)
Show template

The Jun'i-sen (順位戦 Jun'isen) or Ranking League is a tournament hosted by the newspapers Mainichi Shimbun and Asahi Shimbun in cooperation with the Japan Shogi Association, which acts as a qualifier for the Meijin-sen. The player with the best record in class A will challenge for the Meijin title.

Summary

The league consists of 5 classes A, B1, B2, C1, and C2. The top finisher of class A will become Meijin challenger. Even though the Meijin themselves do not participate in the league, their years as Meijin are counted as years in class A as well when calculating career records.

Each class normally conducts a round-robin tournament from June to March of the following year, from which the seeds of next year's league are decided. Most new professionals start their career in class C2, with some starting in Free Class instead (not participating in the league). Current rules do not allow skipping classes in promotion, which means that new players have to play for at least 5 years from their debut to challenge the Meijin.

Players can be promoted by moving up classes in the league, with their game fee earnings also increasing depending on their class. Other than revenue, players in higher classes also benefit by being exempt from certain preliminary rounds in other tournaments. However, a player can be forced to retire immediately or after a fixed time if they lose rights to participate in the league, a trait not seen in any other tournament.

Around the first third of March every year, all 5 games of class A's last round will be played on the same day, and most of the time the Meijin challenger and the 2 demotees will only be decided then. Due to the long duration of the games, this day is called "the shogi world's longest day", attracting attention outside of the shogi world as well. From 2014 onwards, with the exception of 2017, these games have all been played at the Fugetsuro restaurant in Aoi Ward, Shizuoka City, Shizuoka Prefecture. These games are analyzed live on giant boards at the JSA headquarters in Sendagaya, Tokyo, the Shogi Kaikan at Fukushima, Osaka, and the Osu Hall at Naka, Nagoya. They are also streamed live on TV and online.

From term 66, the Mainichi Shimbun and the Asahi Shimbun have cooperated to host the tournament. On even-numbered terms, Asahi will be listed as the first sponsor and on odd-numbered terms the Mainichi Shimbun will be listed first.

System

Classes and promotion/demotion

The system is comprised of the 5 classes A to C2, along with Free Class players who will not be playing. The player with the best result of class A gains the right to challenge the Meijin.

Each class's mechanics are described below. Classes that have empty slots (due to players retiring or passing away) will be adjusted on a case-by-case basis.

Current rules

Class Capacity Game count Promotion Demotion/demotion points
Meijin 1 Best-of-7 match with the challenger Title is defended after winning 4 games against challenger Return to class A after losing 4 games (as seed 1)
A 10 Round-robin + Playoff

9 games + BO7 match (challenger)

(for challenger)

Title is acquired after winning 4 games against Meijin

2 players[1] (to B1)
B1 13 12 round-robin games 2 players (to A) 3 players (to B2)
B2 no fixed capacity 10 games with other players in same class 3 players (up 1 class) Players with 2 accumulated demotion points (down 1 class)
C1
C2 Players with 3 accumulated demotion points (to Free Class or retirement)
Free Class Demotees from C2 no games

(participation in other tournaments still possible)

Satisfy at least 1 promotion requirement (to C2) Up until either one of the below, whichever is faster:
  • Stayed in Free Class for 10 years
  • End of season where player reaches 60 years of age

If a promotion requirement is not satisfied during the period above then the player must retire after they have finished all games in official tournaments.

Voluntary

transfer

Can't return to league After a certain number of years (1-8) have passed the player will retire after either of the below is satisfied, whichever is faster:
  • End of season where player reaches 65 years of age
  • Another 15 years have passed

Demotion points (for classes B2, C1, C2)

Requirement for accumulation
  • Class B2: The formula for number of players receiving demotion point is (players in class / 4)[2].
  • Classes C1/C2: The formula for number of players receiving demotion point is (players in class / 4.5)[2].
Requirement for removal
  • For class C2, removal of demotion points is limited to players with 2 points only. The 1st demotion point will never be removed if the player doesn't promote/demote.
  • A player can get a demotion point removed if they end the league with more wins than losses or finish 5-5 2 years in a row.
  • If a player meets both the requirement for accumulation and removal of points in the same season, there is no change to said player's status.
  • When a player promotes or demotes, their demotion points are reset to 0.

Headbumping

When multiple players share the same result, with the exception of a tie for Meijin challenger, no playoff will be held. Instead, players will be ranked based on their seed from the start of the season to determine those who promote and those staying behind. When such an event happens, for lower-seeded players failing to promote, it is called headbumping (頭ハネ atamahane)[3]. The contrary is also true: players can remain or suffer a demotion point based on seed alone, hence a single win in class C2 can later affect one's remaining or demoting from class A.

In class A of the 27th Ranking League held in 1972 contested by 11 players, Rensho Nada 8-dan, who was on break last term, finished 9th overall. Normally, this meant that he was among the 3 players to be demoted, but Nada was not demoted due to his 5-5 result. Regarding this, on the 4 April 1973 issue of the Asahi Shimbun, Nada has said that it "would have been a big problem if 5-5 finishers were demoted". A description of this rule was also found in the August 1958 issue of the Kindai Shogi magazine, indicating that it had been known among players for a long time. However these rules did not exist on paper and the JSA did not have these rules either. As a result, in the 76th Ranking League, where class A was also contested by 11 players, the JSA, the Mainichi Shimbun, and the Asahi Shimbun agreed that if this were to occur again, the player would still be demoted as per usual. On the JSA's website, this was demonstrated with a hypothetical playoff of all 9 players who finished 5-4. If a potential demotee failed to challenge the Meijin, they would still be demoted anyway.

Exceptions related to promotion

Generally, classes B2 to C2 will have 3 promotees each (from term 79). If the number of players finishing 10-0 exceeds the amount of slots, from term 77, it has been clarified that all 10-0 finishers will be promoted regardless of seed. Before this clarification, there has been no cases of this occuring. There will be no problem if this occurs in classes C2 or C1 as the classes above them both have no fixed player count. However, if this occurs in class B2, next term's class B1 will have an excess amount of players. For example, if 4 players in class B2 finished 10-0, class B1 will play with 14 players next term, and 4 players will be demoted next term. As for classes B1 and A, since these classes play round-robin, there will never arise more than one 10-0 finisher.

Adjustments related to over/undercapacity classes

Classes A and B1 have a fixed capacity, which means that problems can arise from one of the causes below.

  • Overcapacity classes
    • Players returning from break.
    • (only for class B1) More than 3 10-0 finishers promoting from class B2. See Exceptions related to promotion.
  • Undercapacity classes
    • Players retiring/passing away before the draw is conducted, leading to a deficit in their classes.
    • Players retiring/passing away in the midst of a league, leading to the rest of their games being treated as a no-show win for their opponents, and the class they promote/demote to or remain in will have a deficit.
    • (only for class B1) Deficit in demotees due to players on break in class A.
    • (only for class B1) Players voluntarily transferring to Free Class.

At the beginning of the season, if there is a player deficit/surplus, the number of demotees will be adjusted accordingly so as to return to the normal capacity. For example, if class A has 11 players, 3 players will be demoted, and if it has 9 players, 1 player will be demoted. Class B1 will also take into account the extra/missing demotees from class A if this occurs.

Players on break

If for unavoidable reasons such as illness, a player can submit a notice of absence in the 1-year period before the next league to be excluded from all tournaments in that season. If this happens, the player will not be demoted in their first season of absence and will be assigned the lowest seed in their class when they return. This is called "overhang" (張出, haridashi). If they return in class A, class B1 will play with a player deficit and class A with a surplus. However, if the player is absent for 2 years or more, they will start demoting if in class A or B1 and receiving demotion points if in class B2 and below. After they have been absent from class B2 for 3 years, they will directly demote regardless of demotion point count. However, if a player decides to go absent in the middle of a season, the rest of their games will be ruled as a default loss and they will be demoted/promoted as per usual.

If a player passes away in the middle of a season, the rest of their games will also be ruled default losses, with their opponent receiving a default win. However, the deceased player's losses will not count towards their career statistics. If a player is promoted by way of a default wins against a deceased player, their date of promotion will be the scheduled game date.

Challenger-deciding playoff

If there are multiple players with equal results for the top spot in class A, a ladder-style playoff will be conducted, with the lowest ranked players at the bottom and the highest ranked player at the top.

There have been 21 playoffs held since the new system was established in term 5. Of these, 5 were held with 3 players and 4 with 4 players or more. The most players to have played in the playoff is 6 (in term 76).

3-man playoff (5 terms)

Terms 7, 12, 44, 45, and 61 (seasons 1953, 1958, 1986, 1987, and 2003 respectively).

4-man or more playoff (4 terms)

With the exception of Yoshiharu Habu Ryuo in term 61, no challenger selected via 3-man or above playoff has defeated the reigning Meijin in the title match.

  1. If a player in the demotion zone happens to enter the playoff and challenge the Meijin, the player with the next lowest seed will be demoted instead.
  2. 2.0 2.1 Rounded down to the nearest integer.
  3. Based off the same term in Riichi mahjong.
  4. Class A had 11 players this season.