Kan: Difference between revisions

'''Kan''' {{kana|カン}} is a special [[naki|tile call]] in the game. This call forms a [[mentsu|tile grouping]] of four identical tiles, called '''kantsu''' {{kana|槓子}}. Just like all tile calls, the call itself is optional; thus, an opportunity to call kan is not mandatory.

While appearing as a four-of-a-kind, the tiles used to form kantsu actually function as a [[koutsu|three-of-a-kind]] plus one extra tile. With that in mind, tiles called for kan still interpreted as "triplets" particularly for [[Yaku#Triplet|triplet-based yaku]], such as [[toitoi]] and [[sanankou]]. For every kan declaration, players are required to take an extra tile draw from the [[dead wall]]. This drawn tile is called the '''[[rinshanpai]]''', or '''dead wall draw'''.  After the kan call and player's discard, then another [[dora|dora indicator]] is revealed.

The call for kan is a discretionary play, with its own set of rules and restrictions.  Under all circumstances, a player may call kan or decline when given the opportunity.  The strength of kan play stems from the exclusive access to the dead wall and the revealing of additional dora.  At the same time, kan play is very risky, where other players may end up as the benefactors. Therefore, players may decline calling the kan to minimize risk.  Choosing to do so or not, this play does require some assessment; and players are not encouraged to make such calls recklessly.  On the other hand, players may rely on kans, when it is needed.

Like the other tile calls, kan is also a tile call. However, it comes with special properties and rules. These rules apply when a player possesses or gains possession of four of the same tile; and then the player makes the kan call.

# The four identical tiles are shown and are set aside, like an open call. Together, the four tiles now count as one [[Mentsu|tile group]].

A special case may involve the yaku, [[chankan]]. If the kan call involves a shouminkan and the added tile is a winning tile for another player, then chankan may be applied upon the declaration of another player's winning hand. In this case, the hand ends before the player even gets to draw the extra tile from the dead wall. Thus, the process of calling kan gets interrupted in favor of another player's winning hand.

The call for kan reveals additional dora, in the form of [[dora|kandora]]. The timing of this reveal is variable, depending on [[Dora variations|the rule set and/or game platform]].  The simplest rule invokes an immediate reveal upon the declaration; and so, this rule would immediately place the kan reveal after step 1. Others distinguish the timing between open and closed kans. Here, closed kans would be granted an immediate reveal; however, open kans would produce another kandora indicator after the discard, upon conclusion of the kan process at step 8. Regarding the timing of the kandora, players will need to consult organizational, tournament, and/or local rules.

*Closed triplet with the fourth tile type discarded

*Open triplet with the fourth tile type drawn

*All four tile types drawn

If in possession with the proper tiles, a player may call kan more than once consecutively.  The extremely rare case of up to four consecutive kan calls within a single turn is possible.

As for kan dora, ankan (closed kan) is the only case, where a new indicator is shown immediately after the kan call. Otherwise, the number of kan indicators is one less than the number of kan consecutive calls. In the case of the above example, two added kans were called sequentially; but only one kan dora indicator was shown upon winning the hand.

Kan calls after riichi is possible and may be allowed or disallowed depending on the hand's composition. Under all of these cases, the call for a closed kan is used.  The other two types of kan calls cannot occur, as riichi requires closed hand.

When a riichi declarer holds three identical tiles and draws the fourth after the riichi announcement, the player may form an [[Kan|ankan]] from these tiles instead of discarding the fourth. The hand composition and the possible winning tiles may not change: it is not allowed to declare kan if, for some possible winning tile, any of the three identical tiles may be interpreted as part of a [[shuntsu|sequence]] or part of the pair.

Of course, a player may outright decline the call for kan and discard the drawn tile.  After all, the play invokes a risk pertaining to the kandora. During a riichi call, the player is defenseless against the benefactors of the new dora.

It is not allowed to kan the fours. The manzu tiles may either be interpreted as a 3-4 [[Ryanmen|ryanmen]] wait and a 4-4 pair, or as a 4-man ankou with a 3-man [[tanki]] wait. A kan call would alter the wait just for a 3-man tanki. For a legal kan declaration, the three identical tiles would have to be an ankou in any interpretation. Had the player drawn a west wind, he would have been allowed to kan it.

:{{#mjt:3335666p111456s}} Illegal kan: {{#mjt:36p}}

Here, the waits are 457p. A kan on 6p would remove the 7p wait, so it is obviously not permitted. A kan on the 3p would not change the waits, however, if the hand was won with 4p, the hand could be interpreted as:

In this case, the 3p does not form a [[koutsu|triplet]], but rather a pair and a part of a sequence. A kan on the 3p would remove this potential interpretation of the hand, and is therefore forbidden.

:{{#mjt:222333444p23m11z}} Illegal kan: {{#mjt:2p}} {{#mjt:3p}} or {{#mjt:4p}}

In this case, a kan call on any of the pinzus would leave only the three triplets interpretation possible. Thus, any of these kan is deemed illegal after riichi, even though it doesn't change the waits.

This is an "abortive draw" regarding kan calls.  From the dead wall, only four tiles can be used for the extra draw, or '''rinshanpai'''.  The remaining tiles from the dead wall are used as dora indicators, or they are tile replacements from the regular wall.  Neither of these two tile type can be used in play.  As a result, the limit of kan calls for a hand session is set to four.  After the fourth kan call, the [[hanchan|kyoku]] (hand session) ends after the discard, barring that discard cannot be called for a win.   

However, an exception is made for players with [[suukantsu]] tenpai.  After the fourth kan call, the game continues, giving the player a chance to score the yakuman. Under many rulesets, the other players are not allowed to call a 5th kan to invoke the abortive draw. Some [[rule variations]] may allow a 5th kan to immediately end the game in a draw.<ref>https://youtu.be/eds4GAKPlOc?t=5m7s</ref>

The nature of [[dora|kan dora]] makes the call for kan a risky maneuver.  With this in mind, some quick assessment is needed before making such a call.