Tile efficiency: Difference between revisions

'''Tile efficiency''' refers to the speed of '''hand development'''. Having better tile efficiency means that the hand is more likely to complete, and is thus faster on average.

==Tile categories==

Isolated tiles, also known as "lone" or "floating" tiles, are those with no neighbors. A tile is isolated when there is no tiles numerically or categorically adjacent. Therefore, they may not be used for [[naki|tile calls]].  

===Taatsu===

{| class="wikitable" width=40%

|-

!Incomplete

|}

===Toitsu===

{{main|Toitsu}}

===Complex joints===

{| class="wikitable"

!Type

|-

!Incomplete

==Important concepts==

===Isolated tile utility===

In order of least useful to most:

{| class="wikitable"

!Type !! Pair !! Ryanmen !! Kanchan !! Penchan !! Total

|-

|-

!3 thru 7 ({{#mjt:3p}})

|}

[[Yakuhai]] are a special case. Because they can be [[pon]]'d to instantly gain a yaku and a group, they are more valuable when these conditions are met: 1. the hand would not have any yaku if opened, 2. the hand does not have an obvious "4 groups + 1 pair" yet, and 3. creating a triplet is possible (less than 2 copies are visible). In an average starting hand, they are more valuable than 1/9 but less important than 2/8. Yakuhai are a bit stronger in [[tonpuusen]] due to its faster paced nature.

===Five-block theory===

Example hand split into blocks:

* {{#mjt:12367m23p334s334z}} can be split into:

To see why 5 blocks is important, look at these example 2-shanten hands:

{| class="wikitable"

!# Blocks !! Hand !! Tile acceptance

|-

{| class="wikitable"

!# Blocks !! Hand !! Draw !! Discard !! Tile acceptance

|-

**You can upgrade one of your joints (e.g. turning a 45 ryanmen joint into a 445 complex joint).

**You enter 1-shanten.

*When discarding the 6th block, discard the weakest block you have (the one that improves tile acceptance the least). For example, if deciding between a penchan and ryanmen, discard the penchan. If you have two blocks of 23-man + 56-man, they have "duplicate acceptance" on the 4-man, so discarding one of those only leads to a loss of 4 tiles of acceptance.

*You may want to keep 6 blocks when aiming for a yaku, such as [[pinfu]] or [[sanshoku]].

A hand needs 1 pair to win. If the hand's only pair turns into a triplet, you'll need to make a pair elsewhere, or break the triplet later. When you have 2 pairs, either pair can be turned into a triplet freely, thus increasing tile acceptance by 4. When you have 3 pairs, one extra pair can be turned into a triplet, increasing tile efficiency by only 2. Therefore, keeping 2 pairs (ideally 1 as part of a 'ryanmen + pair' complex joint) is strong. Refer to the following tables:

{| class="wikitable"

!# Pairs !! Shape !! Tile acceptance

|-

|-

|2 || {{#mjt:22p22m000000000z}} || {{#mjt:2p2m}} (4 tiles)

{| class="wikitable"

!# Pairs !! Shape !! Tile acceptance

|-

|1 || {{#mjt:23m22p78s0000000z}} || {{#mjt:14m69s}} (16 tiles)

|-

|-

|}

When you are likely to [[pon]] one of the triplets (e.g. [[yakuhai]] pair), then keeping 3 pairs can be good, since you'll be at 2 pairs once you make the pon.

If you have 4 pairs you might want to consider [[chiitoitsu]], but if a sequence or triplet forms, you should probably discard a pair and go for a normal hand. At 5 pairs, you're at 1-shanten for chiitoitsu, so you should likely go for that.

==Yaku==

In other cases, players may end up simply having tenpai in mind, especially as the hand nears the later discards. This is of particular concern for the current [[dealer]], who may have an interest in retaining the position and [[Renchan|repeat the hand]].

== External links ==