Matagi suji: Difference between revisions

Latest revision as of 16:44, 29 August 2024

Matagi suji, or "straddle suji", is a form of discard reading. It states that, when a number tile is discarded early, nearby tiles become safer. But, when a number tile is discarded late (especially if the riichi declaration tile), nearby tiles become more dangerous.

When a tile numbered 3-7 is discarded, the tiles within +/- 2 of that tile are affected by matagi suji.
When a tile numbered 2 or 8 is discarded, the 1-4 or 6-9 tiles are affected by matagi suji.

Table

Discard	Remaining in Hand	Matagi suji
2	23	1-4
3	23 or 34	1-4, 2-5
4	34 or 45	2-5, 3-6
5	45 or 56	3-6, 4-7
6	56 or 67	4-7, 5-8
7	67 or 78	5-8, 6-9
8	78	6-9

Theory

Matagi suji relies on the power of a shape like "233" or "334". When a player has a "233", it is unlikely for them to discard a 3 early - turning "233" -> "23" - since it'd come at a loss of tile efficiency. So if a 3 is discarded early, it is less likely for them to have "23" (which waits on 1-4) or "34" (which waits on 2-5) remaining. Therefore, an early discarded 3 makes both 1-4 and 2-5 safer. Note: tiles towards the outside of a discarded tile (1 & 2 in this case) are much safer; tiles towards the inside are not much safer than a regular tile.

Conversely, it is more likely for a player to keep shapes like "233" until just before tenpai. So if a 3 is discarded as the riichi declaration tile, it is more likely for them to have a "23" or "34" remaining. This means a late discarded 3 makes 1-4 and 2-5 more dangerous.

Note: if the riichi declaration tile was a tsumogiri tile (discarded right after drawing it), then tiles near the last non-tsumogiri tile become dangerous instead.

Effectiveness

"Tiles nearby the riichi declaration tile" are more dangerous. But, when folding, there usually isn't a need to consider matagi suji. A 4 discarded as a riichi declaration does make the 5 more dangerous, but a non-suji 5 is already very dangerous. It can make an impact when deciding whether to push or fold, though.

"Tiles outside of early discards" are relatively safe; about as safe as regular suji (but a bit less safe).

External links

Matagi suji danger analysis on Path of Houou
Matagi suji on Mahjong Gem

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-{{Stub}}
+'''Matagi suji''', or "straddle suji", is a form of [[discard]] reading. It states that, when a number tile is discarded early, nearby tiles become safer. But, when a number tile is discarded late (especially if the [[riichi]] declaration tile), nearby tiles become more dangerous.
-'''Matagi suji''' is a specific [[suji]] read that examines tiles near numbered tiles.  It can be referred as "straddle suji".  For numbers 3-7, they point to numbered tiles -2 or +2 away from them.  For 2 and 8, they point to tiles 1-4 and 6-9 respectively.
+*When a tile numbered 3-7 is discarded, the tiles within +/- 2 of that tile are affected by matagi suji.
+*When a tile numbered 2 or 8 is discarded, the 1-4 or 6-9 tiles are affected by matagi suji.
 ==Table==
@@ Line 22: / Line 23: @@
 |}
-==Usage==
+==Theory==
-The concept behind matagi suji considers a discarded tile as an interior tile to a waiting [[shuntsu|sequence]] in the hand.  The idea may not be applicable to early discards, particularly first row.  Players may not be [[tenpai]] at that point.  Regarding [[tile efficiency]], tiles discarded later may indicate potential tenpai shapes.  They were kept long enough until no longer needed because of favorable draws.
+Matagi suji relies on the power of a shape like "233" or "334". When a player has a "233", it is unlikely for them to discard a 3 early - turning "233" -> "23" - since it'd come at a loss of [[tile efficiency]]. So if a 3 is discarded early, it is less likely for them to have "23" (which waits on 1-4) or "34" (which waits on 2-5) remaining. Therefore, an early discarded 3 makes both 1-4 and 2-5 safer. Note: tiles towards the outside of a discarded tile (1 & 2 in this case) are ''much'' safer; tiles towards the inside are not much safer than a regular tile.
+Conversely, it is more likely for a player to keep shapes like "233" until just before [[tenpai]]. So if a 3 is discarded as the [[riichi]] declaration tile, it is more likely for them to have a "23" or "34" remaining. This means a late discarded 3 makes 1-4 and 2-5 more dangerous.
+Note: if the riichi declaration tile was a tsumogiri tile (discarded right after drawing it), then tiles near the last non-tsumogiri tile become dangerous instead.
+===Effectiveness===
+"Tiles nearby the riichi declaration tile" are more dangerous. But, when [[fold]]ing, there usually isn't a need to consider matagi suji. A 4 discarded as a riichi declaration does make the 5 more dangerous, but a non-suji 5 is already very dangerous. It can make an impact when deciding whether to push or fold, though.
+"Tiles outside of early discards" are relatively safe; about as safe as regular [[suji]] (but a bit less safe).
 ==External links==
+* [https://pathofhouou.blogspot.com/2020/08/analysis-ura-suji-and-matagi-suji.html Matagi suji danger analysis] on Path of Houou
 * [https://www.mahjonggem.com/blog/2019/6/12/matagi-suji Matagi suji] on Mahjong Gem