Category-a-Day 4, Section 8: Terminals

We know that honor tiles are more difficult to collect in sets because you can't create a sequence (chow). Similarly, terminal tiles (1's and 9's) are more difficult to use, even in sequences. Consider that a 5 can be used in three different sequences: 345, 456, and 567. A 2 (or 8) can only be in two: 123, or 234. A 1 or 9 can only be in one sequence. Getting a hand where every set has a terminal tile is quite a feat. Here are the patterns and scores:

8.0 Terminals

8.1.1  Mixed Lesser Terminals        :  40

8.1.2  Pure Lesser Terminals        :  50

8.1.3  Mixed Greater Terminals      : 100

8.1.4  Pure Greater Terminals       : 400

8.1.1 Mixed Lesser Terminals

On my score cards, I call this "Terminal or Honor in Each Set." In Mahjong Competition Rules and other styles, it is called "Outside Hand," and in Riichi, it is called Chantaiyao (全帯么) or Chanta (チャンタ / 全帯). This means all four sets and your pair have a 1, a 9, or an honor tile. In my experience, this pattern is harder to achieve than the 40 points awarded would suggest, even though statistics show it has about the same difficulty as one suit and honors, another 40 point pattern. Riichi strategy guides generally recommend avoiding this as a target, although that could be because terminals are often discarded early in riichi games.

8.1.2 Pure Lesser Terminals

Also called "Terminal in Each Set" (by me) or Honroutou (混老頭) in riichi. The pattern is not awarded in MCR (but you do get one point for No Honors). This means that each of your sets and your pair must have a 1 or 9 tile. No honor tiles are allowed.

8.1.3 Mixed Greater Terminals

MCR calls this "All Terminals or Honors" (as do I) and riichi calls this Junchan tayao (純全帯么) or Junchan (純チャン). It means that your hand contains nothing but 1's, 9's, and honor tiles. No easy chows for you! There are 13 tiles you could make triplets of, and you have 4 plus a pair. Nice job. Have 100 points, plus 30 for Four Triplets, and points for any honor sets you may have, maybe One Suit and Honors too.

8.1.4 Pure Greater Terminals

Also called "All Terminals" or Chinroutou (清老頭). Now you've done it. There are six different terminal tiles, and you have triplets of four of them, and a pair of the fifth. That's outrageously rare. It turns out to be exactly as rare as having pungs of all four winds with a pair of anything else. It also scores the same 400 points. This is a listed limit hand, so you can score only one pattern. So sad.