Riichi Mahjong · Yakuman（closed only）

Chiihou (Blessing of Earth) in Riichi Mahjong: Rules and Odds

In riichi mahjong, Chiihou (blessing of earth) is a yakuman: a non-dealer's 13 starting tiles plus their first draw make a complete hand, and nobody has called chi, pon or kan before that. The dealer's version — complete on the deal — is tenhou.

The rules for Chiihou

• Non-dealers only
• The winning tile is your first draw (tsumo); ron doesn't count
• Nobody has called chi, pon or kan before your first draw; if the dealer or the player before you calls or makes a closed kan, chiihou is off
• Any complete shape works — four sets and a pair, seven pairs, thirteen orphans; no other yaku needed

How Chiihou is scored

The yaku and points below are computed live by the same scoring code the game uses.

As with tenhou, ordinary yaku don't add anything; if a hand-shape yakuman such as suuankou or kokushi musou is also there, the multiples add up.

Chiihou odds

A non-dealer's starting hand plus first draw is also 14 random tiles. We drew 14 random tiles 50,000,000 times:

• The chance they're already complete is 0.0003%, about once in 329,000 — the same as tenhou.
• Chiihou also needs no calls or kans before your turn, so the real rate is a little lower; but with three non-dealers, the chance that someone gets chiihou in a hand is roughly three times that.
• The chance of being tenpai with 14 tiles is 0.070%; then you can declare double riichi on your first discard.

Earthly hand in other mahjong styles

• Sichuan mahjong: earthly hand, straight to the cap (Sichuan mahjong Earthly Hand)
• Taiwanese mahjong: earthly hand 16 tai; Taiwan also has the "human hand", ron on the dealer's first discard, 16 tai (Taiwanese mahjong scoring)
• Hong Kong mahjong: earthly hand, straight to the limit (Hong Kong mahjong fan table)

To try your luck, open a table of free online riichi mahjong — the computers play with you and count the points for you.

FAQ

What's the difference between chiihou and tenhou?

Tenhou is the dealer complete on their 14 starting tiles; chiihou is a non-dealer complete on their first draw. Both are yakuman.

Is a ron in the first go-around chiihou?

No. Chiihou is tsumo only. A first-go-around ron is "renhou" under some rules; this site doesn't have it.

Does chiihou still count if someone called pon before my first draw?

No. Any chi, pon or kan before your first draw turns it into an ordinary tsumo.

Related yaku

Tenhou Yakuman（closed only） The dealer is complete on the deal: a yakuman of pure luck. Rules, tenhou vs chiihou, stacking yakuman, and the odds. Double Riichi 2 han（closed only） Riichi on your first discard for 2 han instead of 1: the rules, what stops it, examples and the odds of a tenpai start.