Chiihou

Conditions

• You must be a non-dealer (South, West, or North seat)
• You must win on your very first self-draw of the round
• No calls (chi, pon, kan) may have been made by any player before your winning draw — if any player makes a call before your first draw, chiihou is invalidated
• The hand is inherently closed since you have made no calls
• Like tenhou, chiihou does not require any other yaku — it is yakuman on its own
• This is almost entirely a matter of luck, with only the drawn tile adding a small element of chance

Strategy Tips

• Like tenhou, chiihou is overwhelmingly determined by luck. The only “strategic” element is that you need to be one tile away from winning after the initial 13-tile deal, and then draw the right tile on your first turn.
• Chiihou is invalidated if any player makes a call before your draw. This means that even if your hand was ready, another player’s pon or chi on the dealer’s first discard would cancel your chance. There is nothing you can do about this.
• The probability of chiihou is extremely low but slightly higher than tenhou, since a non-dealer needs 13 tiles plus one lucky draw, whereas the dealer needs all 14 dealt perfectly. Still, it remains one of the rarest events in the game.