San Ankou

Conditions

• The hand must contain three triplets (or quads) that were all formed without calling pon; they must be concealed (drawn naturally)
• The fourth meld can be anything (open or closed, sequence or triplet)
• The pair can be completed by any means
• If you win by ron on a tile that completes your third triplet, that triplet is considered open, so only two would be concealed; you need to win by tsumo in that case or have the ron tile complete a different part of the hand
• Worth 2 han regardless of whether the overall hand is open or closed

Strategy Tips

• San ankou is often completed unintentionally when you draw well. If you find yourself with two concealed triplets, be aware that completing a third by tsumo would give you this yaku.
• Pay close attention to how you win. If your tenpai has a shanpon (dual pair) wait, winning by ron means the called triplet counts as open. Winning by tsumo ensures all three triplets remain concealed.
• San ankou can combine with toitoi for a strong hand. If you already have three concealed triplets and a fourth open triplet, you have both san ankou and toitoi for at least 4 han.