{
  "schema_version": "1.0",
  "entity": {
    "id": "singapore-mahjong",
    "name": "Singapore Mahjong",
    "canonical_url": "https://wonghongwei.com/singapore-mahjong/"
  },
  "ruleset": {
    "id": "WHW-SGMJ-PRACTICE",
    "name": "WongHongWei.com practice table",
    "version": "2026.08.25",
    "implemented_by": "https://wonghongwei.com/singapore-mahjong/",
    "documented_by": "https://wonghongwei.com/singapore-mahjong-guide/"
  },
  "sources": [
    {
      "id": "whw-guide",
      "name": "WongHongWei.com Singapore Mahjong Guide",
      "url": "https://wonghongwei.com/singapore-mahjong-guide/#sec-9-pinghu",
      "kind": "first-party-documentation",
      "accessed": "2026-08-25"
    },
    {
      "id": "whw-scorer",
      "name": "WongHongWei.com Singapore Mahjong scorer",
      "url": "https://wonghongwei.com/singapore-mahjong/",
      "kind": "first-party-implementation",
      "accessed": "2026-08-25"
    },
    {
      "id": "singaporemahjong-rules",
      "name": "SingaporeMahjong.com rules",
      "url": "https://singaporemahjong.com/rules/",
      "kind": "external-ruleset",
      "accessed": "2026-08-25",
      "note": "Defines Ping Wu as All Chow without exposed Flower or Animal tiles and explicitly notes that Singapore rules vary."
    },
    {
      "id": "spgg-2024",
      "name": "Singapore Polytechnic Graduates' Guild Mahjong Rules and Regulations, January 2024",
      "url": "https://www.spgg.org.sg/web/content/114907/",
      "kind": "external-competition-ruleset",
      "accessed": "2026-08-25",
      "note": "Documents a four-double Ping Hu, its eye and wait restrictions, and a separate mixed Ping Hu treatment that may retain bonus tiles."
    }
  ],
  "rules": [
    {
      "id": "SGMJ-PINGHU-001",
      "slug": "singapore-mahjong-ping-hu",
      "name": "Ping Hu",
      "chinese_name": "平胡",
      "aliases": ["Ping Wu"],
      "status": "implemented-and-tested",
      "page": {
        "title": "Ping Hu Rules & Table Differences | Wong Hong Wei",
        "description": "Learn the exact Ping Hu rule used by this Singapore Mahjong app, why flowers, valued eyes and Kah Long matter, and where Singapore tables differ.",
        "eyebrow": "Singapore Mahjong contradiction map",
        "heading": "Ping Hu in Singapore Mahjong: the exact rule and why tables differ",
        "lede": "Ping Hu is often described as the clean all-sequence hand, but that shorthand hides the questions that cause real table disputes: which eye is allowed, whether bonus tiles break it, whether an open Chi counts, and which waits qualify."
      },
      "short_answer": "On the WongHongWei.com practice table, Ping Hu is worth 4 Tai. The hand must contain four Chows and an unvalued eye, hold no Flower, Season or Animal tiles, and pass the discard-wait test. An exposed Chi is allowed. A self-drawn win is exempt from the wait restriction.",
      "practice_table": {
        "tai": 4,
        "conditions": [
          "All four sets are Chows; there is no Pong or Kong.",
          "The eye is not a Dragon, the player's seat Wind or the prevailing Wind.",
          "The player has no Flower, Season or Animal tiles.",
          "A discard win must have had at least two possible winning tile types; self-draw is exempt.",
          "An exposed Chi is allowed when every other condition passes."
        ],
        "stacking": "Ping Hu replaces the lesser All Chow award; it does not add another 1 Tai for the same four Chows.",
        "minimum_tai": 1,
        "payout_cap_tai": 5
      },
      "variants": [
        {
          "question": "Can Flowers, Seasons or Animals remain?",
          "practice_table": "No. Any bonus tile prevents Ping Hu, although a valid all-Chow shape may still earn All Chow +1 and the bonus tile may add its own Tai.",
          "common_alternative": "Some published competition rules describe a lower-valued mixed Ping Hu that can retain bonus tiles.",
          "source_ids": ["spgg-2024", "singaporemahjong-rules"]
        },
        {
          "question": "Which eyes are valued?",
          "practice_table": "A Dragon, seat Wind or prevailing Wind eye blocks both Ping Hu and All Chow.",
          "common_alternative": "Published rules agree on blocking Dragons and relevant Winds, but a household should still state its exact valued-eye list.",
          "source_ids": ["spgg-2024", "singaporemahjong-rules"]
        },
        {
          "question": "Does the wait restriction apply to self-draw?",
          "practice_table": "No. Kah Long and other single-type wait restrictions are applied to discard wins, not self-draw.",
          "common_alternative": "The SPGG competition rules also exempt a self-drawn Ping Hu from their listed wait restrictions.",
          "source_ids": ["spgg-2024"]
        },
        {
          "question": "Can the hand contain an exposed Chi?",
          "practice_table": "Yes. Openness alone does not block Ping Hu on this practice table.",
          "common_alternative": "Some groups use a concealed-hand convention. Ask before the first deal rather than assuming.",
          "source_ids": ["whw-guide", "whw-scorer"]
        }
      ],
      "examples": [
        {
          "id": "SGMJ-PINGHU-EX-001",
          "label": "Valid clean Ping Hu",
          "public_result": "Ping Hu +4",
          "explanation": "Four Chows, an unvalued pair, no bonus tiles and a self-drawn finish.",
          "fixture": {
            "hand": ["c1", "c2", "c3", "c4", "c5", "c6", "b1", "b2", "b3", "d4", "d5", "d6", "d9", "d9"],
            "bonus": [],
            "winning_tile": "d9",
            "winning_from_discard": false
          },
          "expected": {
            "win": true,
            "tai": 4,
            "includes_item_prefix": "Ping Hu",
            "excludes_item_prefix": "All Chow"
          }
        },
        {
          "id": "SGMJ-PINGHU-EX-002",
          "label": "Valued Dragon eye",
          "public_result": "No Ping Hu and no All Chow Tai",
          "explanation": "The four Chows are complete, but White Dragons form a valued eye.",
          "fixture": {
            "hand": ["c1", "c2", "c3", "c4", "c5", "c6", "b1", "b2", "b3", "d4", "d5", "d6", "WD", "WD"],
            "bonus": [],
            "winning_tile": "WD",
            "winning_from_discard": false
          },
          "expected": {
            "win": false,
            "tai": 0,
            "excludes_item_prefix": "Ping Hu"
          }
        },
        {
          "id": "SGMJ-PINGHU-EX-003",
          "label": "Animal changes the category",
          "public_result": "All Chow +1, plus the Animal's Tai",
          "explanation": "The Cat prevents Ping Hu but does not erase the lesser All Chow shape.",
          "fixture": {
            "hand": ["c1", "c2", "c3", "c4", "c5", "c6", "b1", "b2", "b3", "d4", "d5", "d6", "d9", "d9"],
            "bonus": ["CAT"],
            "winning_tile": "d9",
            "winning_from_discard": false
          },
          "expected": {
            "win": true,
            "tai": 2,
            "includes_item_prefix": "All Chow",
            "excludes_item_prefix": "Ping Hu"
          }
        },
        {
          "id": "SGMJ-PINGHU-EX-004",
          "label": "Kah Long discard wait",
          "public_result": "No All Chow Tai; cannot Hu without another source",
          "explanation": "Only one tile type completed the hand from a discard, so this practice table removes the Chow-hand Tai.",
          "fixture": {
            "hand": ["c1", "c2", "c3", "c4", "c5", "c6", "b1", "b2", "b3", "d4", "d5", "d6", "d9", "d9"],
            "bonus": [],
            "winning_tile": "c3",
            "winning_from_discard": true
          },
          "expected": {
            "win": false,
            "tai": 0,
            "includes_item_prefix": "Kah Long",
            "excludes_item_prefix": "Ping Hu"
          }
        },
        {
          "id": "SGMJ-PINGHU-EX-005",
          "label": "Open Chi is accepted",
          "public_result": "Ping Hu +4",
          "explanation": "One Chow is exposed; the remaining concealed tiles still complete three Chows and an unvalued eye.",
          "fixture": {
            "hand": ["c4", "c5", "c6", "b1", "b2", "b3", "d4", "d5", "d6", "d9", "d9"],
            "bonus": [],
            "exposed": [
              { "type": "chow", "tiles": ["c1", "c2", "c3"] }
            ],
            "winning_tile": "d6",
            "winning_from_discard": false
          },
          "expected": {
            "win": true,
            "tai": 4,
            "includes_item_prefix": "Ping Hu"
          }
        }
      ],
      "faq": [
        {
          "question": "How many Tai is Ping Hu in Singapore Mahjong?",
          "answer": "It is 4 Tai on the WongHongWei.com practice table. Other Singapore tables may use different labels, conditions or payouts, so agree the rule before play."
        },
        {
          "question": "Does a Flower or Animal break Ping Hu?",
          "answer": "Yes on this practice table. The hand may fall back to All Chow +1 if the shape, eye and wait still qualify, while the bonus tile may add its own Tai."
        },
        {
          "question": "Can an open Chi still be Ping Hu?",
          "answer": "Yes on this practice table. An exposed Chi is allowed; a Pong or Kong is not, because every set must be a Chow."
        },
        {
          "question": "Does Kah Long block Ping Hu?",
          "answer": "A one-tile-type discard wait blocks Ping Hu and All Chow here. The restriction is not applied when the winning tile is self-drawn."
        }
      ],
      "source_ids": ["whw-guide", "whw-scorer", "singaporemahjong-rules", "spgg-2024"],
      "review": {
        "written_by": "Wong Hong Wei",
        "reviewed_by": ["Wong Hong Wei"],
        "last_reviewed": "2026-08-25",
        "method": "The public rule text and worked fixtures are checked against the final scorer exposed by the playable table's test hook."
      }
    }
  ]
}