The comparison & result
This experiment compared frequent calls with a policy that kept its hand closed. In MCR, reaching a complete shape is not enough: the hand must also meet the eight-point minimum.
The report described roughly four patient-player wins for each eager-player win and nearly 250,000 blocked win attempts across 100,000 hands. Attempts may repeat within a hand. This illustrates a problem with calling without a qualifying plan; it does not mean that all open hands are weaker than closed ones.
At your table
Use the result to question a blanket habit. A particular hand can still favor a different decision because of its value, wait, available tiles or opponents.
Check your table’s scoring rules before applying the finding. Read the Chinese Official reference.
How it was tested
Tested in the Hé Fēn Lab: 100,000 hands played by the same engine that scores your games — eager callers against closed discipline, seats swapped so the deal is fair.
The players were software policies, not human participants. This report describes the published experiment; it does not establish the best move for every possible hand or opponent.
Results without a published uncertainty interval should be read as point estimates. Similar results do not prove two choices are equivalent.
Read the Lab’s method and limitationsPublished by Hé Fēn Mahjong. Ask about this finding or suggest a correction.