NewRiichi is sente: what the threat buys before you win
Go calls a move sente when the other player has to answer it, and a riichi is that move. Tenhou's Houou logs price what three folds cost the table and what the threat costs your own hand.
NPMahjong blog · page 2記事
Strategy archive
Deep dives into advanced tactics, tournament strategies, and pro-level insights from Japan's competitive mahjong scene.
- New
NewRiichi now or wait for a better wait? Not at 37%
The 37% rule tells you how long to look before you commit, and on a riichi wait it gives the wrong answer. Houou win rates already price every wait, so the real test is what one more draw costs.
NewJapan has lost 82% of its mahjong parlors since 1978
Police license counts show Japan's mahjong parlors peaked at 36,173 in 1978 and have fallen every year since, to 6,351 at the end of 2025.
NewM-League Nov 6: Drivens sweep table A, Phoenix sink to 8th
Akasaka Drivens won both table A games on Friday, November 6, Asami Maki in a nine-hand game with seven hands of mangan or more and Suzuki Taro from an all-last riichi, for +117.7 on the night. Ishii Kazuma, 36th of 40 in the individual table, won game 2 on table B, and Sega Sammy Phoenix lost 92.5 a night after losing 100.6.
NewWhen to call in riichi mahjong: what a chi or pon costs
In a week of Tenhou Houou logs, a non-dealer's open win averaged 3,788 points and a riichi win 6,650. A call buys speed, and it pays for that speed in riichi, ura dora, and the tiles you'd fold with.
NewHow much of M-League is luck? One site did the math
An unofficial stats site has run the numbers on every M-League game record since 2018. About 88% of the gap between players over one season is luck, and average place needs around 173 games to be half skill.
NewM-League Nov 5: Setokuma wins from third, Takizawa +73.3
Round 31 of the 2026-27 regular season: Setokuma Naoki drew a closed honitsu mangan in the all-last to win from third, his eighth top. Takizawa Kazunori posted the night's biggest score, Nikaido Aki won with back-to-back mangan, and Sega Sammy Phoenix lost 100.6 and dropped out of the top six.
NewBetting on mahjong in Japan is illegal at any rate
Japan's Penal Code makes gambling a crime at any stake, and in 1948 the Supreme Court ruled that a small cash stake is still gambling. Top prosecutor Kurokawa Hiromu's ¥100-per-1,000 mahjong game ended in a ¥200,000 fine.
NewPlaying with the lead: rich men don't pick fights
A Japanese proverb says the rich don't pick fights, because a fight can only cost them. For the player in 1st that means cheap hands, earlier folds against 2nd, dama over riichi, and counting what 2nd needs to pass you.
NewM-League Nov 3: Sakura Knights win both, lead by 322.6
Round 30 of the 2026-27 regular season: KADOKAWA Sakura Knights won both games on their table and lead the league by 322.6 points. On the other table Takeuchi Genta took his first top in 14 games, Setokuma Naoki took his seventh, and Watanabe Futoshi paid 12,000 twice.
NewDoes mahjong coaching work? Bloom's two sigma
A famous 1984 study found the average tutored student beat 98% of a regular class, an effect of two standard deviations. Later research cut that effect size by more than half, and what's left is still one of the strongest effects in education.
NewSpeed over value: a shogi proverb for All Last
In shogi's endgame, speed beats material. In All Last, points are the material and placement is the mate, which is why a 1,000-point call now beats a mangan two turns late.
Free deck何切るTwenty hands.
Twenty hands.
Pick your discard.
A free nanikiru deck from a Japanese professional mahjong player (JPMA) in Osaka. It starts with loose tiles and ends with a riichi on the table. Every answer shows the tile count behind it.
- Twenty problems, in order. Fundamentals first, then shapes, value, riichi waits and one defense spot.
- Answers on their own page. Decide first, then check. No peeking by accident.
- Printable PDF. Do one a day, or all twenty on the train.
I'll email you a link to confirm, then the deck. After that, a few short emails on how to use it, then new problems and guides about once a week. One click unsubscribes. Privacy policy