Mahjong Strategy: Riichi Decision 4 / Junchan Sanshoku

Hi all, thank you for checking this website. This article is on Riichi decision when you have high value hand with few completing tiles.

In modern Mahjong, yaku like Junchan/Chanta is neglected because 1. Difficult to complete in closed hand, 2. Can’t use red 5 (btw, red 5 reminds me of Nigel Mansell of Williams Renault, Formula 1 driver), 3. Easy to break when wait got Ryanmen. But sometimes it comes without calling. Riichi ?

I didn’t. Junchan Sanshoku is 5 han hand, and will be Haneman if you Riichi. If the wait is not but, it would be better to Riichi because the probability of winning won’t be less than 2/3 (8,000/12,000) usually and EV will be larger. But in this case, 2 of 8m is already discarded by the player on the right. After that there was a change in the situation.

3 of 6m was discarded back to back and 8m looks really good wait. Because 4of 6m is discarded and 9m is discarded by the player on the left and the player across in early turns. Riichi ?

I did, and soon after that I drew completing tile of the player on the right, and it was Haneman ! I thought rest 2 of 8m will be in the wall, and EV of my hand will be higher when Riichi, but I should have consider EV of this round. If I didn’t Riichi, 8m will be easily discarded by the other players and which will also decrease the probability of my dealing in.

So I should not Riichi in this situation.

I hope this will be of some help to you!

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