Hi all, thank you for checking this website !
In this article, I analyse the logs of latest Tenhou-i 右折するひつじ：Usetsu suru Hitsuji. Please also refer part 1. https://riichi-mahjong.com/2020/05/14/mahjong-strategy-analysis-of-tenhou-i-usetsu-suru-hitsuji/
Before going to the main topic, I have one thing to report.
Just demoted to 6 dan yesterday after 1304 games at Houou table… May see you at Tokujo table !
Well, there was Riichi from the player across, and you got Kanchan Tenpai of 7,700 hand. What to discard ?
If you saw my previous analsys of him, you may not be surprised (But I was !). He dis carded 5p which is Suji of 2p and 8p. This is relatively safer tile, but not 100% safe tile.
From the view point of game optimal push or fold, the winning value index of 31,000 point at T1 is 0.98. So this is easy push. Because 7,700 chasing Riichi with discarding 15% hitting tile has EV of 350, which is higher than that of Betaori: -1,700.
From this choice, we can see he highly evaluate the 1st position with 31,000 point even at T1 , and the hitting probability of Dora indicator: 5m which would be discarded if he Riichi-ed. And he may have also considered 1. 1 of 4s is already discarded, 2. he can use Dora if he keeps 5m.
This Toitsu drop also shows his risk management style on Dora Indicator.
Here he called this 9m and discarded r5m. This is probably he judged he can deal with the opponents because he was 2-3 safety tiles to each. You can see each tile of his hand is consisted of the safety tiles, and also aiming for Ittsu. How beautiful ! This is one of the ideal procedure when you got bad hand.
Here, he called east wind and didn’t go for Honitsu. I couldn’t judge when I saw this situation at first, but it will be very slow if I do and should discard White/Red Dragon here.