Totsugeki's Problems No. 1

[Renzo]

Hi. As someone who started mahjong in July, I managed to claw my way up to 1-dan on Janryumon. But to improve further I bought Totsugeki Touhoku's Oshiete! Kagaku suru Maajan. Of import is that Chapter 5 is a set of thirty problems. These problems are chosen to that there is no half-half answers. Totsugeki specifically analysed them and had them peer reviewed. Only the problems with unanimous answers are included. So I have decided people on this forum can benefit...assuming you don't have your own copy.

Oh, I don't have a program that lets me draw up these problems, so I'll be writing them out longhand. If you know of a program please tell me.

Notte benne: All problems are tonpuu, no red, no kuitan, placement battles.

Difficulty: 1 star.
Comment: On a flat board, we have a basic probability problem. So what to discard?
Round: East 1, 0 honba, dora

Scores: Everybody is 27,000. You are South.

East: has called pon on the West you discarded on turn 3. Discards are


South: You have discarded

Reminder: the west has been ponned.
Your hand (including the draw):


West: discards are


North: Discards are


Citation: Totsugeki Touhoku, Oshiete! Kagaku suru maajan, Yousensha (2009), page 106.

[Karen]

and go for junchan

Buy i maybe wrong.

[Iapetus]

[mrrrx]

looks fastest to me. With a dora in-hand I figure the fastest choice is the best.

My initial instinct was to drop 7m (and I probably would have with only a couple seconds to think) and go for all pairs. I had to think about it to realize 8m leaves way more open, including 7 pairs. Whoops.

[sasuraiger]

Likewise, .

[Renzo]

Totsugeki says:

We have many options for the pair, so trying to use as the top pair and going for 678 sanshoku drops the speed to much. Take riichi dora 1 and (if the mahjong gods are in our favor dream for sanankou) discard .