Recently, I’ve been having a rough losing streak on Tenhou, which usually comes as a result of some bad luck and some bad decisions. While it can definitely be mitigated, bad luck is something that all Mahjong players just have to learn to deal with. But bad decisions, whether caused by a theoretical mistake or an executional mistake, can be fixed with the right approach.

And so I’ve been looking through replays of previous Tenhoui to try figure out just how they were consistently able to make it to the top of the ladder. I’ve been finding a decent amount of success comparing my thoughts on positions with their decisions. Since I’m joting down a bunch of notes anyways, I figured why not make it public? Maybe they’ll be useful for someone.

So each week, I’ll be going through the replays of a different Tenhoui and looking at some key positions that either I had trouble with, or provide some insight into the overall style, goals and thought process of the player I’m analyzing. I’ll start by writing down what my instincts tell me about the situation, and then once I see the decision they make, I’ll write my interpretation of their decisions. This way, I’ll be able to deeper understand how my instincts guide my decisions and what habits come with those instincts. Then I can work towards either correcting that perspective, or if I think I’m in the right, at least I will be able to consider alternatives.

Since the analysis will be pretty in-depth, I’ll be covering one full rotation (East round or South round) per day, instead of the usual full hanchan.

The Tenhoui I’ll be examining for this week is the newest one, yoteru, who is a semi-famous Mahjong blogger/researcher. From what I’ve seen, he plays relatively textbook, with a very well-rounded style grounded in strong fundamentals, so he is easy to learn from.

Twitter: https://twitter.com/yoteru11

And if you want to follow along, I’ll also be leaving links to each replay I analyze.

Replay: http://tenhou.net/0/?log=2020050703gm-00a9-0000-bcd2f71a

East 1-0

Instinct: Cut Pei. This is a potential disarm hand, where we want to chi 7p and hold safe tiles while aiming for renchan. I currently have three blocks (99m, 89p, 発発) and would like to draw around my floats (3m, 6m, 4p) to create strong blocks to call with.

yoteru: Cut 4s, looking for honiitsu. Shapes are too weak to chi 7p right now even if we do have a few safe tiles. Honiitsu mangan chance is the main line. Our blocks are 3m+6m+99m+発発+Jihai. Drawing into any manzu helps us, and if we get lucky and draw into something like 2m+8m, suddenly we’re 3-shanten from a mangan. The bottleneck right now is drawing into a jihai pair, and we want to increase the chance that we draw into a jihai pair as much as possible, so we keep pei. Only look to make this a dismarm hand if we draw into 7p ourselves.

Takeaway: Dora-iro honiitsu is strong. Look for mangan whenever you can, especially in the East round. As dealer, don’t just settle for a 1500 point hand that isn’t much quicker than the value outs in your hand. Even if you renchan, there is no guarantee that the next hand will be any better than the current hand. Avoid slow/mid-speed 1500 point hands that require shortening your hand with calls, as that leaves the potential to be punished when you inevitably run out of safe tiles.

Instinct: Cut haku/pei. I want to keep open the possibility of chi 89p for a “quick” hand to renchan, and we still leave the manzu honiitsu route alive.

yoteru, a Tenhoui: 8p. Both 8p and 9p are dangerous to the board, and it’s already the 6th turn; our hand is no longer quick even if we do chi 89p. There is no point pushing something like a 2900 bad wait tenpai once it’s already mid-round. Instead, we want to maximize our chances at completing our mangan hand, while also keeping as many safe tiles as possible. Also, haku is shousangen/daisangen potential for Pete’s sake!

Takeaway: With open hands in the middle stages of the round, keep safe tiles while commiting to value in order to have the best chance of taking a good fight in the later stages of the round.

East 2-0

Instinct: Cut 9p. 9p looks redundant, and I want a safe tile / potential to draw into a pei pair to call with.

yoteru: Cut pei. While the 9p seems redundant, it generates a really strong shape on the 8p draw (5556789p), which can be used as 2 mentsu + 1 head. Since we already have 1 mentsu in the manzu with 123m, all we’d need is to create one more block with 8m27s. While drawing into the pei would be nice, we have 2 dora and our shapes are good enough to play menzen and aim for mangan. Calling for 3900 would be a waste of this hand.

Takeaway: Don’t automatically assume that lone 19 tiles are useless; investigate the shape a little bit more before making a decision. Aim for menzen mangan hands instead of open 3900 when you have 2+ mentsu completed or 1 mentsu + strong shapes in the early game.

East 3-1

Instinct: Discard 4s. The 47s suji is dead, we see 2233s, kamicha made a bunch of calls from souzu shapes and toimen dropped aka 5s. With all that information, 4s is unlikely to deal in. If we draw into a third dora for example, then we really want to push, and we don’t want to risk the 4s later when it’s more dangerous to simocha.

yoteru, a tenhoui: Discard 7s. Even if 4s should pass, which is hardly a guarantee, our hand is still ryanshanten and requires us to push a bunch of potentially dangerous tiles (as well as the tiles we draw) before tenpai. This is pushing into both simocha with 3 open calls and toimen with the double-east called. Commit to folding here and only think about pushing if we can safely push via some lucky chiitoi draws. 7s is safe for kamicha, and toimen hasn’t discarded tedashi so it’s basically 100% safe. Let 3rd place toimen and 4th place kamicha duke it out.

Takeaway: If your hand is ryanshanten / bad iishanten, and there’s a decent chance you’ll deal-in if you push towards tenpai, it’s probably not worth pushing. Don’t just assume you should push because you see a bunch of value in your hand.

East 4-1

Instinct: Discard East. East is safe to kamicha, and there’s a decent chance we can still progress with this hand.

yoteru: Discard 4m. Kamicha just called the hatsu and dropped a ryanmen, so they are most likely tenpai. Since we don’t see any dora and it’s relatively easy to use, either kamicha has a dora bomb that we don’t want to push into, or toimen/simocha have enough value to push into kamicha. Progressing with this hand would most likely require dropping one of 47p, as well as the dangerous tiles that we draw before we hit tenpai.

Takeaway: Don’t just concentrate on one threat; think about the threat level of the entire board. If you don’t have a fighting hand by the time other players look tenpai, then there’s no point in pushing; instead, let the other players push into each other. Fold starting with tiles that are safe against the person who is currently in tenpai, so you can hold as many globally safe tiles as possible in case one of the other players hits tenpai.

Summary

• Especially in East round, always look for potential realistic mangan outs, no matter how bad your starting hand my look. Honiitsu is usually worth looking for if you have a yakuhai pair and a bunch of jihai. Keep those mangan outs as live as possible instead of widening your ukeire for cheap, mid-speed hands.
• Don’t haphazardly try to speed up your hand at the cost of value in the mid-game. Instead, hold safe tiles and aim to push with value in the late game if you draw into the right tiles, folding if your draws do not go your way or things look too dangerous. Disarm hands do not have enough value to participate in showdowns, and are meant to avoid them by hitting tenpai/strong iishanten before the mid-game. An iishanten hand with a weak-shape that’s also short because you’ve called is not a strong disarm hand.
• Make sure to evalulate the pros/cons of keeping 19 tiles vs. jihai for your hand, instead of automatically cutting one or the other.
• Don’t push ryanshanten hands in the midgame if there’s a chance that one of the other players are in tenpai.
• When commiting to folding, start by cutting tiles that are safe for the player that looks tenpai, and hold tiles that are safe to the entire board in case another threat emerges.