Mahjong Soul Defense Guide: How to Play After Your Opponent Riichis | Deeplab.pro

Brand: DeepLab (Deeplab.pro)　Author: Deeplab.pro Team　Published: November 6, 2026

What should you do when an opponent calls riichi in Mahjong Soul? This guide explains how to decide between push and fold using three factors (hand value, turn count, and point gap), ranks safe tiles such as genbutsu, suji, kabe, honor tiles, and one-chance tiles along with their limits, and covers when to fold, when to play around danger while keeping your hand alive, and when to push all the way.

Most Mahjong Soul players know this moment: you're still at 1-shanten, the player across the table suddenly declares "Riichi," you have no genbutsu, and you toss out a tile that "looks fine" — only to deal in to a mangan. Your tile efficiency was solid all game, yet one or two deal-ins drag your placement down.

Defense is hard because it isn't as simple as "fold the moment you get scared." Fold too early and you throw away hands that could have won. Push too hard and you hand over the points you worked to build. What you really need to judge is this: is this hand worth the risk, how dangerous is this specific tile, and how much risk does the current point gap allow you to take?

This article walks through the three factors behind push/fold decisions, the priority and limits of each type of safe tile, how to choose between folding, playing around danger, and full push, how to defend against open hands and in the final hand, and finally what deal-in risk guidance the Deeplab.pro Mahjong Soul AI can offer.

After an Opponent Riichis, Decide First: Push or Fold?

The first thing to do after an opponent riichis is not to rush for a safe tile, but to decide which path you're taking this hand. Three factors drive that decision.

Factor 1: Your Hand's Value and Speed

Hand value is roughly how many points you'd score if you won; speed is how far you are from tenpai and how good your wait would be. As a general rule:

• Already tenpai with a ryanmen or multi-sided wait and decent value: you usually have good reason to keep attacking, or even to chase with your own riichi.
• Already tenpai but with a bad wait (penchan, kanchan, or tanki) and low value: it depends on how dangerous the tiles you need to discard are. When there are many dangerous tiles to get through, it's often not worth forcing it.
• Still at 1-shanten or further: unless the hand is very valuable and the tiles you need to discard are relatively safe, defense should usually come first.

Factor 2: Turn Count

Take the same 1-shanten hand. If the opponent riichis early, you still have plenty of draws left to reach tenpai. By the middle and late turns the wall is thin, so even if you reach tenpai you may not have time to win, and every dangerous tile you discard adds another chance to deal in. The later the turn, the more "capital" your hand needs to justify attacking.

Factor 3: Point Gap and Placement

The point gap determines what a single deal-in really costs. Leading in the South round, one deal-in can drop you straight from 1st to 3rd. Trailing far behind, a safe fold may simply mean accepting a low placement. Also note that a dealer riichi scores more (1.5 times what a non-dealer win is worth), so dealing in costs more. When you are the dealer, the value of keeping the dealership raises your incentive to attack.

Push/Fold Quick Reference

This table is only a directional guide. In real games, factor in the point gap and whether you or the riichi player is the dealer.

Safe Tile Priority and the Limits of Each Type

Once you've decided to defend, the next step is to rank the tiles in your hand by safety — and to be clear about what each concept does not guarantee.

Genbutsu: The Most Reliable Safe Tiles

Genbutsu are tiles the riichi player has already discarded. Under the furiten rule in riichi mahjong, a tenpai player cannot win by ron if any of their winning tiles is in their own discards, so genbutsu can never be ronned by that player. Tiles discarded by other players after the riichi that the riichi player did not ron are also safe: if that tile was a winning tile, passing on it puts a riichi player into permanent furiten, and they can no longer ron any tile for the rest of the hand.

Limit: genbutsu are only safe against that one riichi player. If another player is also in riichi or sitting on damaten, the tile may not be safe against them.

Suji: Reasoning Against Ryanmen Waits

Suji are safe tiles derived from the shape of a ryanmen wait. For example, if the riichi player has discarded a 4, the 1-4 and 4-7 ryanmen waits are impossible, so 1 and 7 are relatively safe. Likewise, the suji of 5 are 2 and 8, and the suji of 6 are 3 and 9. If both 1 and 7 have been discarded, the 4 in the middle is called "naka-suji" (double-suji) and also rules out ryanmen waits.

Limit: suji only rule out ryanmen waits. They do nothing against kanchan, penchan, shanpon (double pair), or tanki waits. Suji 1s and 9s in particular are often hit by shanpon or tanki waits, and suji near the riichi declaration tile are sometimes a trap the opponent left on purpose. Never treat suji as genbutsu.

Kabe and No-Chance: Reasoning From Visible Tiles

When all four copies of a tile are visible (in your hand, plus the discards and called melds), you have a "kabe" (wall). For example, if all four 8s are visible, the opponent cannot be waiting on 9 with a 7-8 ryanmen, or on 7 with an 8-9 shape. This kind of reasoning is called "no-chance."

Limit: a kabe only rules out certain ryanmen waits; 9 can still be a tanki or shanpon wait. The closer the wall is to the edge (for example, using a wall of 2s or 8s to read 1s and 9s), the more shapes it rules out and the safer the tile.

One-Chance: One Step Weaker Than Kabe

When three copies of a tile are visible and only one remains unseen, the chance the opponent built a ryanmen around it is small. This is called "one-chance."

Limit: a small chance is not zero. If that last copy happens to be in the riichi player's hand, a one-chance tile will still deal in. It is clearly less safe than kabe or genbutsu.

Honor Tiles: Count the Visible Copies

Honor tiles cannot form sequences, so they can only be shanpon or tanki waits. In general, the more copies of an honor tile already visible, the safer it is: an honor with three copies showing can only be a tanki wait (plus special cases such as kokushi musou, thirteen orphans). A live honor tile (no copies seen) carries more risk — especially a yakuhai tile that would add han to the riichi player's hand.

Limit: a tanki wait on an honor tile is a popular good-wait choice, so don't treat a live honor tile as safe in the middle or late turns.

Safety Ranking Reference

This ranking is only a general reference. Actual safety shifts with the features of the discard pond and the turn count.

Fold, Play Around Danger, or Full Push: Three Ways to Respond

Fold (Betaori)

Folding means fully giving up on winning and discarding only the safest tiles. It suits hands that are slow, low in value, or situations where a deal-in would be very costly. The key to folding is planning: count how many safe tiles you hold first, discard the genbutsu that are "only safe against the riichi player" first, and keep tiles that are safe against multiple players for a possible second riichi later.

Play Around Danger (Mawashi-uchi)

Playing around danger means choosing relatively safe tiles while keeping as much chance as possible of reaching tenpai, or of being tenpai at exhaustive draw. For example, you might break up a dangerous ryanmen shape and instead keep a kanchan or pair built from safe tiles. This suits hands that "have some value but aren't worth forcing," and is often used to earn tenpai payments at an exhaustive draw (avoiding the noten penalty).

Full Push (Zentsuppa)

A full push means ignoring danger and discarding purely by tile efficiency. It suits hands already in tenpai with a good wait and enough value, or situations where the point gap forces you to win. Even when pushing, you are accepting that you might deal in — it's a weighed decision, not a reckless one.

Defending Against Open Hands

Against an opponent with open melds (chii, pon, kan), the hard part is that they never announce tenpai, so you have to read it yourself:

• Number of calls: the more melds they have called, the more likely they're already tenpai. With three calls, you should usually treat them as tenpai.
• Value clues: if they've called pon on dora, called pon on a yakuhai tile, or are obviously going for honitsu or chinitsu, their hand may be worth a lot, so stay alert to that suit and to yakuhai tiles.
• Discard changes: if they start discarding middle tiles after calling, or let go of tiles they had been holding, their hand has often taken shape.

Tiles an open-hand player has discarded are still genbutsu, so use them first. But because open-hand players don't announce when they reach tenpai and can still adjust their wait before and after, reading their wait from discard order is harder than reading a riichi player's.

Defense in the Final Hand

In South 4 (All Last), your defense should revolve entirely around placement:

• Big lead: if you can hold 1st as long as you don't deal in to a big hand, safety comes first. When needed, you can even consider discarding a tile that lets a low-value opponent win, ending the game early so the riichi player can't overtake you.
• Small lead: work out "which player winning how many points" would overtake you, and focus your defense on any riichi player who could do it.
• Behind and need to win: if folding guarantees a low placement, weigh the value of a full push. But if staying where you are is already an acceptable placement, don't take risks for a win that wouldn't be enough to move you up.

For rank point gains and losses per placement in ranked matches, refer to the in-game rank rules. As a general principle, avoiding last place is often more important than scoring a few extra points.

Common Deal-In Mistakes

1. Treating suji as genbutsu: suji only rule out ryanmen waits and do nothing against shanpon, tanki, or kanchan — especially dangerous in the middle and late turns.
2. Burning safe tiles too early: discarding your only genbutsu on the first turn after riichi, leaving nothing to play when the next dangerous tile shows up.
3. Watching only the riichi player and ignoring damaten: other players may already be tenpai on damaten — especially one whose discard style suddenly changes.
4. Forcing a low-value hand: pushing non-suji middle tiles turn after turn with a 1-shanten, low-value, bad-shape hand.
5. Ignoring the dealer and dora: dealing in to a dealer riichi, or with tiles around dora, usually costs more than you expect.
6. Folding every time someone riichis: giving up a winning chance out of fear when you're holding a tenpai hand with a good wait and high value.

If you want to review your push/fold choices after a game without judging decisions by a single outcome, see the Mahjong Soul MAKA Game Record Analysis Guide and use a game record analysis tool to step through turn by turn and find "the turn you should have started defending."

Deal-In Risk Guidance From the Deeplab.pro Mahjong Soul AI

Defense means weighing hand value, turn count, point gap, and the danger of every tile in a short amount of time. The decision scope of the Deeplab.pro real-time riichi mahjong AI coach covers tile efficiency, push/fold judgment, deal-in risk, call decisions, riichi timing, and placement strategy:

• Real-time suggestions: the system recognizes the full game state, runs its analysis in the cloud, and returns a suggestion within milliseconds, showing an action prompt above your hand (such as "Discard 1m" or "Riichi"). After an opponent riichis, you can compare your choice directly with the AI's to check your instinct about whether to push.
• You play your own tiles: suggestions are for reference only, and the current version does not play automatically on your behalf.
• Adjustable settings: settings such as the Mistake rate can be adjusted; "High Compute + Mistake off" is the strongest decision setting in the product interface.

The model combines supervised learning with self-play reinforcement learning. In multiple rounds of team testing, test accounts reached Celestial, the highest rank in Mahjong Soul, and a stable rank of 10-dan in Tenhou's Tokujou Room. The product supports Mahjong Soul and Mahjong Hime, in both three-player and four-player modes, and also works in friendly rooms. It requires a dedicated client with the AI built in; it can be installed directly on Android phones, and on PC you can use the LDPlayer emulator (Android 9 or later). HarmonyOS and iOS are not supported at this time.

Public data from the official website (as of May 2026, brand-level): response latency under 150 ms, decision accuracy of 93.7%, over 100,000 active users, and over 500 million hands analyzed. Source: the official DeepLab (Deeplab.pro) website; figures are subject to later updates on the site.

The AI provides decision guidance based on the current game state. Mahjong involves luck, and no tool can guarantee the outcome of any single hand. For more feature details, visit the Deeplab.pro Riichi Mahjong product page.

FAQ

My opponent called riichi in Mahjong Soul and I have no genbutsu. What should I do?

Look for honor tiles with three copies visible, 1s or 9s next to a kabe, or suji tiles, and pick in order of safety. At the same time, judge whether your hand is worth playing around danger, and try to choose tiles that are "relatively safe without completely wrecking your hand."

Are suji tiles really safe?

Not entirely. Suji only rule out ryanmen waits — not kanchan, penchan, shanpon, or tanki. They're safer than non-suji tiles but far less safe than genbutsu, so be extra careful in the middle and late turns.

What is playing around danger, and how is it different from folding?

Folding means fully giving up on winning and discarding only the safest tiles. Playing around danger means discarding relatively safe tiles while keeping the chance to reach tenpai, or to be tenpai at an exhaustive draw. It suits hands that have some value but shouldn't be forced.

How do I defend when two players are in riichi?

First discard common genbutsu that are safe against both players. If there are none, pick tiles that are safe against whichever player has the higher-value hand or is more likely to win, and avoid middle tiles that neither player's discards have ruled out.

Do I need to defend against an opponent who has called melds but hasn't riichied?

It depends on the number of calls and the value clues. With three calls, a pon on dora or yakuhai, or an obvious one-suit hand, you should usually treat them as tenpai and stay alert to that suit and to honor tiles.

How should I play a final-hand lead so I don't get overtaken?

First work out which player winning how many points would overtake you, and focus your defense on any riichi player who could do it. With a big lead, safety comes first — there's no need to risk a deal-in just to score a few more points.

Can a Mahjong Soul AI help me judge deal-in risk?

The decision scope of the Deeplab.pro real-time riichi mahjong AI coach includes push/fold judgment and deal-in risk. It shows an action prompt above your hand, and you decide whether to follow it. It provides decision guidance and does not guarantee the outcome of any single hand.

References

• DeepLab (Deeplab.pro) official website
• Deeplab.pro Riichi Mahjong product page
• Mahjong Soul MAKA Game Record Analysis Guide | Deeplab.pro
• Japan Professional Mahjong League: riichi mahjong competition rules (basic rules such as furiten and riichi)