What do the discards tell you?
Playing your own hand well gets you halfway. The other half is watching what everyone else is doing. Every discard is public information — face-up on the table. Reading it consistently is one of the highest-value habits in the game.
When you need to discard and aren't sure what's safe, tiles fall into three safety families per suit. A player who discarded a tile from one family probably wasn't building sequences that need the others in the same family.
If a 4 was just discarded, the 1 and 7 in that suit are relatively safer — whoever threw the 4 wasn't building chow sequences that need them.
This is a probability estimate, not a guarantee. Use it when you're short on cleaner information — never as a substitute for tracking actual discards.
For any tile you might discard, count how many copies are visible — in the discard rivers, in exposed sets, or in your own hand. Every copy you can see is a copy that can't be someone's winning tile.
Danger climbs as the wall shrinks. A tile safe on turn 6 can be lethal on turn 14 — fewer rounds remain before hands close.
Every exposed set is a signal. The more sets a player has showing, the more you can infer — and the more dangerous they are.
Commit it to memory but don't react yet. Watch what suit they're keeping vs. discarding — the pattern over the next two turns tells you more than the set itself.
Their hand shape is becoming visible. If one suit disappears from their discards, they're likely building into it. Start avoiding tiles from that suit.
Danger state. They need only one more set and a pair. Any tile you throw is far more likely to complete their hand than yours. Break up your own hand and discard safe tiles only.
Break up your own hand before you discard into a player with three exposed sets — even if it means abandoning a nearly-complete hand. This discipline separates winning players from losing ones.
The discard river tells you what a player doesn't need. These four patterns cover the most common signals.
Building a suited hand, not collecting honors.
Safe to throw back the same honors they've already discarded.
Keeping mid-tiles — likely chow-heavy hand.
Mid-tiles in their kept suits become more dangerous as they develop.
They're keeping that suit entirely.
Mixed or pure one-suit in progress. Tiles from that suit become progressively more dangerous.
Pivoting from a failed plan, or folding under pressure.
Watch the next two discards for the new direction.
Start with one signal: when someone reaches three exposures, stop throwing tiles from the suit they're building. Add the other patterns once that habit is automatic.