<aside class="article-notice"><b>Rewritten 2026-09-04.</b> An earlier version of this article used Japanese reading terms (suji, kabe, genbutsu). American mahjong shares the four-of-each-tile base with the Japanese game, but it has <i>no chows</i> (no runs) and adds jokers, so the Japanese theory does not transfer cleanly. This version works directly from American discard piles and the 2026 NMJL card.</aside>
<h2>What "reading discards" means in American mahjong</h2>
The four tiles a player discards, in the order they discard them, are a quiet conversation about what they have already, what they have given up on, and what they are still waiting to draw. American mahjong is friendlier to readers than the Japanese game because the card (the published hand list you play from) tells everyone roughly what is possible.
Four signals actually transfer. Three others (<i>suji, kabe, genbutsu</i>) are tempting (they also lean on the fact that there are four of each tile) but they do not transfer cleanly. We explain why at the end.
<h2>The four reads that work</h2>
<h3>1. The empty family (the strongest read)</h3>
When all four of one tile are visible (anywhere on the table) that family is dead. No one can be waiting on a tile they have already seen four of. This is the American form of the famous "kabe" read.
Two practical examples:
<ul> <li>If the discard pile contains four 7-dots and a player is waiting on 7-dots, they are not waiting there.</li> <li>If three 4-dots are visible and the fourth is in someone's exposure, no one can win on the missing 4-dot.</li> </ul>
The American twist: a joker can be substituted for any tile in a three-or-more group. So seeing four of a tile means all four real tiles are accounted for — but jokers can still complete that family. If the card requires jokers in a given hand and three of four real tiles have been seen, a joker may still be live. Trust the read for groups that do not take jokers (most Concealed hands, and the pair in any 2026 line).
<h3>2. Three visible, the missing is unsafe</h3>
When three of a tile are visible (in discards or exposures), the missing fourth is the most dangerous tile in that family. Two of the remaining three are likely someone's pair; one is part of someone else's run. If the card has any hand that uses this family, treat the fourth as live.
The Japanese read in this case (suji) is to look at the surrounding tile numbers. American mahjong has no chows, so this read does not transfer. The fourth tile is unsafe regardless of what number it is.
<h3>3. The tile the player discarded themselves</h3>
This is genbutsu, and it is the only Japanese read that transfers directly. If a player threw a tile, they cannot be waiting on it. So the safest discard in the late game against that player is one of their own discards.
Exception: a joker has been discarded. Any joker thrown is permanently dead and cannot be used by anyone. Jokers are the only tile where throwing it makes the tile completely unplayable.
<h3>4. The exposure locks the family</h3>
If a player has shown a pung of 5-bams, the remaining two 5-bams are usable by everyone else (one more pung is possible, or two pairs, depending on the card). But the exposed player is committed to 5-bams, and to whichever row on the card uses them. Read the card against what is exposed.
<h2>What the three Japanese reads become when you remove the chows</h2>
<i>Suji (筋):</i> "if 4 was discarded earlier, 1 and 7 are safer." This is a chow read. American mahjong has no chows. Discard 1 may be live for any reason; the only read is "count how many of each tile are visible," and suji adds nothing to that count.
<i>Kabe (壁):</i> "if all four 5s are visible, no one can be waiting on a run involving 5." Same read as the empty-family read we already have. Kabe is a special case of "four visible = family dead."
<i>Genbutsu (現物):</i> "if a player discarded it, they can't be waiting." Same read, transfers directly.
The Japanese theory reduces to two reads (kabe + genbutsu) when you remove chows. American mahjong has its own additions (exposures, joker stealer), and the four reads above are what you actually have.
<h2>The joker complication</h2>
Jokers substitute for tiles in three-or-more groups, and they can be exchanged by anyone holding the matching real tile. When you see three of a tile and a joker exposed, you cannot conclude the family is locked. Someone with the real fourth tile may still be in the hand.
For your reads: when the card does not allow jokers in the hand you are worried about (a hand marked C, Concealed, often takes no jokers), the read still holds. When the card allows jokers, discount the joker in your visible count.
<h2>What to do with the read</h2>
The read is information, not a decision. Your job is to compare the read against the hands on the card that any player at the table might be playing for. A 6-dot may be live for the row you are playing, and live for three other rows someone else is playing for. Sometimes the read confirms what you already knew. Sometimes it changes your discard.
Two habits make the read work. First, count visible tiles as you go: discards plus exposures plus your own rack plus known discards of others. Second, before you discard, ask yourself: is there a row on the card, for any player at the table, that this tile completes? If yes, throw something else. If no, throw it.
<h2>Further reading</h2>
The full defensive reading guide is on the Defense page, and the discard analysis step-by-step is on the Reading the table page. The 2026 NMJL card is the final authority on what any hand is allowed to look like.
<hr><small>The prior Japanese-terms version of this article is retained in our archive for reference only. New readers should use this rewrite.</small>