Yakuhai: keep the pair, pon the first one

You hold two red dragons in a ragged hand. On turn 4 the player across discards a third, and you let it go by, hoping to draw the last one and declare riichi. That's one of the two common ways players waste a value pair. The other is breaking the pair to keep a number shape that looked tidier.

Which honors carry a yaku, and what the pon pays

Yakuhai (value tiles) are the honor tiles that carry a yaku. A triplet of any dragon, of your seat wind, or of the round wind is 1 han, and a call doesn't remove it. When your seat wind is also the round wind, one triplet counts twice: a double wind, 2 han. The two you'll see are the dealer's East in the East round and the South seat's South in the South round. Every other wind is a guest wind, and a triplet of it gives no han. The yakuhai page has the full rules.

A pair of any of them is not a yaku. It's two thirds of one, and everything below is about getting the third tile.

An open hand usually counts 30 fu, as Fu without counting showed. At 30 fu the pon alone pays 1,000, and each dora or red five on top about doubles it.

The hand	Non-dealer	Dealer
One value-honor pon	1,000	1,500
A double wind pon, or one pon plus a dora	2,000	2,900
A pon of a dragon that is the dora	7,700	11,600

The first row is small. What it buys is speed: the hand has its yaku, so any tile that completes it wins, with no riichi needed.

A value pair plays like a good partial set

Count what finishes each block. A penchan (edge shape) like penchan waits on one tile kind, four 3s, and so does a kanchan (middle shape). You get that tile by drawing it or by a chi from the player on your left. A dragon pair waits on two tiles. But you can pon either of them from any of the three other players, and the set it makes is your yaku. Fewer tiles, more ways to get them, and the value comes free.

The pair needs a partner to work this way. If the dragons are your only pair, a pon turns your head into a set and leaves you without one. That doesn't rule the pon out, as the next section shows. It decides which block you break: keep the second pair as your head, and cut the weak partial set.

A single value honor gets the same respect. A loose (isolated) dragon and a loose guest wind can each grow only by pairing. A paired dragon can become this pon, while a guest-wind pon gives no yaku. So the guest wind usually goes first, and a loose 1 or 9 usually goes before the dragon too, as What to discard first showed. A pinfu-shaped hand is the exception: it keeps the guest wind as a head candidate and lets the dragon go (Pinfu and tanyao). Honor tile discard order has the full order, seat by seat.

Pon the first copy

When the first copy comes out, pon it. Passing feels patient: you hope to draw the third tile, keep the hand closed, and declare riichi. But the pon is a step and a yaku you can have now, and the third tile may come late or never. In Tenhou's top room (Houou), a closed dragon or round-wind pair still held at turn 8 got its third tile only 42% of the time. One with a copy already discarded did a little better, 51%, because players let go of an honor once someone has cut it (the honor order post). That data counts turns from zero, so turn 8 is your ninth discard. Even the better number is a coin flip, and the pon is certain.

The pon also frees the rest of the hand. With the yaku on the table, every later draw and call can chase speed. Yakuhai hands are the fastest open hands: with one call at turn 8, 28% are tenpai, against 25% for the mostly tanyao hands and 14% for honitsu (open hand tenpai).

The slower the hand, the more the pon matters. A ragged hand with no dora and a dragon pair has one cheap road to a win, and the pon starts it.

Let it pass when the closed hand is worth more

Sometimes the pon saves no step. When the hand already has its five blocks and the dragons are its only pair, the pon leaves you headless, so your shanten stays where it was, as When to call chi and pon showed. The pon is still right in most of those hands, because it brings a yaku. My rule of thumb is to let the first copy pass when three things hold: the hand is a 1-shanten early in the hand, every partial set is two-sided, and the closed hand has value beyond riichi that the call would throw away.

This assumes nobody is attacking yet. Against a riichi, a pon also leaves fewer tiles to fold with, which How to fold picks up later.

Back calls: chi first, pon the dragon later

A back call (atozuke, 後付け) is a chi or pon of another tile while your only yaku is a value pair you haven't completed. Tenhou and Mahjong Soul allow it, as What is a yaku? showed: a hand needs its yaku when it wins, not when it calls. Some house rules demand the yaku at your first call (atozuke in the glossary).

Three checks come before a back call:

• Keep another pair. The dragons have to become a set, so they can't be your head.
• Count the live copies. If both copies you don't hold are already in the discards, the yaku is gone.
• Know which tiles win. A back call often ends on a pair wait (shanpon) between the dragons and your other pair. Only the dragon wins. The other tile finishes the shape with no yaku, and letting it pass makes you furiten until your next turn, the same rule the yakuhai page shows for a closed hand. If that tile is already in your discards, you can't ron the dragon either.

Make the back call when the hand already has value and the call fixes its worst shape. A dora pair does two jobs here: it's the value, and it's the second pair the dragons need.

What the table reads from a dragon pon

Every call also talks. A dragon pon tells the table you have a yaku and you're moving. A pon of a dragon that is the dora shows 7,700 on its own, and one red five more makes it a mangan, so careful players treat it as one from the moment it goes down. Defending against open hands covers that seat.

Opponents hold on to a dora dragon, too. In the same Houou data, a value pair that was also the dora, still held at turn 8, got its third tile only 27% of the time, against 42% for a dragon or round-wind pair (the honor order post). So pon a dora dragon the moment one shows, and think twice before a back call that needs one.