- Big Four Winds: check - Declared Double Riichi: nope. Not even his turn yet. - Dealer: Unlikely, since it looks like Yu Mei-ren is the dealer with the first discard.
At minimum, he's looking at a Yakuman (worth about 24,000pts right off the bat. If there's any Dora further down the line, he'll also get some extras tacked on. If he leaves it on the table hoping to declare a Double Yakuman when his turn comes around, then that's another 2 han added to his hand.
I'd just take the instant Yakuman. Much safer.
Edit: Oops, wrong calculation.
Forgot to add Four Concealed Triplets for the four triplets of Wind tiles. And the Prevalent Wind bonus. And the Seat Wind bonus.
It can be 4x (32k points * 4 = 128k points) but your calculation is incorrect.
Big Four Winds is either Yakuman or Double Yakuman, depending on ruleset. Same for Four Concealed - Single Wait. Ruleset variations include determining yakuman are stackable or unstackable, so the hand is worth single, double, or quadruple depending on the above ruleset combination. And if you tack on the unofficial Renhou yakuman, you get 5x. (the description calls it Chiihou which is what it's called in Chinese mahjong, but means a different thing in Japanese mahjong)
Riichi and wind bonuses are standard yaku and no longer count into the hand once a yakuman is held. Otherwise, a Winds yakuman would always be double or triple just by virtue of you needing at least a triplet of an applicable wind.
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And last but not least, the artist seems Chinese so this can also straight up not be Japanese Mahjong, but a Chinese variant which means a completely different scoring system.
Ones I don't know are the girl on the left of the table, the white-haired + braid person outside behind the bench, and what appears to be a second Romani on said bench.
Ones I don't know are the girl on the left of the table, the white-haired + braid person outside behind the bench, and what appears to be a second Romani on said bench.