(EDITED - see end)

I checked GoGoD and indeed his name is "Doke" and not "Douke" but the hiragana given is ど(do)う(u)け(ke), same as the katakana ドウケ from the Kiin, though I wonder why they use katakana as most Japanese names are hiragana.

Anyway, I've noticed that sometimes the long/extended vowel in Japanese is just cut off to a single letter. Like "farewell" being さようなら (sayounara) but in the English language there's no extended "yoo" sound, just "sayonara". This also happens with Honinbo Shuwa しゅ(shu)う(u)わ(wa). We just write/say Shuwa not Shuuwa. I guess I should change my thoughts of him to しゅうわ and not しゅわ...

What's interesting is that GoGoD doesn't always cut off the extended vowel. Like Fukui Masaaki has 2 "A"s which aren't reduced to 1 A. But doing that would make his name Masaki like Takemiya but they actually have totally different names.

There are actually a bunch of "inconsistencies" in writing Japanese using latin characters where the direct "translation" of the hiragana characters into latin characters does not match the "translated" (transformed?) word. The most common being hiragana は ("ha" sound) being written as "wa" (old usage that carried forward in some cases, I believe), like when used as a particle and in "konnichiwa" (こんにちは).

Anyway, surely there is an actual translate/transform system that can being followed and I'm sure GoGoD has it correct. I would put GoGoD over wikidata, Perfect Weiqi Database, and Go Ratings, whatever those are. But I would even put GoGoD before the Nihon Kiin (where do they even have a list of latin-character names for the players anyway?). It's one of GoGoD's jobs to translation Japanese into English. The record taker at the Nihon Kiin probably isn't so particular or specialized.

-- Haha, I learned something. It's "transliteration" and presumably GoGoD is using the standard "Hepburn" style. https://en.wikipedia.org/wiki/Hepburn_romanization

In which case, the hiragana for "douke" are written as "doke". But it actually depends on whether it's the same or a different "morpheme" ("A morpheme is the smallest meaningful lexical item in a language." I'm learning more things). In this case, since it's the same name its doke. The example on Wiki for actually writing "ou" is: 仔(こ) 牛(うし) – ko + ushi – koushi 'calf'. --It's two separate Kanji so it doesn't get reduced.

Edit 2: the name "Doke" is also 2 separate Kanji 道家. But it's the same "name". I guess the difference between Doke and koushi (calf) is that Doke is 1 name-word with 2 kanji and "koushi" is 2 words meaning "baby cow" in a more direct translations or "calf" in a more English translation. 子牛

... trying to learn more Japanese is one of my current hobbies.

I'm my long ramble on Doke I probably deleted it. But there is a domestic championship Japanese skater (I already forget) with the same kanji and in their English Wikipedia article (their only mention in English?), their name is given as "Doke".

Whatever the choice, consistency is best. Are most all other players in the Hepburn style transliteration? My quick review of it seemed like that's how I see Japanese written in English characters. The other style (with "dzu") was jarring.