Dude, why not provide a paragraph or two, I don't need nor expect a novel. No debate, the debate is what Alan told us, without any proof, outside reference, of which you said was nominally correct. I don't expect a novel, I'd like an example of what he said being factual from an outside reference as I provided.
Well, ok. Here's what Alan said, in total:
Early Japanese codes were broken because of style. If I recall correctly, they always started off a transmission using weather or some other standard words. Just to check the communications link. Codebreakers knew what those words were and were able to work backward from that to help break the rest of the message encryption or codes.
There are a bunch of things you could pick apart in that statement if you really wanted to. Which codes (JN25 wasn't the only one they used)? Were they broken *solely* because of "style?" What does "style" even mean - the "hand" signature? The word choice? The sign off? All of these are valid questions, but the fact remains that the general statement that, "Codebreakers knew what those words were and were able to work backward from that to help break the rest of the message encryption or codes..." is a reasonable generalization, even within the context of the Urqhard quote your provided. Quoth Urqhart:
The American code breakers were able to figure out the Japanese code for “ship”. Then, by comparing the huge volume of intercepted communications, the code breakers gradually came to understand the secrets underlying JN25.
How did they figure out the code for "ship?" How did they put that word into context by using a "huge volume" of other intercepted communications? How did they find patterns in those communications that allowed the final deconstruction of the code?
Alan may be confusing that story with the Enigma story at Bletchley Park, but even if that's the case, I can argue the technicality and point out that the Japanese also used a version of Enigma and those codes were also broken at Bletchley Park
Actually your qualifications are moot, as are mine. Facts are not.
Sort of, but my "qualifications" such as they are are relevant when my "qualifications" directly apply to my knowledge of the subject, especially when we're debating a fairly generalized statement such as the one Alan made. For context, suppose someone said, "Photographers love taking pictures in Santa Fe these days because aspens are super-cool." Then someone pops in and says, "Bullshit" and posts a quote about how Colorado has killer aspens. Then you come in and say, "No, people pretty much still dig the aspens in Santa Fe too," and then I get all agitated and tell you to prove it, and further make a comment to you like, "maybe if you ever actually bothered to go to Santa Fe you'd be better qualified to offer an opinion. Maybe," not realizing that you live there and do significant photography work there and might - just might - have a clue what you're talking about.

. (And if nobody actually shoots the aspens in Santa Fe, well, then, I suck, but I love the Aspen trail up on the way to the ski area.

)
See what I'm getting at here? But I digress...
I'm not certain it's valid and the data I uncovered and provided seems to suggest he's not.
Here's the crux - what you posted doesn't actually suggest that. It describes one part of the decryption history. It doesn't claim to present the whole story, and there's plenty of room for both Urqhart's statement AND Alan's.
Now maybe you have some outside reference/data that you can provide that backs up what he said. That's all I'm asking.
If you really need me to I'll go back and dig into the subject, but I'm comfortable taking the W on the Enigma technicality
But again, after pages here, actually years of reading his posts, I find I have to fact check him and when doing so, he's kind of out in the weeds. I don't believe I'm the only one here with that experience but I'll let others speak for themselves.
No, I get it. You're presupposing that Alan is wrong and that he was speaking off the cuff without factual knowledge of what he's saying. I can't deny that happens, but in this case, I don't think it did.
How nominally correct is he?
In my opinion, his statement reads as incomplete, but accurate to the extent that some unspecified aspects of non-mathematical/non-mechnical evaluation helped break some Japanese codes before and during WWII.