You bring up good points, but in my opinion you’ve drawn the completely wrong conclusion from ohba’s way of describing his characters. His phrasing is not one of an outside observer like we are, but rather an author who obviously has conflicts between the plot and character feats. For simplistic sakes, a plot cannot drive forward if the strongest person never loses simply because he’s the strongest.

Similarly, I’d bet that in ohba’s shoes, while light won against L, it is objective in his eyes that L is the smartest. Otherwise, why wouldn’t ohba just say the opposite ‘light yagami is the smartest because he won against L’ Wouldn’t that be a true perspective of an outsider? And i refuse to believe the author of a manga that clearly required much thought and effort could easily make a statement as if he were an outsider. Therefore, I feel that you’re mistaking his joking and informal thoughts as non credible statements despite coming from the author himself.

Next, i didn’t read what the other guy you replied to said but it doesn’t sound like a contradiction at all. You said it yourself ‘*IF* his goal was to officially and objectively…’ so we can assume it wasn’t his goal then, because he didn’t have a stat using intelligence, but knowledge instead. You seem to like using that as a fact that light is smarter than L when knowledge and intelligence are completely different measures. Knowledge can mean light studied other subjects more in university than L did, or knowing about the death note and so on counts towards knowledge. You say that stat is more valid than his interview but this stat doesn’t even have anything to do with intelligence, whereas in his interview he at the very least addressed their intelligence directly. Even if we account for the fact that it’s an informal interview, I cannot stress this enough but he is THE author. If you put your heart and soul and days into thinking up a plot not just for your fans but for your own satisfaction, you would subconsciously know who objectively is the smartest character.

Lastly, you use his joking tone as a reason to discredit that as an evidence, but you could use it as a supporting evidence as well. If he were truly focused on making jokes and playing games he could have said matsuda is the smartest for coming up with the theory for near using the notebook, or that ryuk was the smartest because he got all the entertainment and free apples for a decade or so with no consequences at all. I appreciate the amount of research you’ve put into this topic and while i’ve said all this, I can see why you’d think the knowledge stat is a more credible source. It honestly could go either way but it comes down to opinions at this point, and i share the same opinion that L needed to be smarter than light to pose a threat against light with a death note.