The fanfic is based on an incident somewhere around chapter 330-340. Shikamaru gets little screentime, though, so you could probably just google through http://en.wikipedia.org/wiki/List_of_Naruto_chapters_%28Part_II%29 and http://en.wikipedia.org/wiki/List_of_Naruto_chapters_%28Part_I%29 for 'Shikamaru' and read just those chapters, maybe.
(Not that I'd recommend such a procedure. The worse part of Naruto is the fandom and anime. The manga itself is a pretty decent shonen manga.)
Presenting: Shikamaru vs. the Logical Fallacies, a rationalist fanfic set in the Naruto universe and starring a realistically rational Shikamaru. The writer is a friend of mine going under the alias FanFicBias, and I am an editor along with the author.
We welcome reviews on FanFiction.Net and both reviews and discussion (naturally) are welcome here. We are looking to improve our work, so please be as honest and as harsh in constructive criticism as you like. Praise, however, is also always welcome!
This story does contain SPOILERS for the Naruto series. Readers who are unfamiliar with Naruto may have a hard time understanding what's going on, but it would still be interesting to hear from non-Naruto fans, since perhaps we can ameliorate this issue with the aid of constructive criticism.
We do strive to follow the First Law of Fanfiction and the Rule of Rationalist Fanfiction, so please call us on it if we fail to do so.
http://www.fanfiction.net/s/6781426/1/Shikamaru_versus_the_Rational_Fallacies
Note: Thanks to all reviewers and participants in this discussion! We're trying hard to make Part 2 even better.