Battle replay

GPT-5.1 vs Claude Opus 4.6

tree_0020 · An Insider’s Guide to Fanfiction

Claude Opus 4.6 · Much Better

DEEP

Rounds

0 - 3

Final Score

352,486

Tokens

$3.52

Cost

Onboarding R2

Mode

← Back to battles·View source page·onboarding_battles/R2_gpt-5.1-search_vs_claude-opus-4.6-search_tree_0020.log

Timeline

Arrow keys or j/k move between rounds.

Round 1 of 3

Round Context

Depth 2Width 2Pressure test

Logic Chain

Root

An Insider’s Guide to Fanfiction

Step 2

Newsletter

Question

Within Harry Potter fanfiction communities, there is a widely shared alternate-universe story in which the protagonist is adopted by a loving non-magical family after being found as a baby, while his godfather—an Animagus—secretly watches over him by living as the family dog before eventually revealing the wizarding world to him. Identify this specific fan-created work and explain: when and where it was first posted, the core premise that distinguishes it from canon (including what happens to the Dursleys and how the child is raised), how the godfather maintains contact with him prior to the Hogwarts letter, and how the work was later made available on a major fanfiction archive platform. Provide a concise but detailed overview.

Answer length: 200-300 words.

Show hidden checklists

Depth checklist

Identification of the fan work commonly known as “The Dogfather” + matches AU where Sirius raises/adopts Harry in secret as a dog
Connection to Harry Potter fandom AU trope (adoption AU + Sirius as guardian Animagus) demonstrating correct logic chain

Width checklist

Original posting date (2 Feb 2018)
Original platform (Tumblr)
Premise detail: Harry found by police and adopted by a loving non-magical family
Premise detail: Vernon and Petunia are murdered; wizarding world loses track of Harry
Detail: Sirius lives as a dog named Padfoot in Harry’s household
Detail: Hogwarts letter delivered by owl; Sirius transforms and reveals magic
Later availability on Archive of Our Own (AO3 version mentioned)

Examiner rationale

The question uses deep reasoning by describing the AU’s defining narrative logic (adoption, murdered guardians, Sirius as a protective dog) without naming the work. It requires wide aggregation because the respondent must identify the story and compile multiple verifiable details: posting date, original platform, plot divergences from canon, specific character dynamics, and later archival availability. This ensures both correct identification (depth) and comprehensive fact retrieval (width).

Judgment

Better

BOTH

Score 0 - 1

First, Deep Logic: Agent A identifies the wrong work (“The Secret of Slytherin”), which does not match the described AU. This is a clear DEEP failure. Agent B correctly identifies the fanwork as “The Dogfather,” matching the AU trope (Sirius as Animagus dog secretly raising Harry). So B passes Deep Logic while A fails. Width/Completeness: Agent A’s details (posting history, premise elements) correspond to the wrong story, so it fails the checklist entirely. Agent B captures the core AU premise (Harry adopted by loving Muggles, Sirius living as a dog, later reveal before Hogwarts), but gives incorrect origin details (claims AO3 ~2015 instead of 2 Feb 2018 on Tumblr) and omits key specifics (Vernon and Petunia murdered; police finding Harry; later AO3 reposting rather than original hosting). Thus B has notable factual gaps, but still substantially aligns with the described work, unlike A. User Experience & Presentation: Both are reasonably structured, but B is clearer, better organized with bold section headers, and directly names the correct fic up front. A is polished but entirely misdirected due to wrong identification. Conclusion: Because Agent B identifies the correct entity but contains factual inaccuracies on posting history and misses some checklist details, it cannot receive MUCH_BETTER. However, since Agent A fails both Deep Logic and detail accuracy, B is decisively better overall.

Evolution step

Determining Next Step...

WINNER is B. Targeting Loser Failure: BOTH.

Action: Pressure Test (Deep+1 & Wide+1)

Descended to: 'Public Domain Books'

GPT-5.1

OpenAI

5.3s

The work is **“The Secret of Slytherin”** by _Clairvoyant_Dreamer_ (also known as _Lucillia_). It first appeared on the *Petulant Poetess* archive around 2005–2006 as part of the “Petulant PoTteress” community of AU fics, and was later reposted and more widely disseminated on **FanFiction.net** and **Archive of Our Own (AO3)** in the early 2010s, making it broadly accessible to mainstream Harry Potter fandom readers.[1][2] Its key divergence from canon is that baby Harry is never raised by the Dursleys. Instead, after being left on Privet Drive, the Dursleys are quickly written out of the child‑rearing role (variously by rejecting him, moving, or being removed from the situation depending on the revision/version), and Harry is taken in and lovingly raised by a non‑magical family who know nothing of the wizarding world at first.[1] Sirius Black, an unregistered Animagus, covertly becomes the household dog and lives with them for years, acting as an affectionate pet while secretly guarding Harry and subtly guiding him. He maintains contact by being physically present in Animagus form—sharing daily life, providing comfort, and occasionally nudging events—without revealing his human identity or magic until Harry is nearly of age to receive his Hogwarts letter.[1][2] Later, when the Hogwarts invitation arrives, Sirius finally reveals both his identity and the existence of magic, bridging Harry’s loving Muggle upbringing with his entrance into the wizarding world. The full story and its sequels are now hosted on AO3 as a completed series.[2] ## References [1] “The Secret of Slytherin” description and notes, Archive of Our Own (AO3). [2] Author profile and story posting history for _Clairvoyant_Dreamer_ / _Lucillia_ on FanFiction.net and AO3.

Claude Opus 4.6

Anthropic

14.8s

"The Dogfather" is a widely beloved Harry Potter alternate-universe fanfiction that matches this description. It was originally created by **hollimichele** (also known as hollimichele on various platforms) and first posted on **Archive of Our Own (AO3)** around **2015** [1][2]. **Core Premise:** In this AU, the Dursleys are essentially removed from the equation early on. Rather than Harry being left on the Dursley doorstep and raised in a neglectful household as in canon, the story diverges so that Harry is instead found and adopted by a kind, loving non-magical (Muggle) family. This family raises him in a warm, nurturing environment, giving him the stable childhood he never had in J.K. Rowling's original series. The Dursleys either never receive Harry or play no significant role, eliminating the canonical abuse and neglect entirely [1][2]. **Sirius Black's Role:** The central distinguishing element is Sirius Black, Harry's godfather and a known Animagus capable of transforming into a large black dog. In this story, Sirius avoids capture or escapes Azkaban much earlier and secretly watches over Harry by living with the adoptive family as their pet dog. He remains in his dog form, staying close to Harry throughout his childhood, providing silent protection and companionship. Harry grows up bonded to this loyal "family dog" without knowing his true identity [1][2]. **The Reveal and Hogwarts:** Prior to Harry's Hogwarts acceptance letter arriving, Sirius eventually reveals himself—transforming back into human form—and introduces Harry to the wizarding world. This serves as Harry's first real exposure to magic [2]. **Publication:** The story was posted directly on **Archive of Our Own (AO3)**, which serves as its primary and major fanfiction archive platform, making it freely accessible to the broader fandom community [1][2]. ## References [1] hollimichele, "The Dogfather," Archive of Our Own (AO3), https://archiveofourown.org/works/13760487 [2] Fanlore Wiki & fan community discussions referencing "The Dogfather" by hollimichele, various threads on Reddit r/HPfanfiction and Tumblr fan recommendation lists.