The Year of Glad opening (Hal's admissions interview) was written in early 1994; the novel originally opened with the professional-conversationalist scene.
This is material that was added after the early draft: absent from the 1993 manuscript, present in the published novel.
In the manuscript. The 1993 manuscript begins with the "professional conversationalist" scene; an early two-page draft of it ("What Are You Exactly") has Hal named "David." The YG frame does not exist.
In the published book. Scenes 1, 3 (pp. 3–17); displaced opener = scene 5 (pp. 27–31)
Evidence. Independently corroborated. The June-1994 "Typescript Draft" is the tightest documented date for the opening's first appearance — consistent with, and bounding, Max's "written early 1994" (composition precedes the June-1994 submission; the delivery is the terminus ante quem). Documented by Steven Moore's first-draft collation (original opening); D.T. Max's biography of Wallace (the "What Are You Exactly" draft); D.T. Max's biography of Wallace (YG written early 1994, replacing an opener that "stood at the book's opening for so long"); Paul Debraski's survey of the draft record; den Dulk's genetic-criticism study (peer-reviewed genetic account from the WP containers: the opening "appeared relatively late in the development of the novel, namely in the “Typescript Draft” submitted in June 1994", and "no previous drafts of the opening section are available" in the archive); Riles's firsthand archive account (firsthand HRC draft sighting: the "First Two Sections" typescript "does not start in Tucson in the Year of Glad" — the professional-conversationalist scene starts it); [hering-ff Ch.1] (the firsthand ORIGIN of the den Dulk credit, now held: "In the first iteration of the 'professional conversationalist' scene, which appears to date from 1986 and has the title 'What are you exactly – unadorned autobio – automabiography', Hal is called David. The scene is set in 1974 and 'David' is 13: Wallace would have been 12 (Box 15.6)" — supplies the container locator Box 15.6 and shows the 13-vs-12 arithmetic traces to Hering himself.
Bears on. This difference bears on the following open questions: what broke Hal if not (only) DMZ; damage vs. emergence; did Hal ingest DMZ, and by what route (dosed / endogenous / self / none); what happens between p. 981 and p. 3 (the Annulation-Text).
Further notes. Max: the new frame deliberately multiplied the explanations for Hal's state (DMZ / marijuana detox / having seen the Entertainment) — "Hints for all three of these plot twists are in the text," and Wallace "was never going to let the reader settle on one." The novel's single most theory-generative structure is a late addition. On the displaced opener's germ: den Dulk, crediting Hering, dates the autobiographical "David" draft to 1986 and carries its full working title — "What are you exactly – unadorned autobio – automabiography" — set April 1, 1974, David "13 years old" den Dulk's genetic-criticism study. The germ layer is thus double-attested (Hering-via-den-Dulk + the riles sighting), converging on the same April-1-1974 dating — and the April-1 date persisted into the published scene's in-world date. The editorial pressure that produced the frame is also now dated and quoted: Pietsch's June-1993 letter (LB 3.2) asked for significant cuts, saw Hal as the "emotional core of the novel" and hoped "to see lots more of Hal in extremis"; Moore, advising on the then-opening conversationalist scene, wrote "this is wild and funny, but rather too much so" and warned it would give the reader the "wrong idea of what kind of novel this is going to" be — den Dulk reads the admission-interview opening as Wallace's combination of both notes den Dulk's genetic-criticism study.