The Reassessment That Did Not Travel: What the 2020 Arcade Result About Exploration Bonuses Establishes, the Six Conditions That Made It Informative, and Which of Them the Language-Model Revival Drops

Abstract

(c) 2026 Pranay Mahendrakar. Licensed under CC BY 4.0. Exploration bonuses have returned. Between 2025 and 2026 at least six frameworks added an intrinsic novelty or uncertainty term to reinforcement learning with verifiable rewards for language models, each naming a classical antecedent - prediction error, pseudo-counts, epistemic uncertainty - and each reporting gains. The classical literature those antecedents come from also contains a controlled reassessment. In work published at ICLR 2020, a study held the learning algorithm fixed, tuned every bonus, and compared against plain undirected exploration across the full Atari suite; it reported that bonuses beat the simple scheme on one celebrated game, showed no visible difference from it on the rest of the designated hard-exploration set, and never beat it on games where exploration is not the bottleneck. This paper states what that reassessment establishes and, at comparable length, what it does not; extracts the six design conditions that made it informative; and audits the language-model revival against them. Sixteen papers in the revival were checked mechanically for a citation to it, and none contains one. Four of the six conditions are met by at least one paper in the revival and a fifth in part. The condition the reassessment was built to test - an evaluation arm where exploration is not the bottleneck - is met by none of them in the form it requires, although the pattern that condition exists to detect is already visible in one revival paper's own published table. This paper reports no experiments. It names two failed direct imports that the revival itself reports and does not read as evidence about transfer, states where the analogy breaks on the substrate rather than on the evidence, and specifies the comparison a 2026 survey independently asks for without knowing it has been run once already. The literature search, drafting and citation verification for this paper were carried out with AI assistance under the author's direction. Every citation was machine-verified against the arXiv record before inclusion, and every quantitative claim was read back against the cited source's own abstract or, where a claim is drawn from a paper's body or a published table, against the located passage. The absence claims in Section 7 were produced by fetching each named paper's full text and searching it mechanically; the procedure is stated in Section 2 so that it can be repeated. The author is responsible for the final text and for all claims made in it.