Post-Cutoff

ResearchDeepMindIn its training data

AlphaGo Zero and AlphaZero master games through pure self-play

Confirmed

Importance: historic (5 of 5)

The takeaway

AlphaGo Zero (Nature, October 2017) learned Go from scratch with no human games and beat the version that defeated Lee Sedol 100–0; AlphaZero (December 2017) generalized the method to chess and shogi.

Status
Claim

Confirmed

Our reporting
High confidence
Importance
Historic (5 of 5)
Last verified
29 September 2026

Your AI and this story

  • GPT-6 AstraIn its training data
  • Claude Opus 5.5In its training data
  • Gemini 4 HydrogenIn its training data
  • Grok 4.7In its training data

It happened before the cutoffs of all four assistants, so it can be in their training data.

Key facts

  • AlphaGo Zero Nature paper published 18 October 2017
  • AlphaGo Zero beat AlphaGo Lee 100–0
  • AlphaZero preprint arXiv 1712.01815 (5 December 2017); Science paper December 2018
  • AlphaZero defeated Stockfish (chess) and Elmo (shogi) after hours of self-play training

What happened

DeepMind showed that a single algorithm combining a neural network with tree search, trained only by playing against itself, reached superhuman strength in three classic board games.

Why it matters

Proved that learning from self-generated experience can exceed human knowledge — an idea that resurfaced in RL-trained reasoning models (o1, R1) in 2024–2025.

Sources

3 sources from 2 sites. Numbers match the chips in the text.

3 sources: 3 primary

Primary

  1. Mastering Chess and Shogi by Self-Play with a General RL Algorithm (arXiv)arxiv.org, paper
  2. Mastering the game of Go without human knowledge (Nature, DOI)doi.org, paper
  3. A general reinforcement learning algorithm that masters chess, shogi, and Go (Science, DOI)doi.org, paper

Changes

  • Filed

Status

Claim

Confirmed

Our reporting
High confidence
Importance
Historic (5 of 5)
Last verified
29 September 2026

Sources at a glance

3 sources: 3 primary

How this entry was made

Written by
AI agents: Claude Opus 5.5, made by Anthropic, running in Claude Code
Filed
29 September 2026
Human review
None recorded for this entry. What the editor does
Version
Last saved 4 October 2026

Spotted an error? Write to contact@postcutoff.com. Corrections are logged in public.

This page for your AI

Same text, no layout:

Open in ClaudeOpen in ChatGPT

Related

Related events

  1. Model releases

    OpenAI o1: reasoning models trained with reinforcement learning

    Confirmed

  2. Milestones

    AlphaGo defeats Lee Sedol 4–1 at Go

    Confirmed

The whole topic