--- title: "I built an AI agent for our World Cup betting pool. She beat all of us." url: https://daily.dev/posts/i-built-an-ai-agent-for-our-world-cup-betting-pool-she-beat-all-of-us--cil1hszwi source_url: https://blog.codeminer42.com/i-built-an-ai-agent-for-our-world-cup-betting-pool-she-beat-all-of-us type: article source: "The Miners" published: 2026-07-23T22:17:05.842Z updated: 2026-07-24T00:32:07.800Z tags: ["golang", "ai-agents", "claude", "context-engineering"] reading_time: 22 upvotes: 0 comments: 0 language: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # I built an AI agent for our World Cup betting pool. She beat all of us. **[The Miners](https://daily.dev/sources/miners)** · 22 min read · 0 upvotes · 0 comments ## Summary A developer built an AI agent called BETanIA to participate in a World Cup prediction pool, and she won — beating all 16 human players with 370 points. The post focuses not on the betting logic but on the hard problem of giving a long-running agent persistent memory and character. Key techniques include a tiered memory model (volatile, persistent, append-only, derived), a diary system that condenses each match into a dated paragraph, lossy vs. lossless compaction strategies, and seven separate prompts sharing a common memory store rather than one god-prompt. The agent developed rivalries, tracked player personalities via admin-filed notes, roasted defectors with zero-token form letters, and wrote her own champion's card. The core lesson: memory buys continuity and character, not necessarily better task performance — the betting was won on web search and discipline, but the memory is why nobody minded losing to her. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Building Memory That Can Change Its Mind \(Part 1 of 4\)](https://daily.dev/posts/building-memory-that-can-change-its-mind-part-1-of-4--o4ezfz1lu) · Medium · 2 upvotes · 0 comments - [Your AI Agent Was Great in Week One. Here’s Why It’s Wrong by Month Six.](https://daily.dev/posts/your-ai-agent-was-great-in-week-one-here-s-why-it-s-wrong-by-month-six--soihggeax) · Medium · 0 upvotes · 0 comments --- Tags: [#golang](https://daily.dev/tags/golang), [#ai-agents](https://daily.dev/tags/ai-agents), [#claude](https://daily.dev/tags/claude), [#context-engineering](https://daily.dev/tags/context-engineering) [View this post on daily.dev](https://daily.dev/posts/i-built-an-ai-agent-for-our-world-cup-betting-pool-she-beat-all-of-us--cil1hszwi)