by Amit Shekhar · 19 August 2026
The Lost in the Middle Problem in LLMs
The Lost in the Middle problem in LLMs, the strange behaviour where a model reads a very long text, uses the beginning and the end very well, and quietly ignores whatever is sitting in the middle. We will also see what a context window really means, how the accuracy forms a U-shaped curve, why the middle gets forgotten, how this silently breaks RAG systems and long conversations, how we can test our own model for it, and what we can do to fix it.
Before you read, guessWhat phenomenon describes an LLM prioritizing information at the start and end of a long input while neglecting the middle?
Ten seconds, a guess, then read — a wrong guess still makes the answer stick.
What this article covers
- What is a context window
- What is the Lost in the Middle problem
- Let's understand it with an example
- The U-shaped curve
- Why does this happen
- Where this hurts us in real life
- How to test for the Lost in the Middle problem
- How to solve the Lost in the Middle problem
- Key points to remember
The article lives on outcomeschool.com. Read it there, then come back: the tutor in the margin has read it and will answer questions, and the questions below check what stayed.