What is Belady's Algorithm?

Belady's Algorithm is a mental model used for better thinking and decision-making.

How do you apply Belady's Algorithm?

To apply Belady's Algorithm, identify situations where this framework is relevant, then use it as a lens to evaluate your options and decisions. The model is most useful when combined with other complementary mental models.

What category does Belady's Algorithm fall under?

Belady's Algorithm falls under the Computer Science & Algorithms category of mental models. Other models in this category can be found on the Computer Science & Algorithms hub page.

Why is Belady's Algorithm important?

Belady's Algorithm is important because it provides a structured way to think about problems that would otherwise be approached with intuition alone. Understanding this model helps you avoid common reasoning errors and make better decisions.

Where does Belady's Algorithm come from?

Belady's Algorithm is discussed in the tradition of Belady.

Computer Science & Algorithms

Belady's Algorithm

Model #0661Category: Computer Science & AlgorithmsSource: BeladyDepth to apply:

4 min read

Contents

1. Core Idea
2. How to See It
3. How to Use It
4. Founders & Leaders
5. Connected Models
6. One Key Quote
7. Summary & Further Reading

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Section 1

Core Idea

Belady's algorithm (MIN or OPT) is the optimal offline page-replacement policy for a cache: evict the page that will be used farthest in the future. It minimizes cache misses when the full request sequence is known in advance. In practice it is unrealizable — you don't know the future — but it defines the best possible performance and is the benchmark for heuristic policies like LRU.