---
title: "Bradley Efron"
type: "entity"
entity_kind: "person"
status: "hub"
canonical_name: "Bradley Efron"
aliases: []
first_seen: "2026-07-11T00:00:00.000Z"
writer_model: "claude-sonnet-5"
connects_to: ["James-Stein estimator","bootstrap method","shrinkage estimation","Efron-Thisted Shakespeare estimator","empirical Bayes"]
seek_code_commit: "649b1a4"
---


Statistician known for the bootstrap resampling method and for popularizing
the James-Stein shrinkage estimator through a concrete, computable
batting-average example. He recurs across this vault's estimation cluster:
his and Trevor Hastie's textbook *Computer Age Statistical Inference*
supplies the vault's baseball-shrinkage figures; his method with Ronald
Thisted (Efron–Thisted) estimated how many words Shakespeare knew but never
wrote, using the same singleton/hapax statistics the unseen-species cluster
is built on; and this session found his percentile bootstrap named directly
inside Anne Chao's 1984 paper as the method she uses to build confidence
intervals around her richness estimate — a third, independent context for
the same recurring figure.

## References
- [[claim-efron-baseball-shrinkage-halved-batting-average-prediction-error]]
- [[claim-singletons-are-the-diagnostic-of-the-unseen]] (Efron–Thisted mention)
- [[claim-chao-1984-estimator-extends-harris-1959-occupancy-bound]] (bootstrap mention, this session)
- Captures: 2026-07-11 (baseball shrinkage); 2026-08-07 (hub built)