# Tokenizer Evaluation: Fertility, Compression Ratio, Downstream Impact ve Bilgi Teorik Ölçümler

> Source: https://sukruyusufkaya.com/learn/llm-muhendisligi/tokenizer-evaluation-fertility-compression-downstream
> Updated: 2026-08-20T02:33:39.981Z
> Category: LLM Mühendisliği
> Module: Modül 6: Tokenization Mikro-Cerrahisi
**TLDR:** Tokenizer kalitesini ölçen tüm metriklerin derin anatomisi: fertility (token/word), compression ratio (bytes/token), OOV rate, bits-per-character (BPC), perplexity'ye etki, cross-lingual fertility, downstream task impact, vocab coverage, A/B testing protokolleri, Türkçe-spesifik metrikler, maliyet 'vergi' analizi, capstone evaluation framework.