# What changed in BFCL's V4?

V4 rebalanced BFCL's scoring weight, not just its task list. V3 split evenly across Live single-turn calls, Non-Live single-turn calls, and Multi-Turn, 33% each, with no agentic category at all. V4 cuts Live and Non-Live to 10% each, carves out a 10% Irrelevance slice, keeps Multi-Turn at 30%, and hands the other 40% to a new Agentic category. The Gorilla team's own reason: "As single-turn tasks approach saturation, weighting now favors complex, multi-step agentic tasks."

Agentic is three graded skills none of V3 had: Web Search, where the model gets a search tool and a fetch tool for questions past its training cutoff; Memory Management, testing key-value, vector, and recursive-summary memory across a session; and Format Sensitivity, a diagnostic that reruns the same calls across 26 prompt and schema variations and finds models return higher accuracy with Python and JSON response formats than with either XML variant. [Why a benchmark's score drops on a new version](/answers/agent-benchmarks/why-do-benchmark-scores-drop-when-a-new-version-is-released) covers the general pattern; V4 is a case of it done on purpose, with the harder categories named and weighted rather than found by accident.

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Sources:
- BFCL changelog, V4 release (Gorilla / ShishirPatil, GitHub): https://github.com/ShishirPatil/gorilla/blob/main/berkeley-function-call-leaderboard/CHANGELOG.md (fetched 2026-09-18)
- BFCL V4: Format Sensitivity (Gorilla blog): https://gorilla.cs.berkeley.edu/blogs/17_bfcl_v4_prompt_variation.html (fetched 2026-09-18)

Source: https://tessary.ai/answers/bfcl/what-changed-in-bfcls-v4
More on Bfcl: https://tessary.ai/answers/bfcl
From Tessary, agent reliability for AI agents in production: https://tessary.ai