When Does Combining Language Models Help? A Co-Failure Ceiling on Routing, Voting, and Mixture-of-Agents Across 67 Frontier Models
Multi-model LLM systems such as routing, voting, cascades, fusion, and mixture-of-agents are used to beat single-model accuracy. We show that their gain is capped by a quantity the field rarely reports. For any policy whose output is one member model answer, accuracy cannot exceed one minus beta, where beta is the rate at which every model is wrong on the same query. In contrast, the usual diagnostic, average pairwise error correlation rho, cannot identify beta: error laws with identical marginals and pairwise correlations can have different all-wrong rates. A Clopper-Pearson bound on beta giv
Lineage graph
Paper → model → repo connections mined from source citations (Tier-1 exact match).
Why these links exist
Every edge carries a method, confidence, and the source snippet that justified it — so bad links are debuggable.
- FuzzySimilar title/name (fuzzy) · 87%NirDiamant/GenAI_Agents →
“Fuzzy title match (0.94): “When Does Combining Language Models Help? A Co-Failure Ceili” ≈ “NirDiamant/GenAI_Agents””
- FuzzySimilar title/name (fuzzy) · 84%Unity-Technologies/ml-agents →
“Fuzzy title match (0.92): “When Does Combining Language Models Help? A Co-Failure Ceili” ≈ “Unity-Technologies/ml-agents””
- FuzzySimilar title/name (fuzzy) · 59%datawhalechina/hello-agents →
“Fuzzy title match (0.73): “When Does Combining Language Models Help? A Co-Failure Ceili” ≈ “datawhalechina/hello-agents””
- FuzzySimilar title/name (fuzzy) · 59%TauricResearch/TradingAgents →
“Fuzzy title match (0.73): “When Does Combining Language Models Help? A Co-Failure Ceili” ≈ “TauricResearch/TradingAgents””
- FuzzySimilar title/name (fuzzy) · 59%jnMetaCode/agency-agents-zh →
“Fuzzy title match (0.73): “When Does Combining Language Models Help? A Co-Failure Ceili” ≈ “jnMetaCode/agency-agents-zh””
- FuzzySimilar title/name (fuzzy) · 59%Eigenwise/atomic-agents →
“Fuzzy title match (0.73): “When Does Combining Language Models Help? A Co-Failure Ceili” ≈ “Eigenwise/atomic-agents””