Methodology
Bradley–Terry calculation
P(A beats B) = 1 / (1 + 10^((Elo_B − Elo_A) / 400))
- Mean 1000; Gaussian prior SD 400 Elo.
- Ties count as ½ win.
- Table intervals are 95% posterior credible intervals.
Excluded data
- Internal testers.
- Battles where either contestant failed.
- Battles where either contestant has $0 recorded account spending, including sponsored provider endpoints.
- Incomplete records.
- Battles affected by the historical subagent bug.
- With Exclude early voting: early picks and battles stopped before both contestants finished.
Bootstrap sample calculation
- Developer-cluster bootstrap; B = 1,000 replicates.
- Each replicate draws D developers uniformly with replacement from D observed developers, retaining all their battles and multiplicity.
- Refit the maximum a posteriori Bradley–Terry estimate for each replicate.
- Tied rank positions split their weight equally.
- Ridgeline smoothing: Gaussian kernel density estimates, with bandwidth h = max(2, 1.06sB−1/5) Elo; s is the replicate standard deviation.
- Ridgeline axis: from the lowest 0.5th to the highest 99.5th percentile of the ranked models' curves, rounded out to 25 Elo.
Provider selection
- OpenRouter routes each model through a model-specific provider and endpoint allowlist.
- Routing prioritizes throughput, requires support for the requested parameters, and applies per-model price caps.
Definitions
- Rank likelihood: share of bootstrap samples at each rank.
- Ridgelines: smoothed Elo distributions from bootstrap samples.
- Raw win rate: excludes ties from wins.
- Tokens per second: median per-run token rate.
- Cost / time: median or arithmetic mean per task, using recorded values from eligible battles.
- Pareto frontier: ranked models with no other ranked model having equal or higher Elo and equal or lower selected cost or time, with at least one strict improvement.
- Pareto bars: 95% Elo confidence intervals.
- Thin / thick bars: thin bar is the 95% confidence interval; thick bar is the 50% confidence interval.