llmrun

Methodology · Reference scale 2026-Q4

How the llmrun Composite Score is built

The llmrun Composite Score ranks a language model on an open-ended scale: 100 marks the typical performance of models in our reference field, based on data from the public leaderboards we monitor. Here you'll find how we calculate it and its known limits.

Reference benchmarks
40
Sources in the score
4
Frozen scale
2026-Q4
Held-out error (RMSE)
0.093

01

Overview

llmrun doesn't run benchmarks. Scores are calculated using data already published by independent leaderboards, with every source credited.

  1. 1

    Public leaderboards

    Results published by 4 independent sources.

  2. 2

    Normalize

    Every result gets rescaled to a range of 0 through 1, moving from the benchmark's random-guess floor up to its maximum limit.

  3. 3

    IRT fit

    Each model gets one ability θ, alongside a difficulty b and a discrimination a for every benchmark.

  4. 4

    Frozen scale

    Reference 2026-Q4 fixes the parameters of 40 benchmarks, so scores don't drift.

  5. 5

    Composite Score

    An open-ended score (100 = average model) with a 90% range, plus 5 skill scores.

02

Why not average the scores

Models are tested on different sets of benchmarks. A plain average favours a model run only on easy benchmarks over one submitted to hard ones, and averages taken over different test sets can't be compared with each other.

Model A

Weaker. Tested only on the easiest benchmarks.

  • LiveBench Math81%
  • MMLU-Pro86%
  • LiveBench Reasoning73%
  • MATH Level 594%

Model B

Stronger. Submitted only to the hardest benchmarks.

  • Chess Puzzles31%
  • FrontierCode35%
  • Humanity's Last Exam33%
  • CritPt16%

Plain average

Mean of whatever each model was tested on

Model A
84
Model B
29

Shows A far ahead, though the gap accounts only for which tests each model completed.

Composite Score

Ability on one shared difficulty scale (bars from 50 to 150)

Model A
105
Model B
130

Takes test difficulty into account to rank B higher.

Hypothetical models. Each result is what the fitted 2026-Q4 model predicts for a model of that ability on that benchmark, so the example uses each benchmark's real difficulty.

03

Item Response Theory

Standardized tests such as the SAT and GRE use Item Response Theory to compare test-takers who answered different questions. Epoch AI's Capabilities Index applies the same method to AI models. We use the two-parameter logistic (2PL) model.

Each model gets one ability θ. Each benchmark gets a difficulty b, the ability at which a model is expected to land halfway between random guessing and a perfect score, and a discrimination a, which sets how sharply the benchmark separates weaker models from stronger ones.

Before fitting, every result gets normalized from 0 to 1 based on the benchmark's random-guess floor and its top score. For a four-option multiple-choice quiz, 25% is treated as zero.

Both open and proprietary models, along with every benchmark, are fitted together using maximum a posteriori estimation. Even two models that never faced the same benchmark remain comparable, since each one shares tests with others during the fit.

Expected normalized result

ŷ = σ(a · (θ − b))

θ
model ability
b
benchmark difficulty
a
benchmark discrimination
σ
logistic S-curve, 0 → 1
  • MATH Level 5b -0.83 · a 2.65
  • SWE-bench Verifiedb -0.13 · a 1.38
  • Humanity's Last Examb 1.87 · a 1.03
0%25%50%75%100%−3−2−10+1+2+3+4Model ability θ →
MATH Level 5
99%
SWE-bench Verified
83%
Humanity's Last Exam
29%
Typical benchmark
57%
Composite Score
125.0
Real parameters from the 2026-Q4 reference. Each curve crosses 50% at its difficulty b (open circles). A steeper curve, with a higher a, separates models more sharply near that point. Move the slider to see the expected result on each benchmark, on a typical benchmark, and the llmrun Composite Score for that ability.

04

Which benchmarks count

The score is fitted on the active panel: benchmarks that new models are still being tested on.

  • Still in use

    A benchmark counts if it has a result dated within the last 365 days (using either the source's own date or the model's release date when no source date exists). Saturated older benchmarks like GSM8K and HellaSwag drop out this way.

  • A fixed baseline and ceiling

    Relative ratings such as LMArena's Elo are excluded, because they have no baseline or ceiling to normalize against.

  • Plausible bounds

    Benchmarks where more than 25% of results sit at exactly 0 or 100 are excluded. In that case the scale bounds are probably wrong.

Benchmark difficulty map

  • Coding
  • Agents
  • Math
  • Science
  • Reasoning
  • Overall only
  • Two skills
← easierharder →
  • LiveBench Codingdifficulty -1.70
  • LiveBench Mathdifficulty -1.57
  • MMLU-Prodifficulty -1.05
  • LiveBench Reasoningdifficulty -1.01
  • MATH Level 5difficulty -0.83
  • ForecastBenchdifficulty -0.82
  • SWE-bench Multilingualdifficulty -0.46
  • Fiction.LiveBenchdifficulty -0.37
  • GPQA Diamonddifficulty -0.26
  • DTBenchdifficulty -0.20
  • SWE-bench Verifieddifficulty -0.13
  • AIME 2024/2025difficulty -0.13
  • Aider Polyglotdifficulty -0.09
  • SWE-bench Bash Onlydifficulty 0.05
  • WeirdMLdifficulty 0.37
  • SWE-bench Litedifficulty 0.39
  • ARC-AGIdifficulty 0.44
  • SimpleBenchdifficulty 0.50
  • Surface Evolver Benchdifficulty 0.59
  • Terminal-Benchdifficulty 0.61
  • FrontierMathdifficulty 0.81
  • SciCodedifficulty 0.99
  • ARC-AGI-2difficulty 1.05
  • BALROGdifficulty 1.10
  • DeepSWEdifficulty 1.11
  • LMCAdifficulty 1.18
  • ProofBenchdifficulty 1.20
  • APEX-Agentsdifficulty 1.22
  • SimpleQAdifficulty 1.23
  • ALE-Benchdifficulty 1.25
  • FrontierMath Tier 4difficulty 1.34
  • Vending-Bench 2difficulty 1.59
  • GSO-Benchdifficulty 1.73
  • Mystery Game Puzzlesdifficulty 1.73
  • Chess Puzzlesdifficulty 1.78
  • FrontierCodedifficulty 1.79
  • Humanity's Last Examdifficulty 1.87
  • CritPtdifficulty 2.41
  • CL-benchdifficulty 3.88
  • CL-bench Lifedifficulty 4.38
All 40 reference parameters
BenchmarkSkillDifficulty bDiscrimination aSource
LiveBench CodingCoding−1.700.46LiveBench
LiveBench MathMath−1.570.82LiveBench
MMLU-Pro—−1.051.44TIGER-Lab MMLU-Pro
LiveBench ReasoningReasoning−1.010.83LiveBench
MATH Level 5Math−0.832.65Epoch AI
ForecastBenchReasoning−0.820.31Epoch AI
SWE-bench MultilingualCoding−0.460.62SWE-bench
Fiction.LiveBench—−0.371.73Epoch AI
GPQA DiamondScience−0.261.67Epoch AI
DTBenchReasoning−0.201.37Epoch AI
SWE-bench VerifiedAgents−0.131.38SWE-bench
AIME 2024/2025Math−0.132.67Epoch AI
Aider PolyglotCoding−0.092.13Epoch AI
SWE-bench Bash OnlyAgents+0.051.50SWE-bench
WeirdMLCoding+0.371.15Epoch AI
SWE-bench LiteCoding+0.391.04SWE-bench
ARC-AGIReasoning+0.442.91Epoch AI
SimpleBenchReasoning+0.500.90Epoch AI
Surface Evolver BenchCoding+0.591.69Epoch AI
Terminal-BenchAgents+0.611.65Epoch AI
FrontierMathMath+0.812.06Epoch AI
SciCodeCoding, Science+0.990.51Epoch AI
ARC-AGI-2Reasoning+1.053.64Epoch AI
BALROGAgents+1.100.68Epoch AI
DeepSWEAgents+1.111.57Epoch AI
LMCAReasoning+1.180.90Epoch AI
ProofBenchMath+1.203.45Epoch AI
APEX-AgentsAgents+1.220.90Epoch AI
SimpleQA—+1.231.01Epoch AI
ALE-BenchCoding+1.251.30Epoch AI
FrontierMath Tier 4Math+1.343.52Epoch AI
Vending-Bench 2Agents+1.591.58Epoch AI
GSO-BenchAgents+1.731.59Epoch AI
Mystery Game PuzzlesReasoning+1.731.42Epoch AI
Chess PuzzlesReasoning+1.781.40Epoch AI
FrontierCodeCoding+1.791.02Epoch AI
Humanity's Last ExamScience+1.871.03Epoch AI
CritPtScience+2.411.38Epoch AI
CL-bench—+3.880.46Epoch AI
CL-bench Life—+4.380.52Epoch AI
The 40 benchmarks of the 2026-Q4 reference, placed by fitted difficulty. 0 is the average model in the fit. Hover a benchmark to see its parameters and source.

05

From ability to the llmrun Composite Score

Ability θ has no natural units, so we convert it with a fixed straight line: Score = 100 + 25 × θ.

100 represents the average model for the 2026-Q4 reference field, where θ equals 0. Each 25 points corresponds to one standard deviation of capability within that area.

There's no ceiling here: stronger future models simply score higher, with no need to rebase the scale to make room for them. Since the conversion is a straight line, a 10-point gap means exactly the same thing whether you're at 70 or 140.

A second way to read the same ability is the expected result on a typical benchmark: the predicted result, from random guessing (0%) to a perfect score (100%), averaged over all 40 reference benchmarks. Benchmarks a model was never run on count with the fit's prediction. This reading flattens out as it approaches 100%, which is why it is not the headline number.

Reading the scale

Ability θScoreTypical benchmark
−2508%
−17517%
010034%
+112557%
+215078%

Each standard deviation of ability adds 25 points. The typical-benchmark column follows an S-curve that levels off near 100%, so equal steps in ability add unequal percentages.

06

A fixed scale

Rerunning the fit with every data update would shift the scale to re-center constantly; adding a single tough benchmark would change every model's score. That's why we lock the scale in place.

Frozen reference

Difficulty and discrimination for the 40 reference benchmarks are fixed in reference 2026-Q4, created 2026-10-03.

New benchmarks are calibrated in

A benchmark added later is calibrated onto the existing scale. The scale itself does not move to fit it.

Scores follow a model's own results

Adding other models or new benchmarks does not move a model's score. It changes mainly when new results for that model arrive. Its range and skill scores can shift slightly as the fit is refined.

The current method is v3-irt-4 on reference 2026-Q4. If the scale is ever re-based, that will ship as a new version with a published old-to-new conversion table.

Every change to the method, the display or the reference is listed under Changes and rebases.

07

The 90% range

Each score displays a 90% range, calculated as the score at θ ± 1.645 standard errors using Laplace approximation; this makes it symmetric about the score. Benchmarks that are fewer or less informative result in a wider range.

Score
  • Well covered

    Many informative boards across all skills

    130.090% range 126–134
  • Thinly covered

    Meets the 4-benchmark minimum

    130.090% range 112–149
Two hypothetical models sharing an estimated ability of θ = 1.2. The dot marks the score, while the band shows its 90% range.

08

When a score is published

A score based on a handful of results would look more precise than it is, so a model needs a minimum amount of evidence first.

Overall Composite Score
At least 4 eligible benchmarks across at least 2 categories, one of which is reasoning or coding — or 3 benchmarks whose results already narrow the score to a 90% range of at most 15.6 points. Either way the results must come from at least 2 different benchmarks: the categories of one benchmark, such as LiveBench, count once.
Skill score
At least 2 benchmarks in that skill. Otherwise the skill is marked as not enough data.

Models without a published Composite Score are ranked on Traction in hardware lists.

09

Skill scores

Each skill represents a fixed set of benchmarks. The skill score estimates how well the model performs based solely on those benchmarks, using the same scale as the overall score. A single benchmark may contribute to two different skills; SciCode, for instance, counts toward both coding and science.

  • Coding

    9 benchmarks

    Writing and fixing code that must run and pass tests.

    LiveBench Coding · Aider Polyglot · SciCode · WeirdML · SWE-bench Multilingual · SWE-bench Lite · FrontierCode · ALE-Bench · Surface Evolver Bench

  • Agents

    8 benchmarks

    Long multi-step tasks in real environments: repositories, terminals, simulated businesses.

    SWE-bench Verified · SWE-bench Bash Only · Terminal-Bench · DeepSWE · GSO-Bench · APEX-Agents · Vending-Bench 2 · BALROG

  • Math

    6 benchmarks

    From competition problems to research-level proofs.

    AIME 2024/2025 · MATH Level 5 · LiveBench Math · FrontierMath · FrontierMath Tier 4 · ProofBench

  • Science

    4 benchmarks

    Graduate-level physics, chemistry and biology, plus scientific code.

    GPQA Diamond · CritPt · SciCode · Humanity's Last Exam

  • Reasoning

    9 benchmarks

    Novel puzzles, deduction, planning and forecasting.

    ARC-AGI · ARC-AGI-2 · SimpleBench · LiveBench Reasoning · Chess Puzzles · DTBench · LMCA · Mystery Game Puzzles · ForecastBench

  • Planned

    Knowledge, Long context, Instruction following, Multilingual, Vision. We'll add these once enough open models share public results for a fair ranking.

10

Validation

We withhold part of the data to refit and measure how well the fit predicts the held-out results (5-fold cross-validation). Error uses RMSE on a 0–1 normalized scale, meaning lower is better.

Held-out prediction error (RMSE)

Composite Score (IRT)
0.093
Model offset + board mean
0.177
Board average only
0.246
Dropping any one big benchmark and refitting shifts the top-20 ranks by no more than about 5 places.

11

llmrun Composite Score vs Fit

The two ratings answer different questions and are computed separately.

Composite Score · open scale, 100 = average

How capable is the model?

Independent of hardware; the figure remains identical whether running on a laptop or a data-center GPU.

Fit · S to F

How well does it run on my hardware?

VRAM headroom and speed on a specific GPU or device. How Fit (S–F) works

12

Limitations

Known gaps in the score and how we deal with them.

Contamination
A model trained on a benchmark's questions scores above its real ability. Benchmarks with fresh, rotating or private question sets (LiveBench, FrontierMath, ARC-AGI-2) reduce this effect but cannot remove it.
Self-reported vs independent
Some leaderboards accept runs submitted by developers, with their own scaffolds and settings. Independent evaluations are harder to game. We use each source's published figure as is.
Effort and thinking variants
Sources list proprietary models across multiple reasoning-effort settings, but we consolidate them into a single row per model. For every benchmark, we take the result from the highest setting available; if nothing higher exists, we fall back to the default or an even lower one.
Sparse coverage for small models
Small open models are rarely submitted to frontier benchmarks, so many fall short of the minimum or get wide ranges. A missing score means there is not enough evidence. It does not mean the model is weak.
English-centric
Almost every reference benchmark is in English. Multilingual ability is not measured yet.

13

Sources

All results are published by these organisations. llmrun normalizes them and runs the IRT fit.

  • Epoch AI Benchmarking Hub

    Most of the panel: independent runs of frontier reasoning, math, science, coding and agent benchmarks (CC-BY).

    32 in reference

  • LiveBench

    Coding, math and reasoning splits designed to resist contamination. New questions are added on a rolling basis.

    3 in reference

  • SWE-bench leaderboards

    Official SWE-bench Verified, Bash Only, Lite and Multilingual results, scored on whether the model fixes real GitHub issues.

    4 in reference

  • TIGER-Lab MMLU-Pro

    MMLU-Pro, a harder ten-choice successor to MMLU with more reasoning questions and wide open-model coverage.

    1 in reference

  • LMArena

    Elo ratings from blind head-to-head human votes. Shown on separate leaderboards and not used in the score, because Elo is a relative rating, not a 0–100 result.

    Not in score

Details for every benchmark are in the benchmark guide, while the complete rankings appear on the llmrun Composite Score leaderboard.

14

Changes and rebases

Every change to the method, the display scale, the reference or the way lists use the score, newest first. Entries are added, never rewritten.

  1. v3-irt-4Method

    Second publication route, benchmark families, LiveBench 2026

    A model can now also get an overall score from 3 benchmarks when they already narrow it to a 90% range of at most 15.6 points. Every published score must now draw on at least 2 different benchmarks: the categories of one benchmark, such as LiveBench, count once. Three categories of the 2026 LiveBench release (Reasoning, Coding, Long-Horizon) joined the score as new benchmarks, and Chess Puzzles follows Epoch AI's re-run of that benchmark.

    Effect: Open models with a published score went from 94 to 100: eight gained one and two lost theirs (Llama 3.2 1B and Gemma 3 1B, whose Chess Puzzles results the source no longer publishes). The largest change to an existing score is 3.4 points (Muse Spark Open). The top 20 contains the same models, with two pairs of neighbours swapping places.

  2. v3-irt-3Method

    Active panel dated by each result's own date

    A benchmark stays in the active panel while it has a result dated within the last 365 days. Each result is now dated by its own source date; a model's release date only dates results whose source gives none. Before, a recent model release could keep an old board active.

    Effect: SWE-bench Lite (results last dated 2025) left the panel. No model lost its score; the largest change is about 1 point (DeepSeek V3.2).

  3. namingDisplay

    Renamed to llmrun Composite Score

    Same method, scale and numbers; only the name changed to make clear the score combines public benchmark results.

    Effect: None on values or order.

  4. ranking

    Hardware lists rank on the llmrun Composite Score

    GPU, device and homepage lists use a model's llmrun Composite Score as its quality signal where one is published. Models without one are ranked on Traction. Fit now reserves memory for a 16K-token context.

    Effect: Hardware list order changed. Fit grades now include room for a 16K-token context, so some tight fits grade lower.

    How Traction works

  5. v3-irt-3Display

    Open scale: 100 + 25·θ

    The Score is now a straight-line mapping of ability: 100 is the average model of the 2026-Q4 reference field and every 25 points is one standard deviation of ability. There is no upper limit. Same reference and same fit as v3-irt-2.

    Effect: Every model's number changed, but the order of models did not. Old 0–100 values are not comparable with new ones, and there is no exact linear conversion, because the old display curved off towards 100. Compare models within one version.

  6. v3-irt-2Launch

    llmrun Score launched

    An Item Response Theory fit over 40 reference benchmarks, with the scale frozen as reference 2026-Q4, a 90% range on every score and five skill scores. Displayed 0–100 as the expected result on a typical benchmark.

    Effect: Replaced the composite benchmark rating on the benchmark pages. A model's score moves only when new results for that model arrive.

  7. v2Method

    Active panel

    The composite reads only the benchmarks current models are still submitted to, and a model needs at least 4 of them for an overall rating.

    Effect: Models rated mostly on saturated older benchmarks dropped. Models with fewer than 4 active benchmarks lost their overall rating.

  8. v1Launch

    Benchmark rating

    A composite of normalized benchmark scores: the average within each category, then an equal-weight average across categories.

    Effect: First overall rating on llmrun.

15

Frequently asked questions

What is the llmrun Composite Score?
A capability score for language models, derived from public benchmark results using Item Response Theory. 100 represents the average frozen 2026-Q4 reference field model, with every 25 points equaling one standard deviation in ability. The scale lacks an upper limit, meaning stronger future models will simply achieve higher scores.
Why not just average a model's benchmark scores?
Each model is tested on its own mix of benchmarks, so a plain average mostly reflects how hard that mix was. The llmrun Composite Score fits all models and all benchmarks together with Item Response Theory, which estimates each benchmark's difficulty and takes it into account.
Does llmrun run the benchmarks itself?
No. The score relies solely on results from Epoch AI Benchmarking Hub, LiveBench, SWE-bench leaderboards, TIGER-Lab MMLU-Pro. Every source gets credit here and includes links.
Why does every score come with a range?
It is the 90% interval of the estimate. A model with results on many informative benchmarks gets a narrow range, and one that barely meets the minimum gets a wide one. If two ranges overlap heavily, treat the models as roughly tied.
Will a model's score change when new models or harder benchmarks are added?
No. Benchmark parameters are frozen in reference 2026-Q4, and new benchmarks are calibrated onto that scale. The overall score changes mainly when new results for that model come in, though its range and skill scores can shift slightly as the fit is refined.
Why is the score not capped at 100?
A capped score clumps the strongest models at the top, leaving no space for better ones. The llmrun Composite Score converts ability directly into a straight line: 100 + 25 × θ. This means differences carry equal weight across the entire scale, so a much stronger model can reach scores like 160 or 200 without needing to rebase the scale.
Why isn't LMArena part of the llmrun Composite Score?
LMArena publishes an Elo-style rating built from human preference votes. The rating only says how often voters preferred one model over another, so it has no fixed baseline or ceiling to normalize against. Arena ratings are shown on their own leaderboards.
Why doesn't a model have an llmrun Composite Score yet?
An overall score requires results from at least 4 eligible benchmarks across at least 2 categories, including reasoning or coding, or from 3 benchmarks that already narrow the score to a 90% range of at most 15.6 points. Either way the results must come from at least 2 different benchmarks, so the categories of one benchmark (such as LiveBench) never publish a score on their own; meanwhile, a skill score needs at least 2 benchmarks within that specific area. Many small or new open models haven't been submitted to enough public leaderboards yet.
How is the llmrun Composite Score different from Fit (the S–F rating)?
The llmrun Composite Score rates the model itself and does not depend on hardware. Fit, the S–F rating, rates how well the model runs on a given GPU or device, based on VRAM headroom and speed. A strong model can get an F on a small GPU, and a weaker one an S.