Model Transparency

Our prediction model is fully open about its methodology and accuracy. No black boxes.

63.4%
Test Accuracy
402 fights (2023)
0.697
AUC-ROC
Discrimination
0.626
Log-Loss
vs 0.693 coin flip
0.219
Brier Score
vs 0.250 coin flip

How It Works

Data

Every UFC fight since 1994, scraped from UFCStats.com. Fighter stats computed as point-in-time snapshots to prevent data leakage.

Model

LightGBM + CatBoost ensemble (65/35 blend), tuned with Optuna (50 trials each). Trained on pre-2022 data, validated on 2022, tested on 2023.

Features

24 features including Elo ratings, rolling fight stats, defensive metrics, style matchups, and market odds when available.

Confidence Scaling

The model's confidence labels reflect real accuracy. When we say “Strong”, we mean it.

Toss-up (<55%)
48.8%
n=82
Lean (55-65%)
57.9%
n=145
Strong (65-75%)
69.0%
n=100
Very Strong (>75%)
82.7%
n=75

Calibration

When the model says 70%, does that fighter actually win ~70% of the time? Closer to the diagonal = better calibrated.

Predicted RangeMean PredictedActual Win RateFightsDifference
10-20%17.2%18.2%11+1.0pp
20-30%25.6%21.6%51-4.0pp
30-40%35.7%40.7%54+5.0pp
40-50%45.5%51.3%78+5.8pp
50-60%54.9%60.5%81+5.6pp
60-70%64.9%58.3%60-6.6pp
70-80%74.5%66.7%42-7.8pp
80-90%85.0%95.7%23+10.7pp

Performance by Weight Class

Heavyweight
75.9%n=29
Women's Strawweight
72.0%n=25
Bantamweight
68.3%n=41
Lightweight
67.3%n=55
Women's Bantamweight
66.7%n=12
Welterweight
64.7%n=51
Flyweight
60.7%n=28
Featherweight
59.2%n=49
Light Heavyweight
53.6%n=28
Middleweight
52.4%n=42
Women's Flyweight
51.7%n=29

What Drives Predictions

Top features ranked by SHAP importance (mean absolute impact on predictions).

1Market odds lean
0.3527
2Age difference
0.1701
3Elo rating gap
0.1377
4Damage absorption rate
0.0794
5Takedown rate advantage
0.0718
6Striking defense advantage
0.0714
7Striking volume advantage
0.0659
8Reach advantage
0.0606
9Striking accuracy edge
0.0547
10Knockdown rate advantage
0.0368

Honest Assessment: Model vs Market

On fights with betting odds (294 of 402 test fights), the closing line achieves 68.0% accuracy vs our model's 64.6%. The market is hard to beat — it aggregates thousands of sharp bettors.

Where our model adds value:

  • Fights without odds data — we still predict at 60.2% accuracy
  • Structural analysis: Elo, style matchups, and stat differentials give context the line doesn't
  • Early line detection: spots value before lines sharpen
  • High-confidence picks (>75% model probability) hit at 82.7%

Training Details

Training Set
6,288 fights
1994-03-11 to 2021-12-18
Validation Set
505 fights
2022-01-15 to 2022-12-17
Test Set
402 fights
2023-01-14 to 2023-09-23
Ensemble Weights
LightGBM 65% / CatBoost 35%
Validation log-loss: 0.6021