Guide · 8 min read

How the PropsBot Model Works

The 14 factors, their empirical accuracy, and what "Predictability 68" actually means.

The model in one sentence

PropsBot BKFC is a transparent factor-based scoring system — not a black-box machine-learned model. For every bout we score the two fighters across 14 dimensions, combine via weighted sum, pass through a logistic function, then blend with the de-vigged market moneyline. The output is a probability per fighter that we display as Advantage Score 0-100, paired with a Predictability Index 0-100 that captures how much you should trust the pick.

Historical accuracy (point-in-time backtest)

Over 325 completed bouts from 2023-2025, reconstructing each fighter's state as of the bout date (no post-bout leakage):

  • Full-model accuracy: 59.8% on 127 picks where the model had enough signal to lean. 198 bouts were skipped as toss-ups (45-55% range).
  • Brier score: 0.2473 — better than the 0.25 naive-50% baseline.
  • Edge vs coin-flip: +9.8 percentage points.
  • Baseline comparison: picking whichever fighter has the better BKFC win rate goes 55-41 (57.3%). We beat that by 2.5pp.

In combat-sports betting, 58-60% accuracy on model-filtered picks is in the range a competitive professional handicapper operates. We're honest that 40% of our picks lose. Bet accordingly.

The 14 factors and their weights

Weights are hand-set informed priors. Every four weeks we recalibrate against new data; factors with small backtest samples (n < 30) keep their prior weight until enough history accumulates to override.

ELO Rating (opponent-quality adjusted)
16%
Recent Form (last 5, recency-weighted)
13%
BKFC Record (Bayesian-smoothed)
11%
KO Rate
11%
Age (decline past 35)
9%
Pro Boxing Background
9%
Reach
8%
MMA Background
7%
Style Matchup
6%
Activity / ring rust
5%
Cut Susceptibility
5%
Strength of Schedule
4%
BKFC Experience
3%
Height
3%
Stance (southpaw edge)
3%
Home Advantage
2%

What Advantage Score means

Simply the model's probability × 100 for that fighter. An Advantage Score of 67 means the model estimates this fighter wins 67% of the time. The two scores in a bout always sum to 100. Scores above 55 indicate meaningful favorites; 46-54 is a toss-up; below 45 is an underdog.

What Predictability means

A 0-100 trust score for the specific pick. It blends:

  • 50% data quality (is there enough history on both fighters to be meaningful?)
  • 30% signal strength (how far from 50/50 is the model?)
  • 20% factor agreement (are most active factors pointing the same direction?)

Predictability 75+ = strong pick. 55-75 = solid. 40-55 = marginal. Below 40 is filtered from the /picks/ board because the model doesn't trust itself.

Market-adjusted prior

When de-vigged moneyline odds exist for a bout, we blend our raw model output 55/45 with the market as a prior. Sharp handicappers anchor to the market and add a data-driven delta — the market has information (injuries, camp news, sharp money) we often lack. Our recommendations are therefore most trustworthy when we agree with the market direction but show a meaningful edge in magnitude.

Shrinkage calibration

Reliability-diagram analysis showed our model was ~8pp over-confident in the 65-70% bucket — when it said 67%, the fighter actually won 60% of the time. We apply a shrinkage factor that pulls probabilities toward 50%: p' = 0.5 + 0.85 × (p - 0.5). This makes high-advantage predictions more honest at the cost of never displaying extreme certainty.

Honest limitations

This is a decision aid, not a crystal ball.

  • 325 training bouts is small. Most factors have fewer than 30 testable samples. We use hand-priors for factors with thin data rather than overfitting.
  • Intangibles aren't captured: camp news, weight cut struggles, in-the-ring injuries, referee tendencies, crowd impact beyond home-country effect.
  • BKFC has a small sample per fighter. A fighter's first 2-3 bouts tell us very little. The model honestly labels these as Low or Very Low confidence.
  • The market knows things we don't. When we disagree with the market by >15pts, 60% of the time the market ends up right. Size your bets accordingly.

Frequently Asked

How accurate is the PropsBot BKFC model?
59.8% on 127 point-in-time backtested picks out of 325 total historical bouts. The model skips toss-up bouts (45-55% range) and only commits to picks where it has meaningful signal. Brier score 0.2473 (baseline 0.25). Edge over coin-flip: +9.8 percentage points.
What's the difference between Advantage Score and Predictability?
Advantage Score is the model's probability × 100 for each fighter (the two scores sum to 100). Predictability is how much you should trust that specific pick — a 67/33 prediction with Predictability 80 is far more bettable than the same prediction with Predictability 30.
Is PropsBot's model machine-learned?
No. It's a transparent factor-based scoring system with hand-set weights that get recalibrated against new historical data. We built a pure-JS logistic regression trainer for comparison; on our 325 training bouts it scored 52.9% cross-validation accuracy, below our 59.8% heuristic baseline. LR didn't beat the heuristic so we didn't deploy it. We'll revisit when we have 1000+ training bouts.