The Number — Regression & Market Edges
Step 4 of the Conditions Game: Is the market pricing the average or today's conditions?
You should read this if:
You bet MLB props and want to understand the mental models that drive outcomes.
The Core Insight
"The market always prices the matchup. Your edge is everything else: the environment it missed, the regression it has not adjusted for, the platoon advantage it averaged over."
The MLB Mental Model
BABIP Deviation
Career BABIP vs current — the #1 regression signal
Predicts: Hot streaks at .350+ BABIP will come down; cold streaks at .250 will recover
FIP-ERA Gap
The most reliably predictive signal in baseball
Predicts: ERA 4.50 / FIP 3.00 = market is overpricing earned runs
xwOBA vs wOBA
Statcast quality of contact vs actual results
Predicts: Positive gap = unlucky (buy), negative gap = lucky (sell)
LOB% vs 72%
Sequencing luck the market has not caught
Predicts: 85% LOB = lucky, earned runs will rise; 60% = unlucky, will improve
Framework in Action: Fading the Hot Streak
A hitter is batting .350 through April. The market prices his hits over aggressively. But his BABIP is .420 (career .305) and his xBA is .265. Statcast says his contact quality deserves a .265 average, not .350. The gap is batted-ball luck. This gap ALWAYS closes. The market prices the hot streak. You price the regression.
When to Apply This Framework
- ✓BABIP running .050+ above or below career norm — strong regression signal
- ✓FIP-ERA gap > 0.5 points — market is using ERA instead of true talent
- ✓xwOBA-wOBA gap > .030 — Statcast says results don't match contact quality
- ✓LOB% above 80% or below 65% — sequencing luck about to correct
When to Pass
- ⚠️Regression signals conflict with each other (some say over, some say under)
- ⚠️Market has already moved to reflect the regression (line already adjusted)
- ⚠️Not enough sample size for regression signals to be meaningful (first week of season)
Key Takeaways
- ✓The market prices the average. Your edge is pricing today's conditions.
- ✓BABIP deviation is the single most important regression signal in baseball
- ✓Half the battle is identifying who is running hot or cold due to luck and betting on the correction
How DMP Helps
DMP highlights BABIP deviation, FIP-ERA gaps, and xwOBA gaps directly in the research panel. The AI Insights tab synthesizes all regression signals into a conditions assessment.