Bullpen ERA & FIP (Last 14 Days)

Overview

This pillar evaluates the recent performance of relief pitching staffs by stripping away defensive variance. It focuses on the last 14 days to identify which bullpens are truly dominant and which are teetering on the edge of collapse due to luck or fatigue.

What It Does

The system aggregates relief pitcher data from the previous two weeks to calculate collective ERA and FIP (Fielding Independent Pitching). It specifically isolates strikeouts, walks, and home runs to determine how well pitchers are controlling outcomes independent of their fielders. This reveals the true structural health of a team's late game defense.

Why It Matters

Most casual bettors focus entirely on starting pitchers and ignore the fact that bullpens often decide the final third of the game. Identifying a bullpen with a lucky low ERA but a high FIP allows traders to exploit mispriced moneyline and total odds before statistical regression hits.

How It Works

We ingest inning by inning data for all active relief pitchers over the trailing 14 day window. We calculate the collective FIP using the constant for the current season to standardize the metric against league averages. Finally, we compare this against the bullpen's actual ERA to highlight discrepancies that indicate imminent regression.

Methodology

FIP is calculated using the formula ((13*HR + 3*(BB + HBP) minus 2*K) / IP) plus the season specific constant. The analysis strictly enforces a rolling 14 day window to capture current form rather than season averages. We exclude position players pitching and apply park factors to normalize performance across different stadium environments.

Edge & Advantage

This provides a significant advantage in Total Runs markets and live trading scenarios where lines often fail to account for a fatigued or overperforming bullpen about to regress to their mean.

Key Indicators

• Bullpen FIP (14 Day)

  high

  Fielding Independent Pitching metric for the relief corps over the last two weeks

• ERA Minus FIP Delta

  high

  The difference between actual results and expected results; large gaps suggest luck

• K minus BB Percentage

  medium

  Strikeout percentage minus walk percentage; the purest measure of dominance

Data Sources

• MLB Advanced Media

  Official play by play data for calculating raw outcomes

• FanGraphs

  Source for FIP constants and park factors

Example Questions This Pillar Answers

• → Will the total runs in Dodgers vs Padres exceed 8.5?
• → Which team will win the race to 5 runs?
• → Will the Yankees bullpen allow a run in the 7th inning or later?

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