← Back to Today's Slate

⚾ Bump — Scoring Methodology

How pitcher fat pitch scores and hitter scores are calculated

What is Bump?

Bump scans the daily MLB slate and scores each starting pitcher based on ERA, WHIP, and recent form. The core insight is simple: a bad pitcher is a good betting opportunity. By scoring pitchers on a 0–100 fat pitch scale and surfacing the best opposing hitters, Bump helps identify high-fat-pitch pitching matchups where the edge comes from a hittable starter.

Pitcher Fat Pitch Score— How hittable is today's starter? (0 = dominant, 100 = very hittable)

Hitter Score — How good is this batter against this type of pitcher? (0 = weak, 100 = excellent)

Pitcher Fat Pitch Score

Input Statistics

  • ERA (Earned Run Average) — Earned runs allowed per 9 innings pitched
  • WHIP (Walks + Hits Per Inning) — Base runners allowed per inning. Lower is better for the pitcher
  • BAA (Batting Average Against) — How often opposing batters get hits off this pitcher

Normalization (0–100 scale)

ERA fat pitch = (ERA / 10) × 100 [clamped 0–100]WHIP fat pitch = (WHIP / 3) × 100 [clamped 0–100]BAA fat pitch = (BAA - 0.15) / 0.20 × 100 [clamped 0–100]

Season Score

seasonScore = (ERA fat pitch + WHIP fat pitch + BAA fat pitch) / 3

Recent Form Score

Averages ERA and WHIP fat pitch across the pitcher's last 5 starts. BAA is not available in game log data.

recentFormScore = (avgERA fat pitch last 5 + avgWHIP fat pitch last 5) / 2

Combined Fat Pitch Score (Final)

fatPitchScore = (recentFormScore × 0.60) + (seasonScore × 0.40)

Recent form is weighted 60% because a pitcher's last few outings are more predictive than their full season line.

Fat Pitch Badge Thresholds

ScoreBadgeMeaning
> 65High fat pitch — very hittable, strong bet candidate
40–65Moderate — worth watching, context dependent
< 40Strong pitcher — avoid
AnyNo 2026 starts yet — score based on 2025 season stats

Hitter Score

The Hitter Score rates each batter 0–100 for Total Bases–style outcomes: power, contact, and extra-base tendency — aligned with how TB props pay out.

Formula

tbScore = (SLG × 0.50) + (AVG × 0.30) + (ISO × 0.20) where ISO = SLG − AVG

Stat Weights

  • SLG — 50% weight — Slugging is the most direct proxy for total bases per at-bat
  • AVG — 30% weight — Contact quality; hits are the foundation of total bases
  • ISO — 20% weight — Isolated power (SLG minus AVG); measures extra-base hit tendency

Normalization Ranges

SLG: .300 → 0 to .600 → 100AVG: .200 → 0 to .350 → 100ISO: .000 → 0 to .300 → 100

OBP is excluded — walks and HBP do not count toward Total Bases props.

How to Use Bump

  1. Scan the slate — Find games with red fat pitch badges (score > 65). These are your primary targets.
  2. Click the pitcher — Review season vs recent form. Is the high score driven by recent bad starts or a season-long pattern?
  3. View Batters — Open the modal and look at the top-scored hitters against this starter.
  4. Click a batter — See their full stat breakdown and score components.
  5. Build your bets — Target the opposing team's moneyline, the game total, or individual batter props. Combine your best spots into a parlay or round robin for bigger upside.

Timing

MLB lineups are typically posted 3–4 hours before first pitch (around 3–4pm ET). Bump is most useful after lineups are confirmed. Probable pitchers are usually set the night before.

Limitations

  • Early season small samples — In April, fat pitch scores are based on very few starts. A grey badge means no 2026 data yet — score uses 2025 stats.
  • No splits — The tool does not account for left/right pitcher-batter matchups.
  • No injury data — Always check lineup status before betting.
  • No ballpark factors — Coors Field and other hitter-friendly parks inflate all offensive stats.