Methodology · fan project · baseball history engine

About Chasing .400

Most stat sites answer “who leads MLB today?” Chasing .400 answers the better morning question: who is on a historic pace, how far from immortality are they, and what exactly must happen from here?

Fan-built. Formula-driven. Not affiliated with MLB.

Chasing .400 is a fan project by baseball fan @ericatkins. The site provides original analysis and historical context using publicly available baseball statistics.

Daily briefing

Every morning starts with the story of what changed overnight: milestones crossed, chases strengthened, and historic paces that faded.

Record Radar

Every active chase is normalized into one radar: batting, pitching, team history, Statcast outliers, milestones, and negative history.

The .400 Watch

The brand is anchored to Ted Williams’ .406 in 1941 — the last .400 season in the AL/NL — but the engine tracks every meaningful chase.

The math, shown in full

Simple formulas, visible assumptions

Every number on the site should be explainable. Projections default to team-game pace: current total ÷ team games played × 162.

.400 now ceil((.400 × AB − H) / 0.6)

Consecutive hits needed to reach .400 immediately.

Next N AB ceil(.400 × (AB + N) − H)

Hits needed over a chosen number of upcoming at-bats.

Projected AB AB ÷ team games × 162

Full-season at-bat projection using team pace.

Finish .400 ceil(.400 × projected AB) − H

Rest-of-season hits needed to finish at .400.

Counting stats total ÷ team games × 162

Projected home runs, strikeouts, wins, saves, runs, and other counting totals.

Lahman + Retrosheet

History is evidence, not decoration

The current MLB feed tells us what happened now. The SABR Lahman Baseball Database supplies completed-season, career, age, position, franchise, award, and record context. Retrosheet supplies the game-by-game timeline: exact season checkpoints, streaks, lineups, substitutions, and play sequences. Chasing .400 combines those layers only after resolving player and team identity.

Σ

Lahman: the completed record

Used for “Only X seasons ever,” all-time and franchise ranks, age cohorts, record lineage, historical season twins, and career-path comparisons.

Retrosheet: how history unfolded

Used for exact pace checkpoints, empirical chase outcomes, streak survival, near misses, game-state context, comebacks, collapses, and unusual play sequences.

Evidence-backed narratives

Each historical card retains its source, comparison cohort, sample size, calculation version, and confidence. Optional context disappears rather than inventing an answer when coverage is insufficient.

What readers will see

More than a straight-line projection

A chase can now show its exact historical checkpoint, the median finish of comparable chases, the percentage that reached major thresholds, and the closest completed season by statistical shape.

Coverage and confidence

Historical records are not uniformly complete

Retrosheet accounts may be verified, deduced, partial, or box-score-only depending on the game and era. The site should label those differences and suppress claims that cannot meet the configured evidence threshold.

Feasibility labels

How to read the chase cards

On pace

Projection meets or exceeds the target.

Near pace

Within roughly 8% of the target.

Long shot

Reachable, but requires a meaningful acceleration.

Extreme

Requires a historically implausible run.

Impossible

The math has effectively closed the door this season.

Record modes

Modern view and official record-book view

The brand is anchored to Ted Williams’ .406 in 1941 — the last .400 season in the AL/NL. The official MLB record book now also includes Negro Leagues seasons, led by Josh Gibson’s .466 in 1943, so record pages can show both views.

Data

Daily snapshots after games go final

Player and team statistics come from MLB’s public Stats API. Pitch velocity, exit velocity, and launch angle come from Baseball Savant / Statcast. Snapshots are taken once daily after all games are final, and every page shows a freshness timestamp.

Stewardship

What Chasing .400 is trying to do

We add value through

  • Original pace calculations
  • Historical comparisons
  • History Score and Record Radar
  • Daily narrative summaries
  • Clear links back to source context

We avoid

  • Copying editorial text or tables
  • Implying MLB affiliation
  • Overusing logos, marks, or headshots
  • Scraping aggressively
  • Hiding assumptions behind black-box math

Start here

See who moved closer to baseball history today.

Today’s Briefing