October Bullpens: The Club That Needs More Pitchers Usually Loses
Since 2010 the postseason club that used fewer pitchers won 320 of 482 games, 66.4%, against 52.4% in the regular season. Why the count only matters in October.
Category
Data Deep-Dives
Long-form, data-first investigations into league-wide trends — usage patterns, rule-change effects, and the stories hiding in the aggregate numbers.
Rest or Rust? 134 Postseason Series Say a Layoff Costs Nothing
In 134 postseason series with unequal rest, the more-rested club won 68 against 70.7 its record predicts. Long layoffs and byes show no rust in Game 1 either.
What a Series Lead Is Worth: 381 Postseason Series Against a Coin Flip
Up 1-0, up 2-0, up 3-1: 381 postseason series since 1903 say a lead is worth about what a coin flip predicts. Momentum doesn't show up in the data; home field does.
The Placed Runner Ended the Long Game. October Doesn't Use It.
Since the runner on second arrived, 71.4% of extra-inning games end in the 10th, up from 44.8%, and home teams gained nothing. The postseason drops the rule.
The .500 Division Winner: Baseball's Oldest Floor Is About to Fall
No division winner has ever finished below .500, and the fewest wins any managed is 82. The 2026 AL West champion lands under that 52.4% of the time.
September Is Two Months: Baseball's Scoring Slide
September 1-15 is the season's highest-scoring stretch at 8.98 runs a game. From the 16th on it falls to 8.53, below April. Fifteen seasons, and 2026's test.
Do Out-of-It Teams Quit in September? 15 Seasons Say No
Clubs 10+ games out on Sept. 1 won 37.8 fewer games than expected across 15 Septembers, a quarter-win each. The real sag comes in August, right after the deadline.
Who Wins the Tie? 2026's Playoff Tiebreakers, Computed
No Game 163: a tied record already has an owner. 16 of 25 race tiebreakers are clinched, 8 against the team ahead, and the Guardians would lose both that matter.
Does a Hot September Carry Into October? 139 Series Say Barely
The hottest team in each October field has won 1 of the last 21 World Series. Across 139 postseason series, a hot September is worth about what regression says.
The Head-to-Head Endgame: Which September Races Can Still Settle Themselves
Braves-Phillies have seven head-to-heads left across a 4-game gap. The 2-game AL West has zero. St. Louis cannot touch anyone ahead. September leverage, mapped.
Why the Best Team Loses in October: 31 Seasons of Short-Series Math
The best regular-season team won 8 of the wild-card era's 31 World Series. The math says that's about right — and the median champion ranked fourth.
The Playoff Bar: What an October Seat Actually Costs Now
The 90-win rule is 3.7 wins out of date. Since the third wild card, the last seat has averaged 86.8 wins — and the 2026 AL is pacing to sell one for 81.
The 2026 Playoff Races, Priced: Three Live Divisions, Two Crowded Last Seats
Every 2026 race against one yardstick (the 4.1 games luck can still move in 34), plus the magic-number formula from scratch and every live clinch countdown.
The Strongest Division in 2026: The Wins Say AL East, the Runs Say NL Central
Strip out intra-division games and the AL East is 237-195 vs everyone else — but the NL Central's +185 run differential is the stronger claim. A dated audit.
Is Beating Your Run Differential a Skill? 90 Season Pairs Say No
Beating your Pythagorean record doesn't repeat (r=0.00 across 90 season pairs), and fitting the exponent to 2023 gives 1.69, which barely matters.
Two Teams, One Town: MLB's Crosstown Pairs Sit Farther Apart Than Strangers
MLB's four shared markets, 2015-2024: crosstown pairs averaged 19.4 wins of separation — more than random pairs (15.0) — and won together in just 7 of 36 seasons.
Hitting vs. Pitching: Which Side of the Ball Bought Wins in 2024?
Team OPS tracked 2024 win% at r=+0.79 and team ERA at −0.74 — hitting edged pitching, flipping 2023's verdict, and together the two explain 91% of the standings.
The .500 Gravity Well: MLB's Winners Regress Harder Than Its Losers Recover
Across 210 back-to-back season pairs, 2015-2024, a .600+ finish cost 11.0 wins the next year — 51% of the edge over .500. Sub-.400 teams won back just 36% of theirs.
The Offense Gap Collapses: 2026's Best and Worst Offenses Are the Closest Since at Least 2021
The gap between MLB's best and worst offense is 1.54 runs a game in 2026 — the narrowest since at least 2021 after four widening finals. It's the floor that moved.
The Parity Check: 2026's Standings Are Tighter Than Every Final Season, 2015-2024
2026's win% spread is .062 through an average of 97.3 games — under all nine bundled final seasons (.063-.096), even though partial seasons should run wider.
The Schedule They Have Left: Remaining Strength of Schedule for 2026's Contenders
576 games remain. League-wide, remaining-schedule tilt now spans under 4 wins — and the Cubs' chase of the Brewers is the one race where it matters. Through Aug 15.
Who Really Wins the Close Ones? 2026's One-Run Records Are Mostly Noise
The Phillies are 19-6 in one-run games and 35-37 in the rest. Across 2026, one-run win% tracks other-game win% at just r=0.16 — close games are mostly coin flips.
How Historic Is the Dodgers' Run Differential? 2026's Extremes Against Four Seasons of Finishes
The Dodgers' +1.75 July pace has regressed to +1.13 — 11 of 120 finished seasons ended higher — while the Athletics' floor turned historic. Updated through Aug 15.
Scoring Is Back: The 2026 Run Environment in Twelve-Season Context
2026 is scoring 8.95 combined runs a game through August 15 — still above 2024 and 2025, but the July surge toward the hottest rates since 2023 has cooled.
What ERA Leaves Out: Unearned Runs and the Gap to Runs Allowed
ERA quietly discards about one run in twelve. Across 2024's 30 teams, RA/9 ran 0.38 above ERA — and runs allowed predicted winning better (r=0.77 vs 0.74).
Offense or Pitching? The 2026 Run-Scoring Map
Run differential blends two skills. Split 2026's teams by runs scored and runs allowed per game to map who wins on offense, who on pitching, and who does both.
The 2026 MLB Regular Season, By the Numbers
The 2026 MLB regular season, final: all 30 records, run differentials and Pythagorean luck, the six division winners, and what 162 games settled.
How Much Does the Home Run Drive Run Scoring?
Each home run was worth about 2.21 runs across 2024's 30 teams, and homers explain 62% of scoring variance — yet OBP tracks scoring better (r=0.93 vs 0.79).
How Many Runs Does a Win Cost? The 10-Run Rule, Checked
Regress wins on run differential across 60 team-seasons (2023-24): one win per 10.7 runs, with the line through exactly 81 wins at zero. The 10-run rule holds.
Is MLB Getting More Top-Heavy? Competitive Balance, 2015-2024
MLB's gap between best and worst widened to a 2019 peak — records spread 15.6 wins around .500 — then eased to 12.3 by 2024. Imbalance crested, not climbed.
K-BB%: The One Pitching Number That Travels
Strikeouts minus walks per batter faced is the pitching skill a defense can't touch — and across 2024's 30 teams it explains 69% of ERA variance (r=-0.83).
Run Differential Predicts Next Year Better Than Wins Do
Across 90 season pairs (2021-2024), Pythagorean win% predicts next year's record better than actual win% does (r=0.57 vs 0.54) — it strips out the timing luck.
Which Hitting Stat Predicts Winning? OBP vs. SLG vs. Average
The Moneyball claim, re-tested on 2024: OBP and OPS correlate with winning at 0.79 while batting average trails at 0.62. Not making outs beats collecting hits.
Consistent Contenders vs. Boom-and-Bust: MLB's Most and Least Steady Franchises
Plot mean win% against year-to-year volatility (2015-2024) and MLB splits into steady winners, boom-and-bust rebuilders, and the consistently mediocre.
Was the AL or NL Stronger in 2023? The Answer Hiding in Run Differential
Summing run differential by league isolates interleague play — the NL edged the AL by 44 runs in 2023, even as the AL East was baseball's best division.
How Competitive Was 2023? Measuring Balance with the Noll-Scully Ratio
MLB in 2023 was about twice as top-heavy as a perfectly balanced league — a Noll-Scully ratio of 2.03. How it splits the standings into talent and luck.
Offense or Defense: What Won in 2023?
Did scoring runs or preventing them matter more in 2023? The real correlations say run prevention edged out offense — and run differential ties them together.
The Luckiest and Unluckiest Teams of 2023
Pythagorean residuals name 2023's luckiest and unluckiest teams: the Marlins beat their run differential by 9 wins while the Padres fell 10 short of theirs.
Home-Field Advantage in Baseball: Small, Real, and Hard to Explain
Baseball has the smallest home-field edge of the major sports. How big it actually is, and the proposed drivers from last at-bat to umpire tendencies.
The Times-Through-the-Order Penalty: Why Pitchers Fade the Third Time
Pitchers get hit harder each time they face a lineup. The times-through-the-order penalty, familiarity versus fatigue, and how it reshaped bullpen usage.
The Death of the Sacrifice Bunt: How Run Expectancy Changed Strategy
The sac bunt has nearly vanished from the non-pitcher game. The run-expectancy math that doomed it, and what the long decline actually looks like.
Bullpen Usage Patterns: What the Data Says About Modern Reliever Management
Starters throw fewer innings than ever and bullpens pick up the slack. What the data says about how modern relievers are actually used.
The Shift Ban, Two Seasons Later: What Actually Changed
Two seasons after the infield shift was restricted, what actually changed? League BABIP, pull-side outcomes, and the gap between the promise and the data.
The Stolen Base Is Back: What the 2023 Rules Did to Baserunning
Bigger bases and a pickoff limit brought the stolen base roaring back. Two seasons of data on attempts, success rates, and what actually changed.