Sprint Speed and Baserunning Metrics
What Statcast sprint speed measures in feet per second, what a bolt is, how stolen-base value and baserunning runs are calculated, and why a fast player is not always a good baserunner.
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Strikeout and Walk Rates: K%, BB% and What They Say About a Player
K% and BB% divide strikeouts and walks by plate appearances or batters faced. Learn how to compute them, how they differ from per-nine rates, why they settle early in a season, and what they miss.
The Changeup and the Splitter: The Pitches That Take Speed Off
How the changeup and the split-finger fastball work: grips, arm speed, spin, why one fades and the other falls, and why pitchers lean on them against hitters who bat from the opposite side.
The Curveball and the Knuckle Curve: Why It Drops
The physics of the curveball explained with worked arithmetic: topspin, the Magnus effect, why the break looks late, how the knuckle curve differs, and what altitude and youth arm care mean for the pitch.
The Four-Seam Fastball and the Sinker: Grip, Movement and Use
How the four-seam fastball and the sinker are gripped, why one seems to rise and the other sinks, how pitchers combine them, and which statistics show whether each pitch is working.
The Knuckleball Explained: A Pitch That Barely Spins
How the knuckleball works, why it flutters, and what the careers of Hoyt Wilhelm, Phil Niekro, Wilbur Wood, Charlie Hough, Tim Wakefield and R. A. Dickey show about the pitch and its limits.
Is the Sacrifice Bunt Worth It? The Run Expectancy Math
Run expectancy tables show why a sacrifice bunt usually costs a team runs, and when it still makes sense: weak hitters, late and close games, and extra innings. Worked examples included.
The Slider, the Sweeper and the Cutter: Breaking Balls Explained
How the slider, the sweeper and the cutter are gripped and thrown, why each one moves the way it does, and what league strikeout numbers say about the rise of pitches that bend sideways.
What Old Box Scores Tell Us and What They Do Not
Which statistics exist for which eras, why caught stealing, sacrifice flies and saves have gaps, what Retrosheet and the historical record add and miss, and how to read old numbers without being fooled by blanks.
The Stolen Base Break-Even Point: How Often a Runner Has to Succeed
How run expectancy gives a break-even success rate of roughly 70 percent for a steal of second, why it changes with outs and base, and how the 2023 rule changes moved the league's real success rate to 80 percent.
The Three True Outcomes: Walks, Strikeouts and Home Runs Since 2000
About one plate appearance in three now ends in a walk, a strikeout or a home run, up from fewer than three in ten in 2000. The numbers by decade and season, what drove the change, and what the rule changes of 2023 did.
WAR Explained: What Wins Above Replacement Counts and What It Cannot
What wins above replacement measures, how hitters and pitchers are credited, why Baseball-Reference and FanGraphs disagree, how to read the scale, and where the statistic stops being reliable.
What Is a Quality Start? Pitcher Workload Metrics Explained
A quality start is six or more innings with three or fewer earned runs. This guide explains the definition, its origin, its worked arithmetic, its flaws and the other measures of how much a starting pitcher works.
WHIP Explained: The Pitcher's On-Base Measure
WHIP is walks plus hits per inning pitched. Learn the formula, what a good number is in each era, where the statistic came from, how it compares with ERA, and the flaws that keep it from being the whole story.
Win Probability, Leverage Index and Win Probability Added
How win probability, leverage index and win probability added are built from historical game states, how to read them, and what they can and cannot say about a player or a decision.
wOBA Explained: Weighting Every Way to Reach Base
Weighted on-base average counts a walk, single, double, triple and home run at their real run values. This guide covers the formula, linear weights, two worked examples and how to read the number.
wRC+ Explained: The Number That Compares Hitters Across Parks and Years
wRC+ turns a hitter's run creation into a scale where 100 is league average, adjusted for park and season. Learn the formula, a worked example, how to read it and what it leaves out.
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