Guides

ERA bands for starters vs. relievers, why league-average ERA shifts year to year, and the two well-documented limitations of the stat.

Why passer rating uses those specific baselines and a 158.3 ceiling, what it deliberately leaves out (sacks, rushing), and how it differs from ESPN's QBR.

A side-by-side worked example showing how two players with identical field goal percentage can have a 25+ point gap in true shooting percentage.

SV% bands for NHL starting goaltenders, why the stat can't see shot quality, and why shootout attempts are excluded entirely.

Handicap Index describes your general ability; Course Handicap adjusts it for one specific course. Here's exactly how WHS converts one into the other.

The formula, why sources disagree on substitute appearances, and what counts as a good clean sheet rate at the professional level.

The official daily pitch maximums and rest-day tables from Regulation VI, the mid-batter exception, the pitcher–catcher restrictions, and why tournament play runs on different rules.

K/9 bands for starters vs. relievers, a worked 200-strikeout example, and the baserunner distortion that makes analysts prefer K% for measuring pure strikeout skill.

Why the BB/9 bands are so compressed, what counts as a walk (intentional walks yes, HBP no), and how baserunner traffic quietly distorts the stat.

K/BB bands, the zero-walk edge case where the ratio is undefined, what the stat deliberately ignores, and why modern analysis prefers K-BB%.

The .1/.2 outs notation, the exact ERA error you get by reading it as a decimal, converting outs to innings, and the 0.0 IP edge case.

The official on-base percentage formula, why sacrifice flies count against you but bunts don't, why reached-on-error is an out, and a fully worked season line.

The total-bases formula worked through a full season line, why SLG isn't actually a percentage, and how ISO separates power from hit volume.

FPCT baselines by position, a worked shortstop season, why the bands differ so much, and the range blind spot that led to Outs Above Average.

Raw passing yards reward volume and game script, not efficiency. Yards per attempt isolates decision-making quality and arm talent, making it the truer measure of quarterback performance across different team contexts.

A high completion percentage can signal conservative play-calling or short-pass dependency rather than genuine accuracy. Pairing it with yards per attempt reveals whether a QB is moving the chains or just checking down.

OPS combines on-base percentage and slugging into one number, but a .900 OPS built on walks and singles plays very differently in a lineup than one built on extra-base power. Understanding which component drives a player's OPS is essential for roster construction.

eFG% adjusts for the extra value of three-pointers while raw FG% ignores shot type entirely. Knowing when each metric misleads you changes how you evaluate scorers in the modern NBA.

GAA depends almost entirely on team defense and pace of play, not goaltender skill. Two goalies with identical GAA can have vastly different underlying performance — save percentage is the only fair single-stat comparison.

WHIP treats every baserunner as equally damaging, but a walk and a hit carry different implications for pitcher control. Breaking WHIP into its H/IP and BB/IP components reveals whether a pitcher's problem is command or contact quality.