About this tool
The Games Behind & Magic Number Calculator turns two teams' win–loss records into the standings figures fans track down the stretch. Games Behind (GB) is computed as ((Leader_W − Team_W) + (Team_L − Leader_L)) / 2 — the average of the wins the trailing team must gain and the losses the leader must add to draw even. A half-game (.5) appears whenever the two teams have played a different number of games.
The magic number tells the leader how many combined leader-wins-plus-rival-losses are needed to clinch: Magic Number = (Total Games + 1) − Leader_W − Rival_L. When it reaches zero the leader has clinched over that rival; the identical value, read from the trailing team's side, is that team's elimination (“tragic”) number. Total games is the season length — 162 for MLB, 82 for the NBA, and so on.
Everything is calculated locally in your browser, so nothing you type leaves your device. Alongside GB and the magic number the tool shows each club's winning percentage (in the standard three-decimal form) and how many games each has left to play, so you can size up a pennant or playoff race at a glance. Enter the leader's and the chasing team's records plus the season length to get started.