Baseball Statistics

What is WAR in baseball?

WAR (Wins Above Replacement) is an all-encompassing statistic that attempts to measure a player's total value to their team in one number. It estimates how many more wins a player contributes compared to a replacement-level player — a freely available minor leaguer or bench player. A WAR of 0 means the player performed at replacement level, 2 WAR is a solid starter, 5 WAR is an All-Star caliber season, and 8+ WAR represents an MVP-level performance. Both Baseball Reference (bWAR) and FanGraphs (fWAR) calculate WAR using slightly different methodologies.

What does OPS measure?

OPS stands for On-base Plus Slugging and is calculated by adding a player's on-base percentage (OBP) to their slugging percentage (SLG). It provides a quick snapshot of a batter's overall offensive production by combining their ability to reach base with their power. An OPS above .800 is considered good, above .900 is excellent, and above 1.000 is elite. While OPS is widely used for its simplicity, analysts note that it slightly undervalues on-base percentage relative to slugging, since getting on base is marginally more valuable per point than extra-base hits.

How is ERA calculated?

ERA (Earned Run Average) is calculated by dividing earned runs allowed by innings pitched, then multiplying by nine. The formula is: ERA = (Earned Runs / Innings Pitched) x 9. This gives you the average number of earned runs a pitcher would allow over a full nine-inning game. Unearned runs — those resulting from defensive errors — are excluded. A league-average ERA typically hovers around 4.00, while an ERA below 3.00 is considered excellent. Modern analytics also use FIP (Fielding Independent Pitching) alongside ERA to isolate a pitcher's performance from their defense.

Is this site affiliated with MLB?

No. Baseball Statistics is an independent educational resource. We are not affiliated with, endorsed by, or connected to Major League Baseball, any MLB team, or any players' association. Our guides are written solely to help baseball fans, fantasy players, and aspiring analysts understand the numbers behind the game through unbiased, practical information.