FILE -In this April 10, 2014, file photo, John Weber keeps score as he watches a baseball game between Pittsburgh Pirates and Chicago Cubs at Wrgley Field Thursday, in Chicago. The days of batting average, RBIs, wins and ERA telling the whole story ended
Kiichiro Sato, File
April 02, 2015

SAN FRANCISCO (AP) The days of batting average, RBIs, wins and ERA telling the whole story ended a while ago. To get the true picture of how baseball players are performing or will perform in the future takes navigating through an alphabet soup of new-age stats and acronyms.

Some of these statistics look back at what players did. Others are tools to predict future performance, allowing both real general managers and fantasy players a chance to identify under- or overvalued players.

Here's a look at some of them, what they measure and why they're important:

---

WAR: Wins Above Replacement. A single number that tries to encapsulate everything a player does as a hitter, pitcher, fielder and base runner. This allows for comparisons between a slugging first baseman and a slick-fielding shortstop; or five-tool outfielder and elite starting pitcher. The result is how many wins a specific player provided in comparison to a readily available replacement - or a so-called four-A player. Different sites have slightly different calculations but an average starter is worth about two wins, a star around four and an MVP candidate in excess of six.

---

FIP: Fielding Independent Pitching. Tries to measure the aspects of pitching most in control of the pitcher: walks, strikeouts, hit batsmen and home runs. The stat tries to ignore the impact of fielding and luck and is considered a better predictor of future performance than ERA. Players whose FIP is lower than their ERA are often due for rebound seasons, while those with a higher FIP than ERA might be in for regression. The average FIP is the same as the average ERA, to make for simpler comparisons. There is also a cousin of FIP, called xFIP, which measures fly balls instead of homers and assumes a pitcher gives up home runs on a league average amount of fly balls.

---

WPA. Win Probability Added. A different measure of wins based on the context of when events happen. It takes a team's chance of winning a game before and after each plate appearance, with each team starting with a 50 percent chance. The hitter and pitcher each get credit or blame for any change. A homer leading off the game is worth more than one in the eighth inning of a 10-1 game but much less than one in the bottom of the ninth of a 1-1 game. WPA does not measure defense and because it depends on when players get their chances, it is not as predictive of future performance a statistics like WAR or FIP.

---

BABIP: Batting average on balls in play. With growing evidence that pitchers and hitters have little control over what happens once a ball is put into play, BABIP tries to eliminate the effects of luck and fielding on performance. BABIP is a form of batting average that eliminates home runs and strikeouts, while adding sacrifice flies and bunts. Players with a BABIP much below .300 are likely due for an improvement, while those much higher than .300 can be expected to regress.

---

BACON: Batting average on contact. Similar to BABIP, BACON also counts home runs as part of the measurement, only excluding strikeouts from the calculation.

---

Adjusted OPS+: Adjusted on-base plus slugging percentage. Adding on-base and slugging percentage has become an easy tool to better measure the best hitters rather than traditional stats like batting average and RBIs. Adjusted OPS+ also alters the percentage based on how the league as a whole is hitting and a player's home ballpark. This allows for easier comparisons between eras, as well as between hitters who play at hitter-friendly Coors Field compared to cavernous Petco Park.

---

ERA+: Like Adjusted OPS+, ERA+ accounts for how a pitcher performs compared to the league as a whole and factors in home ballpark, once again making comparisons more accurate.

---

UZR: Ultimate Zone Rating. Splits the field into 64 zones and compares how well a given fielder turns balls hit into each zone into outs, compared to the league average.

---

ISO: Isolated Power. Measures extra bases per at-bat, or essentially slugging percentage minus batting average. Shows which players have the most power by taking singles out of slugging percentage.

---

Pitch f/x: A pitch-tracking system created by Sportvision and used in every stadium that tracks the speed, location and trajectory of every pitch. Sportvision also uses Hit f/x to measure what happens to batted balls and Field f/x to measure how much ground players cover and how difficult plays are in the field.

You May Like