The rec.sport.baseball FAQ

Hits divided by at bats. Has been calculated the same way since its first appearance in 1874, though the definition of "hits" and "at bats" varied until 1888.

Batting Runs

The Linear Weights measure of runs contributed beyond those of a league-average batter or team, such league average defined as zero.

BB

base on balls, or walk.

BBW

USA Today Baseball Weekly.

Boswell, Tom

Baseball writer for the Washington Post.

BR

Batting Runs.

Brock6 System

A complex set of several hundred interlocking formulas, designed to project a player's final career totals on the basis of his performance up to a given point in time. An earlier form was Brock2. The BrockN system(s) will give year-by-year projections, but they tend to vary less than actual performance, so a player will tend to have peak years that are better (and bad years that are worse) than the Brock projections.

C language source code for the Brock2 system is available on the baseball FTP site at ftp.baseball.org.

A raw figure that tells how many of an item have been accumulated, as hits or HR. Contrast with Rate stat.

CS

caught stealing

DA

Defensive Average

Defensive Average

A statistic which expresses a player's fielding performance as number of plays made divided by opportunities. It is a defensive analog of Batting Average or On Base Percentage. It became possible to calculate DA after Project Scoresheet began gathering location data for every batted ball. The field is divided into areas of responsibility, one to each fielder. "Plays made" is "balls turned into outs", "opportunities" is "balls hit into a player's zone of responsibility."

Note that DA doesn't attempt to explain a fielder's performance; a fielder may have a good DA due to superior speed and instincts or due to great positioning skills. DA records a fielder's rate of effectiveness at turning batted balls into outs.

DH

Designated Hitter

DP

Double play

E

error

Earned Run

A run for which the pitcher is held accountable (see Rule 10.18).

Earned Run Average

Calculated as earned runs times nine divided by innings pitched. Introduced as an official stat in the NL in 1912 and in the AL in 1913.

EQA, also EqA

Equivalent Average

EQR, also EqR

Equivalent Runs

Equivalent Average

A statistic developed by Clay Davenport. It is a purely objective measure of a player's offensive performance. It correlates exceptionally well with runs scored per out made; better an batting average, OPS, or runs created. The scale of equivalent average is similar to that for batting average; you should be able to glance at the rating and tell whether it is good or bad.

Equivalent Runs

A statistic developed by Clay Davenport; a companion to EQA. It is the estimated number of runs that this player's stats added to the league. The scale is similar to RBI.

Each misplay which prolongs the time at bat of a batter or which prolongs the life of a runner, or which permits a runner to advance one or more bases (from Rule 10.13). Errors are not defined in the rules as an event (like a base hit), but as a decision of the official scorer.

Favorite Toy

A method used to estimate the chance that a player, at a given point in his career, will reach some specific goal (such as 3000 hits, 400 HR).

Fielding Average

see Fielding Percentage

Fielding Percentage

(PO + A) / (PO + A + E)

Fielding Runs

The Linear Weights measure of runs saved beyond what a league-average player at that position might have saved.

FR

Credited to the batter who drives in the run that gives his team a lead that it never relinquishes. The GWRBI was introduced in 1980, was widely regarded as a bad idea and dropped several years later.

Games Behind

Figured by adding the difference in wins between two teams to the difference in losses and dividing by two.

GB

Games Behind

GDP

Grounded into Double Plays. also GIDP.

GIDP

Grounded Into Double Plays. also GDP.

GWRBI

Hall of Fame. More properly the National Baseball Hall of Fame and Museum, Inc.

Hold

A measure for relief pitchers who are not closers. Credit a hold if a pitcher

enters the game in a Save Situation
records at least one out,
does not finish the game, and
leaves the game with the lead.

HR

Home run

IBB

Intentional Base on Balls

IMO, also IMHO

In My (Humble) Opinion

Inherited Runner

A runner on base when a pitcher enters the game.

Intentional Base on Balls

Recorded by the official scorer when the defensive team clearly intends to walk the batter. Only recorded since 1955.

IP

Isolated Power

Isolated Power

Slugging average minus batting average; this number gives you an idea of how much of a player's offensive output is composed of hits other than singles.

James, Bill

Author of a number of books on baseball, most notably a series of Baseball Abstracts. Did much to popularize "sabermetrics" and generally the approach of studying baseball questions scientifically. James' writing and (especially) statistics don't always hold up to the standards of his best work, but he provided many useful insights and a few worthwhile methods.

K

Strikeout. The symbol appears to come from "strucK out", from the early days of scorekeeping. "S" was already in use for "single".

When scoring, some people use a reverse "K" to differentiate a called strikeout from a swinging strikeout.

LF

Left Field

Linear Regression Model

A common mathematical tool used to derive the value of each element within a data set, and thus prduce formulas that can combine those values. This intimidating-sounding technique has been used by a number of people to create models of team run scoring.

Linear Weights

A linear regression model of team run scoring developed by John Thorn and Pete Palmer.

LOB

Left On Base

McWeekly

USA Today Baseball Weekly. Derived from the usage of "McPaper" to refer to USA Today.

Major League Equivalency

The major league performance that is equivalent to a given performance in the minor leagues. Bill James discovered that by making appropriate adjustments for league and park, you could figure an MLE for a player's minor league performance that is as good for predicting future performance as prior major league data.

Marginal Lineup Value

A statistic developed by David Tate which shows the offensive value of a player compared to a "replacement level" player in the same lineup.

MLB

Major League Baseball

MLE

Major League Equivalency

MLV

Marginal Lineup Value

MVP

Most Valuable Player

OBA

On Base Average. See On Base Percentage

OBP

On Base Percentage

Offensive Production Index

A statistic which shows the overall offensive value of a player.

Offensive Winning Percentage

A Bill James statistic that answers the question: If every player on a team hit the same way that this player hits and the team allowed an average number of runs to score, what would their winning percentage be?

On Base Percentage

Basically, the fraction of a player's plate appeareances that resulted in his reaching base safely. It is defined officially as
(H + BB + HBP) / (AB + BB + HBP + SF)
1-OBP will tell you approximately what fraction of the times a player has gone up to the plate have resulted in outs. It was created by Branch Rickey in the early 1950's in its present form, though it had ninteenth-century predecessors, such as "Reached First Base". Adopted as an official stat in 1984.

Sometimes (more correctly) known as On Base Average.

OPI

Offensive Production Index

OPS

On-base plus slugging (OBP+SLG). A fairly accurate and easily calculated index of a player's rate of offensive production. See also OTS. This statistic combines the two basic offensive skills: getting on base (OBP) and advancing runners (SLG). OPS may also be used for teams. An adjustment which makes OPS more accurate is figuring it as (1.2*OBP+SLG), which compensates for the fact that SLG has a wider range than OBP (i.e., a .500 SLG is common, but only about a half dozen players have ever had .500 OBP's).

OTS

On-base times slugging. A better (than OPS) but harder to calculate measure of a team's rate of offensive production. OTS is not a good method to use for player comparisons, as it overvalues the SLG of high-OBP players.

OWP

Offensive Winning Percentage

PA

Plate Appearance

Palmer, Pete

Co-author (with John Thorn) of Total Baseball and The Hidden Game of Baseball and developer of several statistical methods.

Park Adjustment

Any of a number of methods used to adjust offensive or defensive statistics for park illusions. Most of these methods work by comparing the combinded statistics of a team and its opponents in home games with their performance in away games.

Park Factor

a specific form of park adjustment; it gives a number by which statistics must be divided to compensate for the park effects. (For example, a pitcher with a 4.40 ERA in a park with a 1.10 park factor has a park-adjusted 4.00 ERA.)

Passed Ball

A pitch which the catcher fails to field or hold onto which allows runners to advance, and which (in the judgement of the official scorer) should have been handled with "ordinary effort". See also Wild Pitch.

PB

Passed Ball.

Pitching Runs

A measure of how many runs a pitcher prevented compared to a league average pitcher.

Plate Appearance

AB+BB+HBP+SH+SF+(reached by Defensive Interference)

PO

putout.

PR

Pitching Runs.

Pythagorean Method

A formula developed empirically by Bill James; he discovered that the ratio of a team's wins to its losses is very close to the square of the ratio of the team's runs scored to its runs allowed.

Quality Start

A start in which a pitcher pitches at least six innings and allows no more than three earned runs.

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rec.sport.baseball

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rec.sport.baseball.fantasy

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rec.sport.baseball.analysis

Range Factor

The average number of plays per game successfully made by a fielder. Computed as (PO+A-E)/G

Rate Stat

A figure that shows rate of accumulation of an item, as batting average (hits) or ERA (earned runs). Compare to counting stat.

RBI

Runs Batted In

RF

Right Field

Runs Batted In

The official scorer credits a batter with an RBI for each Run scored as a result of his batted ball unless

the batter grounds into a double play or
the run scored as a direct result of an error.

Runs Created

A statistic created by Bill James as a model of team run scoring. The forumla comes in three flavors, each relying on more information than the previous.

Basic:	RC=	(H+BB)	*	(TB+.26*BB)	/	(AB+BB)
Stolen Base:	RC=	(H+BB-CS)	*	(TB+.25BB+.52SB)	/	(AB+BB)
Complete:	RC=	(H+B+HBP-CS-GDP)	*	(TB+.26*(BB-IBB+HBP)	/	(AB+BB+HBP+SH+SF))

S

Sacrifice (bunt)

Sabermetrics

Derived from SABR; a term coined by Bill James to describe "the search for objective knowledge about baseball". Often fallaciously believed to mean the mindless proliferation of statistics.

SABR

The Society for American Baseball Research. Though the word "sabermetrics" was derived from their name, SABR researches much more than just statistics. In fact, the most popular areas of research in SABR are historical, having to do with correcting (and finding) records of 19th-century players, the Negro Leagues, and all professional baseball games ever played.

Save

Created by Jerry Holtzman of the Chicago Sun-Times, saves were first regularly reported by the Sporting News in 1960. The major leagues adopted it as an official stat in 1969; it took its present form in 1975.

Save Situation

A relief pitcher is in a save situation when

he enters the game with his team in the lead,
is not the winning pitcher of record at the time, and any one of
1. the lead is three runs or less and he pitches at least one inning,
2. the potential tying run is on base, at bat, or on deck, or
3. he pitches three or more innings effectively (in the judgement of the official scorer).

A pitcher MAY NOT create a save situation for himself; whether a save situation exists is determined by the conditions when the pitcher enters the game.

SB

Stolen Base

SDCN

Stat-Drunk Computer Nerd

Secondary Average

The sum of a player's extra bases on hits, walks, and stolen bases expressed as a percentage of at bats. This measures the parts of a player's contribution that don't show up in his batting average.

SF

Sacrifice Fly

SH

Sacrifice Hit, same as Sacrifice (q.v.).

SLG

Slugging Average; sometimes Slugging Percentage.

Slugging Average

A player's total bases divided by at bats. The best measure of a player's ability to advance and/or score runners on base.

Southpaw

a left-handed pitcher. The term comes from the common practice of arranging fields so that home plate is west of the pitcher's mound so that the sun won't be in the batters' eyes as it sets, which orients the pitcher so his left arm is on his south side.

SS

Shortstop

TB

Total Baseball (see section 4).

TBIII

Total Baseball version 3 (see section 4).

Total Average

A method developed by Tom Boswell for expressing a player's overall offensive performance in one number. It is interesting, but flawed.

TP

Triple play

TSN

The Sporting News.

TWG

Telegenic White Guy. A player whose reputation exceeds his ability due to some combination of his being white and a good TV interview. For example, Dan Gladden.

USAT-BW

USA Today Baseball Weekly

W-L, also W/L

Win-loss record (of pitchers or teams, typically).

Wild Pitch

A legally delivered ball that is so high, low, or wide that the catcher cannot stop or catch it with "ordinary effort" (in the judgement of the official scorer) and which allows a runner or runners to advance. A pitch that touches the ground before reaching the plate and is not handled by the catcher should be scored a Wild Pitch if a runner or runners advances. See also Passed Ball.

WP

Wild Pitch

Zone Rating

The percentage of balls fielded by a player in his typical defensive "zone", as measured by STATS, Inc.