This glossary contains definitions of
statistical terms and measures that may be new to the average
baseball fan and the advanced fan alike. The sources of many of the terms
Baseball and Stats, Inc., two of the premier stats services.
ADJUSTED Generally denotes a
statistic that has been altered to reflect normalization to a league average
park factor. Stats that are normalized include Batting Average,
Runs Created, On Base Percentage,
Earned Run Average, OPS and Pitcher
ASSIST Credited to a player who
throws out an opposing runner. Credited to pitchers on strikeouts in some of
baseball's early years.
ASSIST AVERAGE Assists divided by games played. Stat created
by Philadelphia baseball writer Al Wright in 1875.
AT-BATS Charged to a batter when
he engages in a plate appearance, except for when the batter's
appearance results in a base on balls or a sacrifice. Charged on sacrifice hits, 1889-1893; on
sacrifice-fly situations, 1931-1938 and 1940-1953; bases on balls, 1876,
AVERAGE AND OVER Early form of expressing averages for base
hits, runs, and outs. The average of a batter with 23 hits in six games
would be not 3.83 but 35 (an average of 3 with an overage, or remainder,
of 5); borrowed from cricket.
BASES ON BALLS Counted when a
batter takes four balls in a single at-bat and is awarded first base.
Counted as outs for batters in 1876 and as hits for batters in 1887;
awarded for a varying number of errant pitches since 1876, from nine in
that year to the current four (standardized in 1889). (After 1887, the
batter was no longer allowed to specify strike zone as waist to
shoulders or waist to shins.)
BASES ON BALLS PERCENTAGE
Batters' stat - walks per 100 at-bats plus bases on balls.
BASES ON BALLS PER GAME Game
defined as nine innings; league- leading pitchers calculated on basis of
lowest mark; computed as bases on balls times nine, divided by innings.
BATTER'S PARK FACTOR The Park Factor shown in the batters' section of the team statistics
in the Annual Record, Player Register, and Home-Road Statistics.
Above 100 means batters benefited from playing half their games
in a good hitting park. Abbreviated as BPF or, in what are clearly
batters' stats (as in the Player Register) simply as PF. See entry
for Park Factor for the computation.
BATTERY ERRORS In baseball's early years, wild pitches, passed balls, and hit
batsmen were lumped together in the statistical summary of a game
as battery errors and were charged against the fielding percentage
of the pitcher or catcher.
BATTING AVERAGE Calculated as base hits divided by at-bats ever since its first
appearance in print in 1874. In 1876 walks were counted as at-bats,
and in 1887 they were counted as at-bats and as hits.
RUNS The Linear Weights measure for how many runs a
hitter contributes above and beyond what a league average
replacement player would provide. Converts a number of
offensive statistics into their run equivalent, based on
Pete Palmer's 1978 computer simulation of major league games
since 1901. The formula is:
= (.47) 1B + (.78) 2B + 1.09 (3B) + (1.40) HR + .33 (BB+HBP)
- .25 (AB-H) - (0.50) (Outs on base)
WINS Adjusted Batting Runs divided by the number of runs
required to create an additional win beyond average. That average is
defined as a team record of .500 because a league won-lost average must
be .500. Abbreviated as BW. See Runs Per
Total Baseball measure. The difference between a team's actual won-lost record and that
predicted by the total of its Pitching Wins, Batting Wins, Fielding
Wins, and Stolen Base Wins; this measure indicates the extent
to which a team outperformed or underperformed its talent.
EARNED RUN AVERAGE Calculated as earned runs times nine, divided by innings pitched.
For a few years after being introduced as an official stat in
the National League in 1912 and the American League in 1913, runs
aided by stolen bases were not counted as earned. For years
before 1912, ERA has been constructed from raw data, but for some
teams in some seasons, earned runs cannot be identified with perfect
(Adjusted ERA) ERA normalized to the league average
- which is done
by dividing the league average ERA by the individual ERA -
then factoring in home park effect.
EXPECTED WINS Calculated for the team based on its actual runs
scored and allowed, not its predicted runs scored and allowed. A team
that allows exactly as many runs as it scores is predicted to play .500
ball. The equation for expected wins is:
(Runs Scored - Runs Allowed) (Wins + Losses)
-------------------------- + ------------------
Runs Per Win 2
FIELDING AVERAGE Defined as putouts and assists divided by the
total of putouts, assists, and errors. The weakness of this stat is that
it values a player with minimal range but good hands over another player
who may accept many more chances but mishandle a few of these. Abbreviated as FA.
See Range Factor, Total
FIELDING RUNS The Linear Weights measure of runs saved beyond
what a league-average player at that position might have saved, defined
as zero; this stat is calculated to take account of the particular
demands of the different positions.
For second basemen, shortstops, and third basemen, the formula begins
by calculating the league average for the position:
pos .20 (PO + 2A - E + DP) league at position
AVG = ---------------------------------------
lg (PO league total - K league total) where A
= assists, PO =putouts, E = errors, DP = double plays, and K
=strikeouts. Then Total Baseball estimate the number of innings for each player at
each position based upon each player's entire fielding record and his
number of plate appearances.
are doubly weighted because more fielding skill is generally required to
get one than to record a putout.
For catchers, the above formula is modified by removing strikeouts
from their formulas and subtracting not only errors but also passed
balls divided by two. Also incorporated in the catcher's Fielding Runs
is one tenth of the adjusted Pitching Runs for the team, times the
percentage of games behind the plate by that catcher.
For pitchers, the above formula is modified to subtract individual
pitcher strikeouts from the total number of potential outs (otherwise,
exceptional strikeout pitchers like Nolan Ryan or Bob Feller would see
their Fielding Runs artificially depressed). Also, pitchers' chances are
weighted less than infielders' assists because a pitcher's style may
produce fewer ground balls. Thus the formula for pitchers is .10(PO + 2A
- E + DP), whereas for second basemen, shortstops, and third basemen it
is .20(PO + 2A - E + DP).
For first basemen, because putouts and double plays require so little
skill in all but the odd case, these plays are eliminated, leaving only
.20(2A E) in the numerator.
For outfielders, the formula becomes .20(PO + 4A - E + 2DP).
weighting for assists is boosted here because a good outfielder can
prevent runs through the threat of assists that are never made; for
them, unlike infielders, the assist is essentially an elective play,
like the stolen base. Outfielders' Fielding Runs were subject to some
degree of error because outfielders sometimes switch fields within a
game or season (Babe Ruth, for example, was positioned in the field that
required the lesser range--right field in Yankee Stadium, left field in
most road parks). Also, short distances to left-or right-field walls in
some parks tend to depress putout totals.
Since the third edition of Total Baseball, however,
researchers there have obtained breakouts of all outfielders' games in left,
center, and right fields. Center fielders now have higher ratings than
they did in the first and second editions. Abbreviated as FR.
Example: Ozzie Smith in 1978.
Begin by looking at the league average
- NL shortstops in 1978, had 3,191 PO, 6,199 A, 332 E, and 1,105
DP. The league as a whole had 52,000 PO and 9905 K. The AVG(POS,LG)
The Wiz in '78 played 1,327 of the
1,433 2/3 innings played by the Padres (0.926 of the total). Ozzie
had 264 PO, 548 A, 25 E, and 98 DP. The Padres had 4,301 putouts
as a team and fanned 744 hitters. Ozzie's FR are:
FIELDING WINS Fielding Runs divided by the number of runs
required to create an additional win beyond average. That average is
defined as a team record of .500 because a league won-lost average must
be .500. Abbreviated as FW. See Runs Per
GAMES BEHIND Figured by adding the difference in wins between
a trailing team and the leader to the difference in losses, and dividing
by two. Thus a team that is three games behind may trail by three in the
win column and three in the loss column, or four and two, or any other
combination of wins and losses totaling six. Abbreviated as GB.
GAME-WINNING RUN BATTED IN Credited to the batter who drives
in a run that gives his club a lead that it never relinquishes, no
matter when that run is driven in nor what the final score is.
Introduced in 1980 as an official stat and later disowned, the GWRBI is
not recorded in this volume.
GROUNDED INTO DOUBLE PLAY Kept officially since 1993 in the NL
and 1939 in the AL (though the NL data of 1933-38 made no distinction
between lined-into double plays and grounded-into double plays, and the
AL data of 1939 was not published). This stat tends to be overvalued by
the general public as an indicator of rally-killing ineptitude. Instead,
it is largely a function of high totals of at-bats, which tend to be
accumulated by the game's best players, not its worst. Abbreviated as
HANDS OUT The original 1840s scoring term for batters
producing outs either at the plate or on the bases. On a force out, the
runner retired on the bases would be charged with a hand out, not the
batter. Also called Hands Lost, and abbreviated as HO or HL.
HIT BY PITCH A batter struck by a pitched ball was not awarded
first base until 1884 in the American Association and 1887 in the
National League. Reconstruction of stats for batters and pitchers in the
years 1897-1908 has been accomplished. Abbreviated as HBP.
HITS Bases on balls originally counted as hits in 1887, but
are recorded in this volume as neither hits nor at-bats.
HOME RUN FACTOR A measure of the home runs hit in a given
ballpark, with 100 representing the average home park and the highest
figure above that representing the best home-run park. Computed in the
same manner as Home Run Batter Rating (see above). Abbreviated as HRF.
HOME RUN PERCENTAGE Home runs per 100 at-bats.
HOME RUN PITCHER RATING A measure of a team's ability to
prevent home runs, taking into account the Home Run Factor (see above)
of the park and the team's not having to face its own batters. The
average mark is represented as 100, and the lowest figure beneath that
indicates the best.
HOME RUNS When is a home run not a home run?
Before 1920, not
if it came with men on base in the ultimate inning and created a margin
of victory greater than one run. A ruling of the Special Baseball
Records Committee in 1969 reversed its earlier decision that had made
home runs of 37 disputed final-inning, game-winning base hits. In
accordance with the practice of the day, such a hit, even if it sailed
out of the park, would be credited with only as many bases as necessary
to plate the winning run. Thus Babe Ruth's "715th home run," hit on July
8, 1918, to win a game against Cleveland, remained a triple, and Jimmy
Collins and Sherry Magee were each deprived of two home runs.
INNINGS PITCHED Official baseball practice was, until 1982, to
round off fractional innings for individuals to the next highest inning.
Since then fractional innings have been kept for individuals and teams.
In this volume fractional innings are supplied for all individuals and
all teams in all years. Those men who took a turn on the mound but
failed to retire a batter are credited with no innings pitched and, if
they allowed a runner or runners to score, an ERA of infinity.
INTENTIONAL BASES ON BALLS Recorded only since 1955.
ISOLATED POWER Total bases minus hits, divided by at-bats; in
other words, Slugging Average minus Batting Average. Appears to have
been created by Allan Roth and Branch Rickey in the 1950s.
LEAGUE-AVERAGE REPLACEMENT PLAYER That model player who
performs at precisely the league average, creating a baseline against
which to measure others.
ON BASE PERCENTAGE Created by Roth and Rickey in its current
form - hits plus walks plus hit by pitch, divided by at-bats plus walks
plus hit by pitch - in the early 1950s, although there were
nineteenth-century forebears such as "Reached First Base." When OBP, as
it is abbreviated, was adopted as an official stat in 1984, the
denominator was expanded to include sacrifice flies. The effect is to
penalize a batter in his on base percentage by giving him a plate
appearance while at the same time crediting him in his batting average
by deleting the plate appearance. In this book we calculate OBP without
considering sacrifice flies, which in any event are calculable on a
continuing basis only since 1954.
ON BASE PLUS SLUGGING A simple
but elegant measure of batting prowess, in that the weaknesses of
one-half of the formulation, On Base Percentage, are countered by the
strengths of the other, Slugging Average, and vice versa.
When adjusted for home park and
normalized to league average, the calculation is modified
slightly to create a baseline of 100 for a league-average performance.
For PRO+, the calculation is
Player On Base Pct. Player Slugging Avg.
-------------------- + -------------------- - 1
League On Base Pct. League Slugging Avg. This produces a
figure with a decimal point - an above-average figure, like 1.46, or a
below-average figure, like 0.82.
abbreviated as OPS, though it is abbreviated by Total Baseball as PRO,
and abbreviated as PRO+ when normalized to a league average and adjusted
for Park Factor.
OPPONENTS' BATTING AVERAGE Hits allowed divided by at-bats
allowed (or, if at-bats allowed is unknown, then at-bats equals hits
plus inning times "K," where "K" is the league average of at-bats minus
hits, all over innings). Abbreviated by Total Baseball as OAV.
OPPONENTS' ON BASE PERCENTAGE For years before 1908 in the
American League and 1903 in the National League, the number of batters
facing a pitcher has been constructed from the available raw data. We
have subtracted league base hits from league at-bats, divided by league
innings pitched, multiplied by the pitcher's innings, and added his hits
and walks allowed and hit by pitch and sacrifices, if available. Abbreviated
by Total Baseball as OOB.
OUTS Until 1883, included catching a ball on one bounce in
foul ground. Not credited after three strikes in 1887, when the rule was
"four strikes and yer out" - as it was, in fact, from 1871-1881, when
batters commonly received "warning pitches" rather than called
OUTS PER GAME The 1860s successor to Hands Out (see above), it
joined with Runs Per Game to form the batting record before the rise of
professional league play.
PARK FACTOR Calculated separately for batters and pitchers.
Above 100 signifies a park favorable to hitters; below 100 signifies a
park favorable to pitchers.
STATS uses a five-year average Park Factor for
players and teams unless they change home parks. They first compute a
Park Index, which is the ratio of runs scored (both by and against a
particular team) in the home ballpark to the runs scored (by and
against) in visiting ballparks.
Once an index has been created, adjustments are made to reflect the fact
that a team plays fewer innings at home than on the road - the home team
doesn't bat in the bottom of the ninth if it is leading - and to reflect
the fact that the team being rated doesn't get to play road games in its
own park. For example, the Colorado Rockies play in Coors Field, a
ballpark which boosts run production. Their Park Index is going to be
very high, because far more runs are scored at home than on the road.
However, every other team in the league gets to play some road games at
Coors, benefiting from it's friendliness to hitters; the Rockies must
play every road game away from Coors, and that dilutes their Park
A Total Baseball measure devised to quantify how many runs a pitcher
saves for his team relative to a league average pitcher. The formula is:
(league ERA - pitcher's ERA) x (innings pitched by pitcher)
Pitcher Runs = ------------------------------
In this manner,
the value of a pitcher in terms of runs prevented can be measured.
PUTOUT AVERAGE Putouts divided by games played; a stat created
by Philadelphia baseball writer Al Wright in 1875.
QUALITY START A game started in which a pitcher lasts for six
innings or more and allows three runs or less.
RATIO Hits plus walks plus hit batsmen allowed per nine
innings. Abbreviated as RAT.
RUN BATTED IN Though widely regarded as a good measure of a
batter's overall productivity and value to his team, the RBI is
extremely situation-dependent, denying equal access to opportunity on
the basis of a player's team, slot in the batting order, and
particularly the men surrounding him in the batting order.
RANGE FACTOR A measure of
defense - the average number of defensives plays a player makes in a
nine-inning game. Comparing this to the league range factor
gives you an idea of how a defensive replacement would fare.
RUNS CREATED Bill James's formulation for run contribution
from a variety of batting and baserunning events. Many different
formulas are used, depending upon data available. In its basic
expression, the formula is:
(Hits + Walks) (Total Bases)
At-Bats + Walks
The essence of this formulation
is that the ability to get on base and the ability to push baserunners
around fairly describes offensive ability. James later refined the
formula with a "stolen base version":
(Hits+Walks-Caught Stealing)(Total Bases +.55 X Stolen Bases)
At-Bats + Walks
In it's current version, the formula is:
factor: Hits + Walks + HBP - GIDP - CS
factor: Total Bases + ((Walks + HBP - Intentional Walks) * .24) +
(SB * .62)
+ ((SH + SF) * 0.5) - (SO * .03)
factor: AB + Walks + HBP +SH + SF
Runs Created = (A + B) / C
RUN FACTOR A measure of the run scoring in a given ballpark
compared to other ballparks, with 100 representing the average home park
and the highest figure above that representing the best hitters' park.
Abbreviated as RF, it is computed on the basis of comparing runs scored
and allowed per inning at home and on the road. Innings are estimated
from the number of games and games won, allowing for the home team not
batting in the final inning of a game in which it leads. The resulting
Run Factor is then compared to the league average.
RUNS PER WIN
A measure of how many additional runs it takes to create an
additional win. Although the number varies from year to year, Pete
Palmer has devised a rule of thumb that states: for each additional ten
runs scored, one win results. More specifically, wins are
increased in proportion to the square root of runs scored - so
runs-per-win is roughly the square root of the number of runs scored per
game. Thus, the 10:1 Palmer rule of thumb is fine as long as the
runs scored in a game are around 10.
RBI OPPORTUNITIES An official American League stat for the
first three weeks of 1918, until the league saw how much work it
involved and scrapped it. Still a good idea, sort of, and the folks at
the Elias Sports Bureau have tracked this type of "situational stat"
RELATIVE BATTING AVERAGE Pioneered by David Shoebotham in a
Baseball Research Journal article in 1976, this was the first
traditional stat normalized to league average so as to permit cross-era
comparison. Most folks who have employed this measure simply divide
individual batting average by league batting average. Shoebotham's
original computation was more precise:
player's hits / player's AB
RBA = ---------------------------------------
(league hits - player's hits) / (league AB - player's AB)
In this manner a player's own
performance would not be compared with itself.
SACRIFICE FLY First recognized as an event in 1908 but
indistinguishable in the official records from sacrifice hits until
1954. There has been much flip-flopping since 1930 on whether to credit
the sacrifice flier with an at-bat or an RBI or whether a fly ball that
advances a runner to a base other than home plate also should exempt a
man from an at-bat.
SACRIFICE HITS Invented in the 1860s, recorded since 1889;
sacrificer charged with an at-bat until 1894. Sabermetricians frown on
the strategy because all the studies show that the trading of an out for
a base advanced is a losing strategy - lowering the run expectations of
the team that attempts it - in all but the most unusual of cases ... even if the sacrifice "succeeds."
SACRIFICE HITS ALLOWED Computed officially in the National
League since 1913 but not published until 1916, and kept in the American
League since 1921 but not published until 1922; what it signified about
anything is unclear.
SAVE Created by Jerome Holtzman of the Chicago Sun-Times, the
save began to be reported by The Sporting News on a regular basis in
1960. The major leagues adopted the save in 1969, at which time it was
credited to a reliever who finished a game that his team won. In 1973
the save was redefined so that a reliever had not only to finish the
game but also to find the potential tying or winning run on base or at
the plate, or, alternately, to pitch the final three innings of a
victorious contest. In 1975 the rule was liberalized to include a
reliever's appearance of one inning or more in which he protects a lead
of three runs or less; or he enters the game with the tying or winning
run on base, at bat, or on deck; or he pitches three innings to the
SHUTOUTS On an individual basis, credited only to pitchers of
complete-game scoreless victories; former practice was to credit
combined shutouts to the starting pitcher if he had pitched most of the
way. Abbreviated as SH.
SITUATIONAL STATISTICS How does a batter perform with the
bases loaded? At night? On artificial turf? With no one on base? After
the seventh inning when his team is tied or trails? The specialty of
Baseball Workshop, Stats, Inc., and the Elias Sports Bureau.
SLUGGING AVERAGE Total bases divided by at-bats; combines
nicely with On Base Percentage to create a simple but elegant measure of
performance. Usually abbreviated as SLG.
STARTER RUNS Identical to Pitching Runs
confined to starting pitchers, defined as those who average more than
three innings per appearance. Abbreviated by Total Baseball as SR.
STOLEN BASE AVERAGE Stolen bases divided by attempts; its
computation is dependent upon the availability of caught-stealing
numbers. Abbreviated by Total Baseball as SBA.
STOLEN BASE RUNS For teams, the Linear Weights measure of runs
contributed beyond what a league-average basestealing team might have
gained, defined as zero; for individuals, Stolen Base Runs are
calculated on the basis of the 66.7 percent success rate that
sabermetric studies have shown to be the break-even point for producing
runs beyond the average. Availability dependent upon caught stealing
data as with Stolen Base Average. The formula is simple:
.30(Stolen Bases) - .60(Caught Stealing).
A man who steals two bases
in three attempts is merely spinning his wheels in terms of value to his
team, and even a man who succeeds at an 80 percent clip will have to
steal a lot of bases - about 65 - to create just one win beyond average.
Abbreviated by Total Baseball as SBR.
STOLEN BASE WINS Stolen Base Runs divided by the number of
runs required to create an additional win beyond average. Those runs are
generally around around 10 - historically in the range of 9-11. Abbreviated as SBW.
See Runs Per Win.
STOLEN BASES Credited to a
player who moves from one base to the next without the benefit of the
player at bat making contact with the baseball. Recorded since 1886, but until 1898 steals are
thought to have included a variety of daring baserunning exploits, such
as going from first to third on a single or advancing an extra base on
an out. Abbreviated as SB.
STRIKEOUTS Credited to a
pitcher who makes an out on strikes. Varying rules concerning the strike zone, the foul
strike, and the warning pitch - not to mention the fourth strike of 1887
- all contribute to making the cross-era comparison of strikeout
accomplishments a very sticky business. Abbreviated as SO.
STRIKEOUT PERCENTAGE A batters' stat: fewest strikeouts per
100 at bats.
TOTAL AVERAGE Tom Boswell's formulation for offensive
contribution from a variety of batting and baserunning events. The concept of the numerator is
bases gained, that of the denominator is outs made:
(Total Bases + Steals + Walks + HBP - Caught Stealing)
(At-Bats - Hits + Caught Stealing + GIDP)
Abbreviated as TA.
See Base-Out Percentage.
TOTAL BASEBALL RANKING The "MVP" of statistics, this ranks
pitchers and position players by their total wins contributed in all
their endeavors, revealing the most valuable performers in a given year.
Abbreviated as TBR, it is not a computed stat but a sorting of players
and pitchers by, respectively, the sum of their Total Batter Rating and
Total Pitcher Index.
TOTAL BASES AVERAGE Henry Chadwick's measure that divided
total bases by games played; a forerunner of the Slugging Average.
TOTAL BASES RUN A silly stat of one year's duration, 1880,
this was sort of an RBI in reverse, from the runner's perspective. Also
called "Bases Touched," it was nothing more than that and signified
nothing about individual talent. Trivia: the National League's leader in
1880 was Abner Dalrymple, with 501 bases touched.
TOTAL CHANCES Putouts plus assists plus errors; in other
words, total chances offered, not total chances accepted.
TOTAL PITCHER INDEX The sum of a pitcher's
Runs - expressed as Ranking Runs, employing the same formula used to compute
Relief Ranking Runs - Batting Runs (in the AL since 1973, zero), and
Fielding Runs, all divided by the Runs Per Win factor for that year
(generally around 10, historically in the 911 range); abbreviated as
TPI. See Runs Per Win, Relief Ranking.
TOTAL PLAYER RATING The sum of a player's
Adjusted Batting Runs, Fielding
Runs, and Base Stealing Runs, minus his positional
adjustment, all divided by the Runs Per Win factor for that year
(generally around 10, historically in the 9-11 range). See Runs Per
TRIPLE CROWN Long regarded as consisting of batting average,
home runs, and RBI, but was not always so. In the early years of this
century, newspapers spoke of Ty Cobb shooting for the "triple
batting average, runs, and hits.
WIN Credited to a pitcher who is
on the mound when his team scores the winning run.
PERCENTAGE Computed as wins over decisions.