tBG (total Bases Generated)

tBG and its family of baseball stats are developed and maintained by Mike Walsh and Tom Lewis.

To contact us, send email to tbg@totalbasesgen.com.

tBG is a new baseball stat (and a family of related stats) that measures total offensive productivity by scoring the bases generated in each plate appearance as follows:

Bases earned from hits are credited to the batter.

Bases earned from all other types of offensive plays are counted, such as walks, hit by pitch, errors, etc. That is, "all" bases generated during "all" plate appearances are counted. Thus, the name "total" Bases Generated.

Bases are also credited to batters for bases gained by runners on base as a result of a batted ball, walk, hit by pitch, error, etc.

Bases lost are debited for outcomes such as double and triple plays and when runners are thrown out at a base (when not forced).

Base runners are credited and debited for bases gained and lost on running plays, such as steals, pick offs, balks, interference, pass balls, and throwing errors.

The bases generated for each play are totaled for each player for each year and divided by plate appearances to determine a player’s tBGPA (total Bases Generated per Plate Appearance) for each year. Career and team values are also calculated, and tBG stats are adjusted for park factor. tBGR (total Bases Generated as a Runner) and tBSI (total Bases Surrendered per Inning) stats are also derived from the same data.

The play data in the tBG database was obtained free of charge from and is copyrighted by Retrosheet.
Interested parties may contact Retrosheet at 20 Sunset Rd., Newark, DE 19711.

Data from the Lahman database was also used in this project.

tBG Reports

These reports appear in GoogleDocs and permit filtering and sorting.
Years covered: 1914-2023 (including the Federal League for 1914 and 1915).

Overall Team Performance

total Team Performance - This report combines normalized tBG+ and tBS+ team values for an overall team performance value we call "totalPerf". Can this tell us which team was the greatest ever? (This also includes many other team metrics, so maximize the report window to see all columns.)

Batting Reports

total Bases Generated (tBG) Player Year - tBG totals for each player per year. Qualifying criteria is the same used by MLB -- 3.1 plate appearance per game, which comes to 502 plate appearances for seasons with 162 games. The required PAs are lower for years with fewer games: 1972, 1981, 1994, 1995, and 2020.
total Bases Generated (tBG) Player Career - tBG career totals per player.
tBG Team Year - tBG totals for each team and year. This report identifies the teams that produced the most offense in a season.
tBG Player By Team - The bases generated by each player by team for career. Only those bases generated for the team are counted in an entry. If a player played for multiple teams, he will have a row for each team. Filter by team, and you can see who generated the most bases for your team.
Cumulative Team tBG - Which team produced the most total offense? That depends.
Most tBG by a Player in a Game - The players who produced the most offense in a single game.
Most tBG by a Team in a Game - Which team produced the most offense in a single game?
Most tBG by Both Teams in a Game - Which single game produced the most offense?
Fewest tBG by Both Teams in a Game - Which game had the least amount of offense?

Pitching Reports

Total bases surrendered by each pitcher by year, career, inning, and by team year. Starters, relievers, and closers appear in different reports. See the title pages of each report for the criteria for each report.

tBS Starters Year tBS Relievers Year tBS Closers Year	tBS Starters Career tBS Relievers Career tBS Closers Career
tBS Team Year Most Bases Surrendered by a Pitcher in a Game - The pitchers who gave up the most bases in a single game. Pitcher 1-Inning Meltdown Report - Most bases surrendered by a pitcher in a single inning.

Base Running Reports

Sort by the tBGR columns in either direction to identify the best and worst base runners back to 1914. Note: The numbers on these reports do not include all years for players who started their careers before 1914, like Ty Cobb, who started generating/losing bases as a base runner in 1905.

tBGR Player Year - total bases generated as a base runner (tBGR) for each player per year.
tBGR Player Career - tBG base running totals per player career.
tBGR Team Year - Identifies the best and worst base running teams in MLB history.
Most Bases Gained as a Base Runner in a Single Game - Highest tBGR in a single game--BEST game running the bases since 1914.
Most Bases Lost as a Base Runner in a Single Game - Lowest tBGR in a single game--WORST game running the bases since 1914.

Glossary

Acronyms that appear on the reports.

Batting Stats

tBG: total Bases Generated for a year or career (depending on the report).
tBGp: total Bases Generated, adjusted for park factor.
tBGPA: total Bases Generated per Plate Appearance.
tBGPAp: total Bases Generated per Plate Appearance, adjusted for park factor.
tBG+: tBGPAp normalized. Value for a player or team compared to the league average for that year. 100 is average, and above or below 100 indicates that the player was above or below the tBGPAp average.
PossBG: Max # of bases that can be generated for a plate appearance (min of 4 to max of 10). These are totaled and presented with the various tBG stats for a year or career.
PossBG%: Percentage of PossBG that the player actually generated.

Base Running Stats

tBGR: total Bases Generated as a base runner. Includes bases gained and lost as a base runner. These are bases not attributed to the batter but, instead, attributed to a base runner. A subset of tBG.
+tBGR: Bases gained by a player as a base runner.
-tBGR: Bases lost by a player as a base runner.

Pitching Stats

tBS: total Bases Surrendered.
tBSp: total Bases Surrendered, adjusted for park factor.
tBSI: total Bases Surrendered per Inning Pitched.
tBSIp: total Bases Surrendered per Inning Pitched, adjusted for park factor.
tBS+: tBSIp normalized. Value for a player or team is compared to the league average for that year. Like other normalized stats (such as OPS+ and wRC+), 100 is average. A value of 105 means that the player is 5% above average.