tBG and its family of baseball stats are developed and maintained by Mike Walsh and Tom Lewis.
Email: totalbasesgenerated@gmail.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 base runners 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, doubled off, balks, pass balls, and throwing errors.
The bases generated for each play are totaled for each player for each season and divided by plate appearances to determine a player’s tBGPA (total Bases Generated per Plate Appearance) for each season. 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.
So far we have scored over 16 million plays back to 1910, and we'll add more years to our database as that data becomes available.
Offense = Bases: An Explanation of tBG
Watch the presentation Mike Walsh gave about tBG
at the Babe Ruth Museum and Birthplace on Oct. 10, 2025.Recent updates:
Xtra Bases: We recently developed an Xtra Bases base running stat, with three new reports. We also added XtraB to tBGR on our base running reports
for a new base running total called XtBGR, one of the most comprehensive base running stats available. XtBGR counts 23 plays.The database and all reports have been updated with two new years, 1910 and 2025.
Upcoming Events:
Mike will give a presentation about the 1966 Phillies and a game he attended that year at Connie Mack stadium on Thursday, March 12, 1 pm at the Creutzberg Center in Radnor, PA.
Sponsored by Main Line School Night. Click the link to register.Presentation about tBG via Zoom on Monday, April 13, 7 pm for the Vermont and Maine SABR chapters. Everyone is invited.
tBG ReportsThese reports appear in GoogleDocs and permit filtering
and sorting. Overall Team Performance
Batting Reports
Pitching Reportstotal Bases Surrendered (tBS) by each pitcher by season, career, inning, and by team season. Starters, relievers, and closers appear in different reports. See the title pages of each report for the qualifying criteria.
Base Running Reports
| Articles:The Player Who Was Caught Stealing Home Twice in the Same Inning The September Call-Up Who, For One Month, Played like a Baseball God The Three Four-Homer Games of 2025 Walker Cooper's and Josh Hamilton's historic games Two of the Greatest Base Running Performances in MLB history The Rangers Historic Thrashing of the Orioles on Aug. 22, 2007, at Camden Yards Joe Judge (9/21/16): The Worst Base Running Performance in MLB History? A
Mythical Willie Mays Triple, a Matinee Hero, and Some Bored Cub Scouts:
July 16, 1966, at Connie Mack Stadium, Giants vs. Phillies Phils Choked in 2003 and 2004 but Nothing Compared to 1964 Phlegm of Dreams: Those Salivatin’, Expectoratin’ Boys of Summer GlossaryAcronyms that appear in the tBG reports. Batting Stats
Base Running Stats
Pitching Stats
|
|||||
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 is also used in this project.