Glossary - Seamheads Negro Leagues Database

Glossary

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Player Graphs

Batting Career Graph

This uses a player's ten best offensive seasons, determined by offensive Win Shares. For players with less than ten career seasons, all of their seasons are included.

Rate stats are compared to the league averages (which are adjusted for the player's ballpark). For example, a player with a .290 batting average with a league average of .260 would be 11.5% better than league average. This number is then compared to the x players with the most plate appearances (where x = # of teams that year multiplied by 8), to find the percentile. This is done for all ten seasons, with the mean percentile (weighted on plate appearances) being the final value that is displayed on the graph.


Statistics Used


  • wOBA (Weighted On-Base Average)
  • BA (Batting Average)
  • OBP (On-Base Percentage)
  • SLG (Slugging Percentage)
  • IsoP (Isolated Power)
  • HR% (Homerun Percentage)
  • BB% (Walk Percentage)
  • K% (Strikeout Percentage)
  • BB/K (Walks per Strikeout)
  • SB (Stolen Bases per Opportunity)

As a general rule of thumb, high percentiles are good and low percentiles are bad. A batter in the 98th percentile of strikeout percentage is better than 98% of the league at avoiding strikeouts.


This uses a player's ten best pitching seasons, determined by pitching Win Shares. For players with less than ten career seasons, all of their seasons are included.

Rate stats are compared to the league averages (which are adjusted for the player's ballpark). For example, a player with a 2.50 ERA with a league average of 3.50 would be 40% (3.50 / 2.50) better than league average. This number is then compared to the x players in the league with the most batters faced, to find the percentile. This is done for all ten seasons, with the mean percentile (weighted on batters faced) being the final value that is displayed on the graph.

For starting pitchers


1970-Pres, x = 5 * # of teams that year
1901-1969, x = 4 * # of teams that year
1890-1900, x = 3 * # of teams that year
1880-1889, x = 2.5 * # of teams that year
1871-1879, x = 1.5 * # of teams that year

For relief pitchers


1970-Pres, x = 4 * # of teams that year
1950-1969, x = 3 * # of teams that year
1871-1949, relief pitchers are included with starting pitchers


Statistics Used


  • R/9 (Runs allowed per 9 innings, with a fielding adjustment)
  • FIP (Fielding Independent Pitching)
  • WHIP (Walks & Hits per innings)
  • BA (Opponent's batting average)
  • HR% (Homeruns allowed percentage)
  • BB% (Walks allowed percentage)
  • K% (Strikeout percentage)
  • K/BB (Strikeouts per walk)
  • CG% (Complete game percentage)
  • BIP% (Balls in play percentage)
  • Hold (Stolen Bases allowed per opportunity)

As a general rule of thumb, high percentiles are good and low percentiles are bad. A pitcher in the 87th percentile of walks allowed percentage is better than 87% of the league at avoiding walks.



Fielding Career Graph

This uses a player's ten best fielding seasons, determined by fielding Win Shares. For players with less than ten career seasons, all of their seasons are included. To qualify for a percentile rating, a player needs at least 200 career games at that position

Using Defensive Regression Analysis, this graph looks at runs saved per 1000 innings and compares this rate to the x players at that position with the most innings (where x = # of teams that season), to find the percentile. This is done for all ten seasons, with the mean percentile (weighted on innings) being the final value that is displayed on the graph.


If you have any questions regarding Negro Leagues statistical or biographical data, please contact gary@seamheads.com. For any other questions/comments/suggestions, please contact the web developer at BaseballGauge@gmail.com.

All biographical data, copyright 2011-2018 Gary Ashwill.

Playing statistics for 1887-1922 and 1926-1938, as well as all Cuban League games (1902-1928) and Negro League vs. Major League games (1887-1944), copyright 2011-2018 Gary Ashwill.

Playing statistics for 1923 (except Negro League vs. Major League games), copyright 2011-2018 Patrick Rock.

Playing statistics for 1933 and 1943, copyright 2013-2018 Scott Simkus.

Playing statistics for 1924-1925, 1939-1942, and 1944-1946 Negro Leagues (not including Cuban League and Negro League vs. Major League games), copyright 2011-2018 Larry Lester, Wayne Stivers, Gary Ashwill.


Defensive Regression Analysis data used here was obtained with permission from Michael Humphreys, author of Wizardry

Win Shares are calculated using the formula in the book Win Shares by Bill James