"seasons". Bill James reports multi-year and career player statistics in "seasonal notation": per full season played. The selection of Sam Thompson in the 1880s is unusual, with only 3.82 "seasons" played during the decade.
Bill James' Stars of the DecadeNational Association National League 1871-1875 games pos. 1876-1879 seasons Deacon White 259 C Deacon White 3.52 Cal McVey 262 1B Joe Start 3.24 Ross Barnes 266 2B Ross Barnes 2.20 George Wright 245 SS Johnny Peters 3.52 Cap Anson 262 3B Cap Anson 3.14 Andy Leonard 266 LF Charley Jones 3.54 Dave Eggler 260 CF Paul Hines 3.62 Lip Pike 286 RF Jim O'Rourke 3.62 Levi Meyerle 221 U Al Spalding 284 P Tommy Bond 3.77 Candy Cummings 203 P Monte Ward 1.78 1880-1889 seasons pos. 1890-1899 seasons Buck Ewing 5.92 C Chief Zimmer 5.67 Dan Brouthers 7.24 1B Roger Connor 5.95 Hardy Richardson 7.49 2B Cupid Childs 8.21 Jack Glasscock 8.10 SS Hughie Jennings 6.49 Pete Browning 8.14 3B John McGraw 5.51 Harry Stovey 8.22 LF Ed Delahanty 8.25 George Gore 7.32 CF Billy Hamilton 7.67 Sam Thompson 3.82 RF Willie Keeler 5.37 King Kelly 7.92 U Hoss Radbourne 7.55 P Kid Nichols 9.41 Tim Keefe 8.15 P Amos Rusie 8.34 John Clarkson 5.46 P Cy Young 9.92
Positions. Opinions differ concerning whether the outfield is one position or three. Each Bill James CF was a career regular in centerfield. Most of his corner outfielders sometimes played center and some played more in center than in the corners.
Many 19th century players played two to four positions. (Two causes of multi-position play were small rosters and widely shared catching duties.) Anyone who selects players by position enjoys more freedom for the 1870s-80s than for the 1970s-80s. Yet, Bill James took one giant libertine step further by naming Pete Browning at 3b for the 1880s, when he played 52 of 103 games at third in 1884 and 75 of 1055 career games at third. Browning was a full-time outfielder 1885-90 who often played center. On the other hand, naming Cap Anson at 3b for the NA and for NL1876-79 is reasonable; in each half-decade, Anson played more at 3b than anywhere else (c, 1b, of).
Repeat Stars. Three stars represent both the National Association and the National League in the 1870s half-decades: catcher Deacon White, 2b Ross Barnes, and 3b Cap Anson (who played mainly at 1b during his very long career). There is no repeater from the '70s to the '80s or from the '80s to the '90s. Cy Young represents both the 1890s and the 1900s. (See Bill James' All-Stars for the Oughts and Teens.)
Star Teammates. The all-star "teams" include some stars who were teammates for much of the selection period. How may can you name? ;-)
Stars from Two Leagues. Pete Browning (mainly cf) and Harry Stovey (often 1b) played in the American Association for most of its ten years. Tim Keefe was a star for the AA New York Mets, briefly, in a mainly National League career. The other stars named here played in the NL, most wholly so, except for 1890 when most of the best players joined the Players' League.