1870 National Association

The National Association of Base Ball Players played a two-tier system again this season, allowing both amateur and professional teams. Champions at the time were decided in a manner similar to prize-fighting, the champion defending its claim in a three-game match (though not consecutive games). Atlantic of Brooklyn began the season as champions, lost two games in September to the Mutual Club, which in turn lost the championship to the Chicago White Stockings in a series that featured a bitterly contested and controversial game that ended in a Chicago victory by forfeit.

The entire system for determining a champion had been highly criticized by the sporting media for a number of years, and many newspapers published standings between the top teams for the first time. Standings are retroactive, having been compiled by Marshall Wright in his book The National Association of Base Ball Players (1857-1870) of the teams that were made up entirely of professional players.

Standings

Professional teams

vs. Professional teams only							vs. all teams
Team	G	W	L	T	PCT		Team	G	W	L	T	Pct.
Cincinnati Red Stockings	34	27	6	1	.809		Cincinnati Red Stockings	74	67	6	1	.912
Chicago White Stockings	29	22	7	0	.759		Chicago White Stockings	73	65	8	0	.890
Athletic of Philadelphia	38	26	11	1	.697		Athletic of Philadelphia	77	65	11	1	.851
Mutual (New York)	47	29	15	3	.659		Mutual (New York)	88	68	17	3	.790
Atlantic of Brooklyn	36	20	16	0	.556		Forest City (Rockford)	56	42	13	1	.759
Union (Lansingburgh, NY)	25	11	13	1	.460		Atlantic of Brooklyn	58	41	17	0	..707
Forest City (Rockford)	24	10	13	1	.438		Union (Lansingburgh, NY)	46	30	15	1	.663
Forest City (Cleveland)	24	9	15	0	.375		Forest City (Cleveland)	41	25	16	0	.610
Olympic (Washington, DC)	28	10	18	0	.357		Olympic (Washington, DC)	50	29	21	0	.580
Union (Morrisania, NY)	25	7	18	0	.280		Union (Morrisania, NY)	39	20	19	0	.513
National (Washington, DC)	11	2	9	0	.182		Tri-Mountain (Boston)	13	6	7	0	.462
Eckford of Brooklyn	15	2	12	1	.143		Eckford of Brooklyn	30	13	16	1	.450
Maryland	16	2	14	0	.125		Maryland	27	9	18	0	.333
Tri-Mountain (Boston)	4	0	4	0	.000		Riverside (Portsmouth, Ohio)	9	3	6	0	.333
Riverside (Portsmouth, Ohio)	6	0	6	0	.000		National (Washington, DC)	17	5	12	0	.294

Sources

• Marshall D. Wright: The National Association of Base Ball Players, 1857-1870, McFarland, Jefferson, NC, 2000.