Team Runs Earned Runs %ER %UER
StL 222 78 35.1 64.9
Chi 257 116 45.1 54.9
Hart 261 116 44.4 55.6
Bost 450 176 39.1 60.9
Lville 334 121 36.2 63.8
NY 412 173 42.0 58.0
Phi 534 197 36.9 63.1
Cin 575 238 41.4 58.6
NL Total 3045 1215 39.9 60.01
Pretty simple stuff. I went to the pitching totals and took the total numbers of runs allowed by each club and the total number of earned runs allowed. I divided earned runs by total runs scored and multiplied by 100 to get the percentage of earned runs each club allowed. Then I subtracted the percentage of earned runs from one hundred to get each club's percentage of unearned runs allowed. I added up the club totals, multiplied, divided and subtracted and got the percentage of unearned runs allowed in the NL in 1876. Feel free to correct me if the math or methodology is wrong.
Sixty percent of runs scored in the NL in 1876 were unearned. By way of comparison, 8.4% of runs allowed by the 2009 St. Louis Cardinals were unearned (and they were not a great defensive club). For some reason, I had that 60% number in mind when I started doing this so I'm thinking that someone, somewhere already did this exercise and came up with the same number. I'm not all that bright and I don't believe in coincidences so I must have read about this somewhere.
Applying this information to our investigation of the 1876 Brown Stockings brings up an interesting question. Were the Brown Stockings the best defensive club in the League? They certainly had the reputation of being an outstanding defensive club and the St. Louis Globe-Democrat stressed the importance of defense to their success. Looking at the raw numbers, the Browns lead the League in fewest runs allowed, fewest earned runs allowed, fewest errors and highest fielding percentage and that would support the idea that they played good defense. However, the 1876 Brown Stockings led the League in percentage of unearned runs allowed and that tells me that their defensive reputation may be bit exaggerated.
The Browns were a good defensive club and I wouldn't argue otherwise but I can't say that it's obvious that they were the best defensive club in the League. They committed fewer errors and had a better fielding percentage than Chicago or Hartford but gave up a higher percentage of unearned runs than either club. Based on that (and comparing their team defensive stats) I think that you could make an argument that Chicago and Hartford were every bit as good defensively as St. Louis.
On the other hand, the Brown Stockings scored substantially fewer runs than either Chicago or Hartford and there is no doubt that their success was built around pitching and defense. Maybe we should be giving more credit for the club's success to George Washington Bradley. The Browns, with Bradley on the mound, just didn't give up many earned runs. To score against Bradley, you had to hope that the defense behind him was booting the ball around. That may be why I was so amazed at the number of unearned runs the club was giving up in April and May of 1876. Not only were they giving up a lot of unearned runs but most of the runs that they gave up were unearned. The unearned runs simply stand out more in that context.