The third game in the contest for the world's championship was played this afternoon before an audience of 6000. The game was fought hard from first to last, but the Chicagos played with even more than their wonted vigor. Clarkson's work in the box was excellent, while Caruthers was not so hard to hit as on yesterday.
-Los Angeles Times, October 21, 1886
The third game of the series between the Chicago champions and the Browns of St. Louis was played this afternoon in the presence of about 4000 people. The weather was favorable, a strong wind blowing directly in favor of the batters. The morning's rain had not affected the condition of the diamond.-Boston Daily, October 21, 1886
And the Globe had the attendance at 5000. This certainly isn't unusual and the first two games also have conflicting attendance data but I find it a bit amusing that I have three sources that list the attendance data for game three of the 1886 series and I have three different numbers.