Bob has asked if anyone has rigorously examined the legend of Germany Schaefer stealing first base. The topic has appeared on SABR-L a couple of times.
September 4, 1908 is often cited as a date in which Schaefer pulled the trick with Davy Jones on third base against Cleveland. However, as Lyle Spatz noted in May 2000, Schaefer's club (Detroit) was playing St. Louis that day. They had played Cleveland the previous four days. [It was actually a games series beginning Aug 30.] Lyle found that Schaefer preceded Jones in the lineup on three of those dates & Jones didn't play in the fourth
Ted Turocy noted that he found a case of Schaefer taking first on August 4, 1911 in the first game of a double-header against Washington. In the bottom of the 9th with Clyde Milan on 3rd & 2 outs, Schaefer took first with Milan retired for the third out. Ted didn't have the source in front of him at the time, but he thought it was from the Chicago American.
David Horwich followed up with results of his research. In trying to substantiate the 1908 story as well as other stunts by Schaefer, David noted
he went through every issue of the Sporting News during Schaefer's career & found no mention of the incident. He did find the 1911 play in the 8/10/11 issue of TSN. In that piece, it is stated the Schaefer walked back to first base with the White Sox making no play on him. The White Sox protested that Schaefer should be out and "from something said by one of the umpires, the Sox gathered that Schaefer could be put out while standing on first base, and went after him." Schaefer started for second. Milan broke for home & was thrown out at the plate for the third out.
The Senators then objected, because the play took place while White Sox manager Hugh Duffy was on the field. The umps said time couldn't be called, because Schaefer was technically on the base lines while on first base. The Senators protested the game, but eventually won in 11 innings.