Lefty O' the Big League by Burt L. Standish

Lefty went to his room rather early that night, but not to bed. The discovery of the terrible mistake he had made regarding Elgin bewildered him at first, and then made him feel as if he wanted to get away by himself to think it all over.

For three years he had felt absolutely certain of Bert Elgin's responsibility for that theft at Princeton. He had felt the scorn and contempt for his college mate which any decent man would naturally feel for a person guilty of what Elgin had done. He had, moreover, from the very first, never hesitated to show those feelings. Now it would seem that he had been totally in the wrong.