Which pitcher has given up the most runs in a single inning? Which pitcher holds the record for a single game?

The record for runs allowed in a single inning is 16, by Tony Mullane in the first inning on June 18, 1894. The post-1900 record is 13, by Lefty O’Doul. Dave Rowe set the mark for runs allowed in a game with 35 on July 24, 1882, and Al Travers owns the post-1900 record with 24.