What is the MLB record for most runs scored in the first inning?
The most runs scored by a single team in the first inning is 16 by the Boston Beaneaters against the Baltimore Orioles in 1894. The most runs scored by both teams in the first inning is 16 held by Boston and Baltimore as described above (Boston 16, Baltimore 0) and the Oakland Athletics and California Angels in a game in 1996 where Oakland scored 13 runs and California scored 3 runs.