|Runs in First Inning||Away||Home|
So I submit for the consideration of the forum that it is just random variation at play.
The home team is more likely to be favored to win, so it makes sense that they would score more runs in the first inning.
To me logical thinking would have both teams just about exactly even in scoring for the first and second innings. My best guess as to why the home team has an edge would be ballpark conditions. Just being familier with sun angles and lighting could have an affect. Also, it may take a visiting pitcher a bit longer to get used to pitching mound conditions. Lots of pitchers are very picky about the surface when pitching and it would take visiting pitchers longer to adjust. That being said I never expected such a difference in those stats. Very interesting.