First base line
The Mets' dugout at Citi Field is on the first base side.
Third base side
The Royals' home dugout is on the first base side.
The visitor's dugout is located on the First Base side of the diamond.
The Atlanta Braves dugout is on the 1st base side of the field.
The first base side of the field.
The dugout on the first base side is always home no matter what league you are in.
Because when they form it, they usually have it dug out of the ground on the side of the baseball field, hence the term "Dugout".
If your standing on home plate looking towards the pitchers mound, the Red Sox dugout is on the right side.
The home dugout is the first base dugout.