The ornamental design for a baseballsafetyjacket, as shown and described.
FIG. 1 is a front elevation view of a baseball safety jacket showing our new design;
FIG. 2 is a rear elevation view thereof;
FIG. 3 is a left side elevation view thereof;
FIG. 4 is a right side elevation view thereof;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a left side isometric view thereof.
The criss-cross pattern is understood to represent fabric and to be repeated uniformly throughout the surface of the claimed design in which it is shown.