The ornamental design for a "retractable tethered ball baseball practice device", as shown and described.
FIG. 1 is a top, front and right side perspective view of a retractable
tethered ball baseball practice device showing my new design, the top,
rear and right side perspective view being a mirror image;
FIG. 2 is a left side view thereof;
FIG. 3 is an enlarged and fragmented top plan view thereof; and,
FIG. 4 is an enlarged and fragmented bottom plan view thereof.
FIGS. 3 and 4 are shown fragmented for ease of illustration.