The ornamental design for a billiardstroketrainingaid, as shown and described.
FIG. 1 is a top front right perspective view of a billiard stroke training device in an exploded state, showing the stand, first and second holder components;
FIG. 2 is a top rear left perspective view thereof;
FIG. 3 is a front elevation view thereof;
FIG. 4 is a rear elevation view thereof,
FIG. 5 is a right elevation view thereof;
FIG. 6 is a left elevation view thereof; and,
FIG. 7 is a top plan view thereof.
FIG. 8 is a bottom plan view thereof;
FIG. 9 is a top front right perspective view of the billiard stroke training devise with the base and the first holder component, shown separately for ease of illustration; and,
FIG. 10 is a top front right perspective view of the billiard stroke training devise with the base and the second holder component, shown separately for ease of illustration.