Doing everything possible to fail miserably at any task after success appeared inevitable. Snatching defeat from the
jaws of victory. Being
one's worst enemy. A reference to the tendency of the Michigan State Football team to dominate 3 1/2 quarters only to implode and give the
game away to their opponent, resulting in a frustrating defeat.
Example 1:
Bill overachieved all year to get that promotion, but got fired for sending that
joke about his boss to the whole company.
Bill really Pulled a Sparty.
Example 2: That girl has been into Jeff all night. I hope he doesn't Pull a Sparty and tell her about his Dungeons and Dragons collection.