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.
by htos_drol November 13, 2011
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