According to an analysis by University of Minnesota professor Eric J. Ostermeier, who writes the Smart Politics blog, a National League victory in the Mid-Season Classic has preceded every election with double-digit GOP House gains since 1950.

The pattern is similar in the Senate. Since 1948, every time the National League has won Republicans have gained at least five Senate seats. The flipside, however, is also true in the upper chamber: American League victories have preceded Democratic gains of five or more Senate seats since 1948.

The type of victory, it seems, is also revealing. Ostermeier’s study found that when the National League rallied late in the game to win, Republicans made landslide House gains, ranging from 34 seats to 54 seats.