Grand Slam

The Grand Slam, manufactured by the National Automatic Machine Company of St. Paul, Minnesota, in 1933, is a rare and enigmatic example of pinball's mechanical roots. It is a pure mechanical (PM) payout machine — a coin-operated game with no electrical components that could reward winning play automatically, placing it in the gambling-adjacent branch of the early pin game industry.

Beyond its type and its September 1933 production date, the Grand Slam's specific gameplay features are largely shrouded in mystery due to the scarcity of surviving information. Like other purely mechanical games of the era, play would have centered on launching balls with a plunger and hoping they settled in scoring positions — flippers and powered bumpers were still years in the future.

The Grand Slam's significance lies not only in its age but also in its obscurity: it is a little-documented artifact from a short-lived Minnesota manufacturer, which makes it all the more intriguing to those seeking to uncover the secrets of early pinball history.