It was the 1940s, but you didn't offer that as a choice. At the start of the 1940s, each ball-in-play essentially took one run from the top of the playfield to the bottom (or a final resting place in a hole), and the player could only nudge. Skill pinball and gambling pinball had very similar play. Then we got flippers, and players could interact with the ball a lot.
.................David Marston