The ball was also hard to hit because pitchers could manipulate it before a pitch. For example, the spitball pitch was permitted in baseball until 1921. Pitchers often marked the ball, scuffed it, spat on it—anything they could to influence the ball's motion. This made the ball "dance" and curve much more than it does now, making it more difficult to hit. Tobacco juice was often added to the ball as well, which discolored it. This made the ball difficult to see, especially since baseball parks did not have lights until the late 1930s. This made both hitting and fielding more difficult.