So if anyone in the infield fields a ground ball, and throws it to the first baseman to get the batter out, but they make a BAD THROW, which causes the first baseman to fall in front of the base runner’s path, which causes the base runner to run into the first baseman, the base runner is out. So they reward the defense for making a bad throw. Which is idiotic. Thats why they added the double base, so that the base runner can more easily avoid the first baseman, in the event of a bad throw. This was done in the effort to avoid injuries. That was super wordy and not sure if it made sense but it’s the best I could do.