Baserunning is not a very big part of player value. In 2018, only one player gained more than a win thanks to his baserunning, and no player lost more than a win. A quick glance indicates that only around 20 percent of full time players even have their WAR impacted by more than half a win as a result of baserunning. So, it’s something that mostly helps (or hurts) at the margin. But that doesn’t mean we should ignore it.
So, what all goes into baserunning? Well, it’s three pretty simple things. The first should be obvious: stolen bases.