The graphic is supposed to indicate the distance of a runner’s lead. In the majors, nine feet is considered a “standard” lead off first base. If a runner has more than a nine-foot lead, they enter the red area, which indicates that they are taking a bigger risk (more likely to get picked off, but also more likely to steal second base successfully). If the runner stays in the green area, closer to first base, it indicates that the runner is playing it safe and is less likely to attempt to steal second.