There is more to baserunning than the stolen base. In fact, that is only one method for which a baserunner can advance on the basepaths. He can advance on a deep fly ball or a ground ball to the opposite side of the infield. Then there is the simple savvy of not getting thrown out due to poor judgement.
Baseball Prospectus uses a stat called base running runs (BRR) to measure the overall effectiveness of a base runner.
It measures the number of runs contributed by a player's advancement on the bases, above what would be expected based on the number and quality of the baserunning opportunities with which the player is presented, park-adjusted and based on a multi-year run expectancy table. BRR is calculated as the sum of various baserunning components: Ground Advancement Runs (GAR), Stolen Base Runs (SBR), Air Advancement Runs (AAR), Hit Advancement Runs (HAR) and Other Advancement Runs (OAR).
It may surprise some to see the top five baserunners of 2013 according to Baseball Prospectus.