As a Cardinal fan growing up in the mid-80's I can certainly say that I've seen some great baserunning over the last 30 years or so. From the Runnin' Redbird heyday with Vince, Willie and the rest of the gang all the way through the steamroller that was Albert Pujols, Cardinal fans know what great baserunning looks like -- taking the extra base on a soft single, stealing third when the pitcher gets in a rhythm and isn't paying you any mind, knowing the arms and range of the outfielders to get a good jump from second on a single and beating a weak throw home.
The casual fan associates great baserunning with great speed and quickness, but the experienced fan knows there's more to it than that. While it certainly helps to be fast, there's also an innate ability to read any situation based on a combination of experience and instinct, much like a salty old poker player getting a read on the new fish at the table having just met him not ten minutes before. The great baserunners seem to know what's going to happen on a particular ball in play or when a pitcher is going home almost before it happens, as if they can glimpse the future just a few seconds ahead of the rest of us. Base coaches are a mere obstacle rather than a guide.
Kolten Wong might just be one of those guys.
I know, I know -- getting picked off in the World Series is hardly the type of thing that would happen to a great baserunner. But the fastest man in the game once lost a race to an automatic tarp roller. Baseball is weird like that sometimes.
Watching Wong run the bases reminds me quite a bit of Albert Pujols actually: Aggressive, intuitive, occasionally makes an out when he probably shouldn't but always by putting pressure on the defense and forcing them to make a perfect throw, relay, or tag to put them out.
The numbers back this up, at least with respect to former Cardinals. Wong's 5.4 baserunning runs ranks 14th among Cardinal players since 1984. That's some pretty good company even before you consider that Wong has the fewest plate appearances and fewest games played of anyone in the top fifty Cardinal baserunning seasons in that span.
If we extrapolate Wong's baserunning runs over 600 PA's (5.4 / 415 * 600) he would be worth 7.8 runs on the basepaths,* which would be good for third in the National League in 2014, behind one dimensional speedsters Dee Gordon and Ben Revere and putting him behind only Vince Coleman, Tony Womack, and Lou Brock among Cardinal players since 1964.
That's really good company. If you combine this elite baserunning with Wong's above average defense at second base and you have a 1.0-1.5 fWAR player before batting runs are brought into the equation. That's a solid baseline for a middle infielder, and especially a left handed one who can hit for power and has elite contact skills.
BsR isn't necessarily predictive until it has more than one season of data to measure while being fairly precise in measuring past performance. This makes it similar to a defensive metric like UZR: While we can't necessarily determine true talent level based on a one season sample, we can infer how a player performed over that season in terms of runs.
Given that good baserunning is even more important with runs are scarce, and given the current trend towards a lower run scoring environment, it's a good time for the Cardinals to have their best baserunner in a decade or more.
*Yes, I'm aware that this is a bit of a quick and dirty calculation, but since BsR is calculated by compiling baserunning performance it's reasonable to think that a linear extrapolation is useful for comparing players to each other by normalizing plate appearances as a reference for playing time.