You’ll have to click through the article to see who topped his chart. FYI, it wasn’t Speedy Gonzales. Although he certainly had the speed and the strike zone to be an effective leadoff hitter. I have not been able to find any video that suggests he ever took up the sport.
I’m mostly certain when I suggest that speed produces runs in three main ways: by means of defensive range, baserunning (both via the stolen base and other manner of advancement), and infield hits/drag bunts. In the case of the first two elements (range and baserunning), speed alone isn’t even responsible for the entirety of the skill. There are excellent defenders, for example, whose range is due not only to footspeed but also to making good reads on, and taking straight paths to, batted balls. Likewise, there are players with merely average speed who, nevertheless, are above-average baserunners due to excellent decision-making. For the sake of this post, however, both elements will be considered purely as expressions of footspeed.
Here’s what I found:
For defense, the average top-10 leader has saved 15 runs, or 1.5 wins, relative to league average over the last five seasons. For baserunning, a top-10 leader has been worth ca. 8.0 runs per season over the last five years.
So, broadly speaking, we can say that the upside for a player with elite speed — in terms of defense and baserunning — is something like 20-25 runs, or 2.0-2.5 wins.