When it comes to stealing bases, obviously, speed kills. The players who have the fastest average stolen base attempt times usually have the greatest amount of stolen bases. As you can see in the chart below, there is a negative relationship between average speed and total bases stolen. That means that as speed increases, or the slower the runner, the amount of stolen bases decreases. However, how does pure attempt speed impact the success of the base stealer? Clearly, faster players are going to attempt to steal more bases. However, if they are more frequently thrown out than slower, more strategic base stealers, then the value of their speed is much less. The mission here is to determine the value a player or prospect could find by increasing his stolen base attempt speed.
In order to further examine this, let’s compile data to compare average stolen base attempt time with stolen base success rates. The data collected is from the total 2014 season until July 9 – theoretically half of a season. We took all of the players who had greater than 5 stolen base attempts and found the average speed per attempt. Then, we charted this comparison to produce the graph below.
This graph clearly shows once again a negative relationship between average attempt time and percentage success. However, the relationship between the decrease in stolen base percentage (thrown out more frequently) and the increase in attempt time (slower) is much stronger. Although it may seem obvious that faster players are better base stealers, it does show that increasing one’s attempt speed could provide a great return in terms of greater stolen base success. Let’s take a look at a few players to get a better grasp of this.
|Runner||average sb time||Stolen Base Percentage||Total SB attempts|
If you take a lake at this table, that encompasses top, middle, and low tiers of the 90 players in the study, you will see that there is some variation amongst speed and success. However generally, you can see that the slower players have the lowest success times. Pedroia, Kemp, and Wright are all sluggish on their attempts and have low success rates yet they still attempt to steal regularly. On the other hand, Crisp, Gomez, Pollack, and Gordon are among the swiftest thieves and also sport high success rates. An interesting note is that Jarrod Dyson is a half second faster then the anointed King of Speed Billy Hamilton. Hamilton may have him from home to first, but Dyson is the fastest when attempting to steal a base. Additionally, Dyson’s success rate, with several fewer attempts, is slightly better than Hammilton’s. This suggests that Dyson could be the best base stealer in baseball if he went more.
In conclusion, the relationship between stolen base attempt time and percentage is a negative one which posits that a large amount of the variation on the stolen base success percentage is based in the time. Although we can never deem causation from improving speed, it is reasonable to assume that if a prospect were to decrease his stolen his speed by just more than a tenth of a second then he could greatly improve his stolen base success and therefore become a more valuable player.