It’s no surprise: players are stealing more bases in 2023. With the new rule changes coming into play at the MLB level this year, the stolen base is back in business. All three of these rule changes directly contribute to the stolen base revival: Bases are now three inches bigger, pitchers are limited in their pickoff attempts, and the pitch clock is in effect. Stolen bases have declined by 24% in the last ten years, but the rule changes have bucked the trend. As of June 26, stolen bases have increased 44% from last season.
Not only have stolen bases improved from an overall total perspective, but players are stealing bases more effectively than ever. The league-wide stolen base success rate is now at 80%, which is 5% higher than in 2022. This is continuing a trend over previous years: teams are smarter about when to steal bases. It aligns with the increased importance of on-base percentage, as teams want to reduce outs both at the plate and on the base paths. The current 80% success rate is on pace to be the highest in MLB history.
Jack Conner’s piece here last month assigned value to stolen bases in the current environment, but we can also identify who is using these new rules to steal bases. Are the elite speedsters separating themselves from the pack? Or are the 10-15 SB players nabbing an extra base or two?
Dividing the Player Pool
There’s no perfect way to divvy up the player pool, but I decided to use Baseball Savant’s sprint speed. I chose this over stolen bases themselves because sprint speed can also indicate stolen base totals across seasons and can be compared in-season. There is a positive correlation between sprint speed and stolen bases, but it is not perfect. An obvious example is a guy like Mike Trout, who ranks 17th in sprint speed but only has one stolen base.
I split the player pool into their respective percentiles to create five groups. The highest categorization is “elite,” which consists of those with a sprint speed above 30 ft./sec. These players are all in the 99th percentile for sprint speed and are considered top-end speedsters. From there, the rest of the percentiles go from the upper quartile (75th percentile to 99th percentile) to the lower quartile (0th percentile to 25th percentile). The actual sprint speed ranges and examples (to bring some semblance of context to running speeds) are as follows:
These buckets of players were used to calculate averages in stolen base statistics in both 2022 and 2023, as well as changes year over year.
2022 & 2023 Stolen Base Landscape
These numbers were taken thru 79 games of the 2022 MLB season, which is an equal part to where we are in 2023. These stats show very clearly that the faster a player is, the better they were at stealing bases. Not only were faster players stealing more, but they were more successful as well. Part of this is that there is only a handful of players at that elite tier, but those players are by far and away the most elite base stealers in the game. Furthermore, the elite tier of base stealers was over one-and-a-half standard deviations above the next tier. This emphasizes how useful the top speedsters are, as the middle three tiers are all within a standard deviation of each other.
The success rate also was consistent with the elite group having the biggest gap from the next tier out of any other tier. Interestingly, the 50th percentile and above are all above a 50% success rate, while below-average runners have a poor success rate.
In 2023, stolen bases (not surprisingly!) are up in every category except the slowest tier. The elite tier has separated itself further in 2023 than in 2022. Even though the standard deviation has increased, meaning that the stolen bases are more widely dispersed, the elite tier is two standard deviations above the 75+ percentile. Even with the dominant Ronald Acuña Jr. and Esteury Ruiz on the base paths, the 75+ tier still fell behind the top group.
Comparing 2022 and 2023 creates a few key storylines around stolen bases looking forward:
On average, the top group has added about 6 stolen bases, while each of the two above-average tiers has added at least an extra stolen base. The elite tier is now finding itself in situations where they can run wild. Elly de la Cruz has exemplified this, as his 30.8 ft/sec speed (fastest in 2023) has set him off to the races. He has 8 stolen bases in 16 games, which would put him second in baseball (only trailing Ruiz) if he was at this pace all season.
Those who have the capability to run are taking that opportunity to run more often. The 7% increase in success rate for the 50-75 percentile pairs with a slight decrease in caught stealing, suggesting that above-average runners are being smarter on the base paths. They have also swiped almost as many bags as the group above, despite having less growth from 2022.
Going forward, the fastest guys in baseball are furthering the gap between them and anyone else. However, that doesn’t mean that stolen bases are following the trends of the last few years. The limited number of elite players has only resulted in a 30 stolen base gain, whereas the bigger groupings of players show that there are more stolen bases available to everyone.
Great snapshot. Interesting to see how the rule changes have affected different groups differently.
would be interested to see if teams are taking advantage of good matchups more than last year. like teams playing dodgers or white sox are running at will