Sprint Speed and Baserunning Metrics
What Statcast sprint speed measures in feet per second, what a bolt is, how stolen-base value and baserunning runs are calculated, and why a fast player is not always a good baserunner.
Speed is the easiest tool in baseball to see and one of the hardest to measure well. Everyone in the park can tell when a runner is fast. What they cannot tell is how much the speed is worth: whether a player who steals thirty bases is helping his team or hurting it, whether the man who scores from first on a double is faster than the man who stops at third, or whether a quick runner who reads pitchers poorly is a net plus. The tools for answering those questions have changed a great deal in the last decade.
The most visible new tool is sprint speed, a Statcast measurement in feet per second. The older tools are the stolen-base columns of the box score and the run-value systems that convert baserunning events into runs. This article explains each of them, shows how the arithmetic works, and uses the historical record to show how much the stolen-base game has changed since the 1980s. The central point is simple: speed is an input, baserunning is a skill, and the two are measured separately.
What sprint speed measures
Sprint speed is Statcast's measure of how fast a player runs, reported in feet per second. It is defined as the player's average speed in his fastest one-second window during a competitive run. That definition is deliberate. A runner takes some time to accelerate, so the speed at any moment depends on how far into the run he is. The one-second window picks the point where he is moving fastest and ignores the first few steps, which makes the number comparable between a runner going from first to third and a batter beating out a grounder.
The word "competitive" matters too. Statcast counts the runs in which the player was trying to get somewhere as quickly as possible: a ground ball he is trying to beat out, a hit on which he advances from first to third, a scoring attempt. It does not count a trot after a home run or an easy jog on a routine fly ball. A player must have a minimum number of qualifying runs in a season to appear on the leaderboard, so a regular who rarely has a reason to run hard may appear based on fewer attempts than a leadoff hitter.
The scale is easy to read. A typical major leaguer runs about 27 feet per second. A figure of 30 feet per second or higher is elite, and Statcast calls any single run at that speed or faster a bolt. Players are often described by how many bolts they have in a season, which is a way of showing how often a runner reached top speed rather than only what his single best run looked like.
What the feet-per-second number means in practice
The distance between bases is 90 feet. At a constant 27 feet per second, a runner would cover it in about 3.3 seconds, and at 30 feet per second in 3.0 seconds. Real times are longer than those figures because nobody starts a run at top speed. A runner who is stationary at the plate or standing a few steps off first base takes time to get to full speed, which is why an elite sprinter and an average one are closer over 90 feet than the speed figures suggest.
That arithmetic explains two features of the statistic. First, a difference of one foot per second looks small but compounds: over a 90-foot run, it is roughly a tenth of a second at top speed, and a tenth of a second is the difference between safe and out on a close play. Second, sprint speed relates to some outcomes more than others. It tends to matter for infield hits and of taking extra bases, where the run is long and the ball is in play, and less for stolen bases, where the first step, the timing of the pitch and the catcher's arm all matter at least as much as top speed.
Speed also changes with age. Players generally lose some of it as they get older, which is why a stolen-base total built early in a career can decline without any change in effort. This is a general feature of athletic performance, and readers who want the specific rate of decline should look at the leaderboard by age rather than rely on a rule of thumb.
Why speed alone does not make a good baserunner
Sprint speed measures the engine. Baserunning is the whole vehicle. A runner needs several other abilities that the speed number does not capture:
- The jump. How quickly a runner reacts to a pitcher's first move or the sound of the bat. Two runners with identical top speeds can differ by several steps on a steal attempt because one reads the pitcher better.
- The lead. How far off the base the runner stands. A bigger lead shortens the distance to the next base but gives the pitcher a better chance of picking him off.
- The read. Whether to go on a ball in the dirt, whether to tag on a fly ball, whether to try for third on a single to right. These decisions depend on the arm of the fielder, the number of outs and the score.
- Slides and turns. Rounding a base cleanly and taking a good angle saves fractions of a second that never show up in a sprint-speed number.
Statcast now publishes information about several of these elements, including how far a runner is from the base at the pitch and how he gets off the mark. Those figures are tools, but the central fact is the same: a fast player who cannot read pitchers will cost his team outs, and a slower player with excellent instincts can add value. The best baserunners combine both.
The oldest metric: stolen bases and caught stealing
For more than a century, the box score has recorded stolen bases (SB) and caught stealing (CS). The most obvious way to evaluate a base stealer is his success rate: stolen bases divided by attempts, which is SB divided by the sum of SB and CS. The historical career leaders show the top of the list.
| Player | Stolen bases | Caught stealing | Success rate |
|---|---|---|---|
| Rickey Henderson | 1,406 | 335 | 80.8% |
| Lou Brock | 938 | 307 | 75.3% |
Henderson also holds the modern single-season record with 130 steals in 1982, and Maury Wills's 104 for the National League in 1962 is the other number every fan knows. The two columns above point at the same thing: Henderson stole far more bases than anyone, and he was also more efficient than Brock. For a profile of the other great base stealer, see Lou Brock: The Stolen-Base King of His Time.
The historical caught-stealing counts are complete for the modern era, though some early seasons lack the column, so success rates for nineteenth-century players or those from the early decades should be treated with care.
When a stolen base helps and when it hurts
A stolen base is worth something, but not as much as a caught stealing costs. That asymmetry is the core of the analysis, and it comes from run expectancy, the average number of runs a team scores from a given situation to the end of the inning.
Moving a runner from first to second raises the expected runs a little. Losing him to a caught stealing removes a baserunner and adds an out, and both of those are expensive. In a typical modern run environment, the standard approximation is that a steal is worth about two-tenths of a run and a caught stealing costs about four-tenths. These numbers vary a little by season and by the number of outs and the score, so treat them as round figures.
With those values, the break-even success rate is a simple calculation. If a steal gains 0.2 runs and a caught stealing loses 0.4, a runner needs to succeed twice as often as he fails to come out even, which is two out of three, or about 67 percent. If the cost of a caught stealing is a little higher, the break-even point moves toward 70 percent or higher. That is why analysts often say that a runner needs to be successful roughly 70 to 75 percent of the time before attempting a steal makes sense, depending on the situation.
A worked example shows how this plays out. A player who steals 30 bases and is caught 15 times has a success rate of 67 percent. Using the round values above, he gained 30 times 0.2, or 6 runs, and lost 15 times 0.4, or 6 runs. His net contribution from stealing is zero, despite the 30 steals that appear on the back of his baseball card. A player who steals 20 and is caught 5 times gains 4 runs and loses 2, a net of 2 runs, which is better than the first player's total with 10 fewer steals.
How the stolen-base game has changed
The league success rate has risen over time, and the 2023 season was a notable break. The table below is computed from the historical Batting table, adding up both leagues.
| Season | Stolen bases | Caught stealing | League success rate |
|---|---|---|---|
| 1982 | 3,176 | 1,617 | 66.3% |
| 2000 | 2,924 | 1,323 | 68.8% |
| 2012 | 3,229 | 1,136 | 74.0% |
| 2022 | 2,486 | 811 | 75.4% |
| 2023 | 3,503 | 866 | 80.2% |
| 2024 | 3,617 | 961 | 79.0% |
Two things stand out. The rate climbed from about two-thirds in the early 1980s to about three-quarters in the 2010s, which is consistent with teams running mainly in the best situations. Then in 2023 the number of steals jumped by more than 1,000 in a single year, with the success rate passing 80 percent. The 2023 league leader was Ronald Acuña Jr. with 73 steals, ahead of Esteury Ruiz with 67 and Corbin Carroll with 54. In 2022 the league leader had 41.
The 2023 rule changes explain the break. MLB introduced the pitch clock, limited pitchers to two disengagements per plate appearance, and made the bases larger, which shortened the distance between them slightly. Each one helped the runner. The clock reduced the time a pitcher could take to hold a runner, the disengagement limit restricted pickoff throws, and the bigger bases meant a few inches less to cover. The mechanics of the clock are in the pitch clock in detail.
Baserunning runs: the full picture
Stolen bases are only a fraction of what a runner does. A complete baserunning metric tries to count everything: steals, caught stealing, taking extra bases on hits, advancing on fly balls and wild pitches, getting thrown out on the bases and grounding into double plays. Several public systems do this with slightly different methods.
- wSB (weighted stolen base runs) converts steals and caught stealing into runs, using the values above and comparing the result to what an average player would have produced given the same number of opportunities.
- UBR (ultimate base running), developed by Mitchel Lichtman, assigns run values to every other baserunning event, such as going from first to third on a single or being thrown out trying to stretch a hit.
- wGDP counts the double plays a hitter grounds into against the league average, because avoiding them is partly a function of speed.
- BsR, the version used by FanGraphs, combines wSB, UBR and wGDP into one figure in runs.
- Baseball-Reference and Baseball Prospectus publish their own versions with their own names and details, and Statcast publishes a baserunning run value built from its tracking data.
The systems agree on the broad outline and differ in the details, so it is more reliable to compare players within a single system than between them. A good baserunner is usually worth a few runs per season above average and an excellent one perhaps more, which makes baserunning a smaller piece of a player's value than hitting but a real one.
Extra bases taken: the skill speed can't buy
One of the most revealing figures is the percentage of extra bases taken, which counts how often a runner advances more than one base on a single or more than two on a double when the opportunity exists. It is a measure of decisions, not just speed. A very fast runner who is held at third by an aggressive coach does not get credit, and a slower player who takes the extra base against a weak arm does.
This is also where the relationship between speed and value is clearest. A runner at 27 feet per second who knows that the left fielder has a weak arm and that the shortstop is cutting off the throw can take extra bases that a 30-foot-per-second runner would not attempt. Sprint speed gives a runner the option, and baserunning intelligence decides whether to use it. The same distinction applies in the field, where speed is an input and range is a result, as explained in defensive metrics and in fielding percentage and range factor.
Using these numbers in fantasy and analysis
For fantasy players, stolen bases are a scarce category, and the changes of 2023 made them less scarce, which raised the supply and changed how rankings value them. How fantasy rankings are built explains why a category's scarcity decides how much a player in it is worth.
For analysis, the practical advice is short. Use sprint speed to see who can run, success rate and baserunning runs to see who does it well, and extra-bases-taken to see who makes good decisions. Do not use stolen-base totals alone. A figure of 30 steals tells you nothing about the cost of the times the runner was out. Pair it with the sprint-speed leaderboard and the baserunning runs for a player to see the full picture, and use expected statistics for the other side of a player's profile, since a fast player will often beat out ground balls that look like outs on paper.
Common questions
How fast is fast in feet per second? About 27 feet per second is typical for a major leaguer. Thirty or higher is elite, and a run at that speed counts as a bolt.
Is sprint speed the same as home-to-first time? No. Home-to-first time measures a whole run, including the start and the swing. Sprint speed measures the fastest one-second stretch of the run.
What success rate do you need to make stealing worthwhile? Roughly two-thirds to three-quarters, depending on the situation and the run environment, using the round run values in this article. Check the current figures for your season if precision matters.
Why did stolen bases jump in 2023? The historical data show 3,503 steals in 2023 against 2,486 in 2022. The pitch clock, the limit on pickoff attempts and larger bases were all introduced that year, and each helped runners.
Does a fast player always steal a lot of bases? No. Stealing depends on reading the pitcher, the jump, the manager's approach and the catcher. Some of the fastest players run rarely, and some modest runners steal efficiently.
Where to go next
For the catcher's side of the stolen base, read catcher framing explained, and for another measurement system that turned a skill into numbers, see exit velocity, launch angle and barrels. Career and season stolen-base leaders are on the leaders page, and you can work out a runner's success rate yourself with the stat calculator.