MLB Stolen Base Predictions Tonight: Daily SB Probability Rankings (2026)
Every historical SB leaderboard shows you who stole bases last year. We answer a different question: which batters are most likely to steal a base tonight? Our model ranks tonight's lineup by P(SB ≥ 1). Top decile hits at 15.7% actual — 4x the 6.8% league baseline.
Published May 2026 · 13 min read · Fantasy MLB
1. Why Stolen Bases Matter in Fantasy Baseball
In standard 5x5 Rotisserie fantasy baseball — the format that most ESPN, Yahoo, CBS, and Fantrax leagues default to — stolen bases are one of five hitting categories that determine standings. The categories are batting average, home runs, runs scored, RBIs, and stolen bases. Each carries equal weight. A team that leads its league in stolen bases gains the same standings advantage as a team that leads in home runs.
That equal weighting is the key insight. Casual fantasy managers often draft heavily for power (home runs, RBIs) and treat stolen bases as a secondary concern. But in 5x5 Roto, neglecting the SB category means permanently conceding category points to managers who value speed — and recovering ground in SB is one of the hardest within-season adjustments because elite base stealers are scarce, get drafted early, and rarely appear on waivers.
The result is a structural market inefficiency: SB is systematically undervalued at drafts by casual managers and systematically overvalued by managers who obsessively target speed but ignore BA, HR, and RBI. The correct approach is to anchor the category with 1–2 elite stealers drafted at appropriate ADP, then use daily P(SB ≥ 1) projections to optimize your lineup on nights when steals are most likely to occur.
Stolen Bases in the Modern Game
The stolen base narrative has shifted dramatically since 2023. Larger bases (introduced under the new collective bargaining agreement) measurably improved success rates league-wide, and several teams began deploying aggressive base-running strategies that had been dormant since the stolen base peak of the 1980s. The result is more steals per game than any recent season — which increases the value of the SB category in fantasy formats that track it.
Even the most prolific base stealers steal in only 25-35% of their games at peak production. The league average batter steals in under 7% of games. This rarity is what makes per-game SB probability — not season totals — the correct metric for daily lineup optimization and waiver wire decisions.
2. The Math: League Baseline and Why Top Stealers Are 4x More Likely
Understanding the scale of the stolen base signal requires anchoring to the baseline. The league-wide P(SB ≥ 1) — the probability that any given batter in a given game will record at least one stolen base — is approximately 6.8%.
That 6.8% is the prior. A randomly selected starter on a randomly selected night steals a base in roughly 1 of every 15 batter-game appearances. The overwhelming base rate is zero: 93 in 100 batter-game appearances produce no stolen base. This is the statistical reality that most fantasy managers intuitively understand but rarely quantify.
What Elite Stealers Actually Look Like
An elite base stealer running at a 40-steal season pace over 150 games steals in approximately 27% of his games — roughly 4x the 6.8% baseline. A 60-steal pace player steals in approximately 40% of games.
These per-game rates are season averages. The per-night rate varies significantly based on the opposing pitcher's hold rate, the catching arm behind the plate, the score of the game, and whether the batter gets on base at all. Seasonal rates tell you the player's true SB talent. Per-game model predictions tell you which nights that talent is most likely to express.
Why P(SB ≥ 1) Is the Right Metric
Some fantasy resources express SB value as “expected SBs per 100 games” or “season projection at current pace.” These are useful for draft rankings. For daily start/sit and waiver wire decisions, the relevant metric is a binary per-game probability: will this batter steal a base tonight?
P(SB ≥ 1) answers that question directly. A probability of 28% means there is roughly a 1-in-3.5 chance of a steal tonight — not 1-in-15 like the baseline, and not a guarantee. The model surfaces the batters where tonight's specific conditions (opposing pitcher, catcher, recent form) point toward elevated steal probability — distinguishing which nights of a fast player's season are most likely to produce the stat.
3. How the Model Works: 20-Game Rolling Rate with Bayesian Shrinkage
Our stolen base model uses a last-20-game SB rate with Bayesian shrinkage toward the league baseline of 6.8%. The core logic mirrors what we use in the Quality Start model: recent performance weighted by sample size, pulled toward the prior to prevent over-reaction to hot streaks.
The Bayesian prior uses a sample of 30 games at the 6.8% baseline. This means a player who has stolen in 6 of his last 20 games (30% raw rate) is treated as approximately a 22-24% P(SB) player tonight — because part of that outperformance will regress, and the calibrated probability reflects what the model has validated against actual outcomes rather than naive recent-form extrapolation.
Backtest: 4.0x Lift at Top Decile
The model was backtested across multiple recent MLB seasons. Because SB is a low-frequency event, the relevant metric is not absolute accuracy but relative lift — how much more likely are top-ranked batters to steal versus a random pick?
The 8.9 percentage-point net signal — top decile vs. the shuffle test — confirms the model is capturing genuine information, not noise. A shuffle test takes the same batter-games, randomly assigns P(SB) rankings, and checks whether the “top decile” in a random ranking also hits at 15.7%. It does not — the shuffle test produces 6.8%, the base rate. The gap between 15.7% and 6.8% is the model's real contribution.
Key Additional Features
Beyond the 20-game rolling rate and Bayesian prior, the model encodes several matchup-level signals:
Opposing catcher CS rate: Catchers with above-average arms (30%+ caught-stealing rate) suppress SB probability. The model discounts per-game P(SB) when the opposing catcher is a known deterrent — one of the most underused factors in fantasy SB analysis.
Opposing pitcher hold rate: Pitchers with quick deliveries to the plate or strong slide-step mechanics suppress SB attempts. A base stealer facing a quick-delivery left-hander is in a materially different situation than the same runner facing a slow-tempo right-hander with a long wind-up.
On-base rate (recent): A player can only steal if he reaches base. A batter going through a low-OBP stretch has fewer opportunities per game to attempt a steal, which suppresses the per-game SB rate independent of his speed. Recent OBP is a soft constraint on the per-game probability.
Lineup position: Leadoff and #2 hitters generate the most steal opportunities because they bat in front of the lineup's best hitters and get the most PA per game. A speedy player dropped to the #7 spot faces fewer steal-opportunity environments — the model encodes this through plate-appearance rate.
Our model ranks tonight's full lineup by P(SB ≥ 1) — updated daily as lineups are confirmed. Top decile at 15.7% actual, 4x the league baseline. Built for 5x5 Roto, 6x6, and points leagues.
4. Top Base Stealers in MLB 2026 — Who to Target
Stolen base production in MLB concentrates at the top. The top 20 base stealers account for a disproportionate share of total league steals — a Pareto distribution that makes identifying the elite tier the most important draft decision for the SB category.
Tier 1 — SB Anchors (Draft Regardless of Other Considerations)
These players have sustained 30+ steal seasons and offer enough multi-category value that they are strong picks even in leagues where you do not desperately need SB:
Tier 2 — High-Volume Speedsters (Primary SB Contributor)
Players whose primary fantasy value is SB production, with secondary contributions in R and occasionally BA. Draft to anchor the SB category; accept lower production elsewhere.
José Siri — Elite raw speed, aggressive green light from managers, but thin batting average limits multi-category value. A pure SB specialist with 25-35+ steal pace when healthy.
Esteury Ruiz — A player whose entire value is speed. Low batting average and no HR power but one of the most aggressive base-running profiles in the league. In 5x5 Roto, he is a direct category-winner in SB and a liability in everything else.
Jorge Mateo — Consistent 20-25 SB pace when he has a full-time role. Below-average bat but usable speed profile for managers targeting SB specifically.
How Per-Night Rankings Differ from Season Rankings
A player ranked #1 in season SB is not necessarily the best P(SB) pick on any given night. The per-game model adjusts for several factors that season rankings cannot capture:
Recent form vs. injury caution: An elite stealer returning from a hamstring issue is less likely to run aggressively in his first few games back. The 20-game rolling window captures reduced steal attempts automatically.
Opposing catcher: Even Acuña is less likely to steal against Adley Rutschman than against a below-average CS catcher. The model adjusts for this nightly — the season ranking does not.
Opposing pitcher tempo: A left-handed pitcher with a quick slide-step creates materially different conditions than a slow-tempo right-hander. The per-game model encodes pitcher-specific hold tendencies when available.
5. Format-Specific Value — How SB Scores Across Platforms
Stolen bases score differently across the major fantasy platforms and format types. Understanding your specific format is essential for correctly weighting SB in your strategy.
5x5 Rotisserie — SB as a Direct Counting Category
In standard 5x5 Roto, stolen bases are one of five equally weighted hitting categories. Every steal adds one to your SB total, and the standings are determined by your cumulative SB rank across the league. Finishing last in SB costs the same standings points as finishing last in home runs. Finishing first in SB is as valuable as finishing first in any other category.
The practical implication: in a 12-team league, the difference between first and last in SB can represent 11 standings points — a large enough gap to swing the title. Drafting 1-2 elite stealers at appropriate ADP and using per-game P(SB) to optimize lineup decisions daily is the correct approach. Do not treat SB as a secondary category in 5x5.
6x6 Rotisserie — SB Still a Category
In 6x6 formats (which typically add OBP or SLG as the sixth hitting category and QS or K/9 as the sixth pitching category), SB remains a direct scoring category with identical weight. The addition of a sixth hitting category does not dilute SB — it adds a sixth independent dimension. In fact, players who contribute to SB, OBP, and HR simultaneously (Acuña, Witt Jr., Carroll) become even more valuable in 6x6 because they help in more categories per draft slot.
Points Leagues — SB as a Per-Event Bonus
In points leagues, stolen bases convert to a fixed point value per event rather than a category rank. The value varies significantly across platforms:
| Platform | SB Points | CS Penalty | Expected SB pts / game (elite stealer) |
|---|---|---|---|
| ESPN | +4 | -1 | ~1.0–1.3 pts/game (40 SB pace) |
| Yahoo | +5 | -2 | ~1.2–1.5 pts/game (40 SB pace) |
| CBS | +3 | -1 | ~0.7–1.0 pts/game (40 SB pace) |
| Fantrax | +3 to +5 | varies | ~0.8–1.2 pts/game (40 SB pace) |
In points leagues, the primary driver of a speed player's value is batting average and run production — the counting stats that accumulate across every plate appearance. SB adds meaningful bonus points but is not the defining valuation lever unless your specific league's SB weighting is unusually high. Use P(SB ≥ 1) to identify the nights a speedster is most likely to contribute the SB bonus on top of his normal line.
6. Common SB Analytical Pitfalls
Three systematic mistakes explain why many fantasy managers either over-invest or under-invest in stolen bases relative to their optimal strategy.
Pitfall 1: Overweighting Season SB Totals vs. Recent Form
A player who stole 45 bases last season but is on pace for only 15 through the first six weeks is not the same SB asset as he was at draft time. Season totals anchor perception in ways that resist updating — the “46-SB last year” number stays in the fantasy manager's head long after the player has changed his role, lost a step to injury, or been dropped in the batting order where steal opportunities are fewer.
Our model corrects for this explicitly. The 20-game rolling rate with Bayesian shrinkage updates nightly. A player who has not stolen a base in his last 18 games will show a materially lower P(SB) in the model output than his season total or draft ranking would suggest — giving you an early signal to consider alternatives before the season narrative catches up to the data.
Pitfall 2: Ignoring Catcher Arm Quality
This is the most significant matchup factor in stolen base prediction that fantasy managers routinely ignore. Elite defensive catchers — Adley Rutschman (BAL), William Contreras (MIL) — throw out runners at 30-35%, well above the 25% league average. Running against an elite arm reduces expected steal probability by roughly 20-25%.
Conversely, catchers with below-average arms (caught-stealing rate below 20%) are exploitable by even moderate-speed runners. A catcher throwing out only 15% of steal attempts is such a soft target that managers green-light runners who would normally not be running. The per-night catcher matchup often matters as much as the base stealer's own speed.
Our model encodes opposing catcher CS rate as an explicit feature — one of the most defensible differentiators versus generic SB projection tools that rank players only by season rate.
Pitfall 3: Ignoring Pitcher Hold Rate
Pitcher tempo to the plate is the other half of the steal equation that season totals cannot capture. Left-handed pitchers have a structural advantage over base stealers because they naturally face first base during their delivery — but more importantly, pitchers with quick step deliveries, slide-steps, or exceptionally fast times to the plate suppress steal attempts regardless of handedness.
A manager who green-lights a base stealer every night without checking the opposing pitcher's hold tendencies is leaving information on the table. The per-game model incorporates pitcher-level hold tendencies, which means nights where a known hold-specialist is starting will show depressed P(SB) even for elite speedsters — a signal that season totals and generic projections cannot provide.
7. How to Use the Stolen Base Projections Page
The /stolen-base-projections page publishes P(SB ≥ 1) rankings for every confirmed lineup starter for tonight's MLB slate. Here is the recommended workflow for using it in your fantasy decisions.
Daily Start/Sit Decisions
For 5x5 Roto managers who flex players across positions, the per-night P(SB) ranking helps identify the maximum-value lineup configuration. A speedster with a 25% P(SB) on a night where his catcher matchup is favorable and the opposing pitcher is slow to the plate is a must-start. The same player at 12% against an elite catcher and quick-release lefty is a lower-priority start in a tight race for the SB category.
Waiver Wire Pickups
Speed is consistently undervalued on the waiver wire because casual managers check season SB totals and see a player's hot steal streak as “used up” after the fact rather than as a signal. The P(SB) model helps identify:
Rising stealers: A player whose 20-game SB rate is increasing relative to his season pace is gaining momentum that the season total has not reflected yet. The model will show a higher P(SB) than his owned percentage might suggest — a waiver opportunity before the community catches up.
Favorable matchup streamers: Some players with modest speed get elevated P(SB) rankings when the opposing pitcher is exceptionally slow to the plate or the opposing catcher has a poor CS rate. These are one-game streamers for SB category pushes in H2H weeks.
Cross-Reference with Home Run Rankings
For multi-category fantasy managers, the /home-runs page and the SB projections page together identify the rare nights where a multi-tool player (Witt Jr., Carroll, De La Cruz) is highly ranked in both categories simultaneously. These “confluence nights” are the most valuable single-player lineup slots for managers contending in both SB and HR categories. Also check /pitcher-quality-starts to see if tonight's opposing pitcher is a high-K arm — high-K pitchers tend to post faster paces and may suppress steal opportunities on the same night.
Use SB rankings alongside HR and QS projections to identify multi-category nights for your speed-power hitters — Witt Jr., Carroll, De La Cruz often rank high in more than one tool simultaneously.
8. Frequently Asked Questions
What is a stolen base in fantasy baseball?
In fantasy baseball, a stolen base (SB) is one of the five standard counting categories in 5x5 Rotisserie leagues — alongside HR, R, RBI, and batting average. Every time a player successfully steals a base in a real game, it counts toward your fantasy SB total. SB carries equal weight to home runs in 5x5 Roto; finishing first in SB earns the same standings points as finishing first in HR. In points leagues, a stolen base typically adds +2 to +5 points depending on platform.
Who are the best base stealers in MLB 2026?
The top recurring base stealers include Ronald Acuña Jr. (ATL), Bobby Witt Jr. (KC), Corbin Carroll (ARI), Elly De La Cruz (CIN), José Siri, Esteury Ruiz, and Jorge Mateo. Elite speedsters steal in 25-35% of their games — roughly 4-5x the league baseline of 6.8% per game. In fantasy, these players anchor the SB category for an entire roster. Our per-game model identifies which specific nights each player's steal probability is elevated or suppressed by matchup context.
How accurate are stolen base predictions?
Our model shows the top decile of P(SB ≥ 1) rankings produces an actual SB rate of 15.7% — 4.0x the 6.8% league baseline, representing an 8.9 percentage-point net signal above a random shuffle. SB is a low-frequency event (under 7% of batter-games), so the relative lift — not the absolute rate — is the meaningful accuracy metric. A top-decile player is four times more likely to steal tonight than a randomly selected starter.
Should I draft for stolen bases in fantasy?
In 5x5 Roto leagues, SB is a direct counting category equal in weight to HR — so yes, dedicating draft capital to elite base stealers is standard strategy. A single top-10 SB player (40+ SB season pace) can anchor your SB category while you fill HR from power hitters elsewhere. In points leagues, SB adds +2-5 points per steal — real value, but not category-defining unless your league weights it heavily. Draft 1-2 elite SB contributors regardless of strategy in any 5x5 Roto league.
What is P(SB ≥ 1)?
P(SB ≥ 1) is the model's estimated probability that a specific batter will record at least one stolen base in tonight's game. The league baseline is approximately 6.8% per game for all starters — meaning roughly 93 in 100 batter-game appearances produce no stolen base. Elite speedsters have a P(SB) of 25-35% on a favorable night. The model uses last-20-game SB rate with Bayesian shrinkage toward the 6.8% baseline to produce calibrated per-game probabilities.
Do stolen bases matter in points leagues?
In ESPN default points leagues, a stolen base adds +4 points and a caught stealing subtracts -1. In Yahoo, SB is typically +5 with -2 CS. In CBS points, SB adds +3. For elite stealers (Acuña, Witt Jr.), the expected SB points per game can reach 1.0-1.5, a meaningful daily contribution. Use P(SB ≥ 1) to identify which nights a speedster is most likely to attempt and succeed — and which nights a tough catcher matchup makes the steal bonus unlikely.
How do catcher arms affect stolen base predictions?
Catcher caught-stealing rate is one of the most significant SB context factors that most tools ignore. Elite catchers (Adley Rutschman, William Contreras) throw out runners at 30-35%, well above the 25% league average. Running against an elite arm reduces expected SB probability by roughly 20-25% relative to a baseline matchup. Our model encodes opposing catcher CS rate as an explicit feature, which explains part of the 4x lift at top decile — nights ranked highest are nights where the catcher matchup favors the runner, not just nights where a fast player is in the lineup.
Can speedy hitters steal every game?
Even elite base stealers steal in only 25-35% of games at peak production — they fail to steal in 65-75% of their games. The league baseline is 6.8% per game. Stolen bases require specific conditions: the player must reach base, first base must be open, the pitcher must not be holding the runner tightly, and the batter must get a good jump. No player steals every game — per-game SB probability, not season total, is the correct metric for daily fantasy decisions.
View tonight's SB rankings →
Per-game stolen base probability for every confirmed lineup starter. Top decile at 15.7% actual — 4x the league baseline. Built for 5x5 Roto SB category decisions and daily fantasy lineup optimization. Updated daily.
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