Padres Series Win Prob
74.2%
Needs 1 more win in 2 games
SD
San Diego Padres
NLDS Game 3 Winner
2
VS
1
MIL
Milwaukee Brewers
Trailing 1-2
Padres lead 2-1 (NLDS Best-of-5)
Brewers Series Win Prob
25.8%
Must sweep G4 & G5
Upcoming Game Leverage (SLI)
2.14
Swing on Game 4: +25.8% / -48.4%
Expected Total Games
4.48
51.6% chance series ends in G4
Gold = Padres Win State | Blue = Brewers Win State | Glowing Node = Active State
Click any circle to jump directly to that series score
| Outcome Path | Final Score | Series Champion | Exact Probability | Games Played |
|---|
Series Leverage Index (SLI) by Game: Quantifies how much each individual contest swings the overall series win expectation compared to an average playoff game.
Series Outcome Distribution & Length Probability
Best-of-5 Division SeriesWhy Taking Game 3 in a 1-1 Best-of-5 is the Ultimate Series Pivot
In baseball postseason lore, a 1-1 tie heading into Game 3 represents maximum volatility. When the San Diego Padres took Game 3 vs. the Milwaukee Brewers to capture a 2-1 series lead, their probability of advancing surged from a coin-flip 50% territory up to roughly 74% to 78% depending on home-field advantage and starting pitching rotations.
Historical MLB Best-of-5 Precedent:
Teams taking a 2-1 lead in any best-of-5 MLB postseason series (dating back to the introduction of the League Division Series in 1981 and 1995) have gone on to win the series in over 72% of historical instances. When the leading team plays Game 4 in their home stadium, that win rate climbs to nearly 77%.
Understanding Series Leverage Index (SLI)
In Sabermetric analysis pioneered by Tom Tango and FanGraphs, Leverage Index (LI) measures the importance of a single plate appearance or pitch. Series Leverage Index (SLI) scales this concept to the macro level: how much does the result of tonight's game shift the franchise's probability of surviving the October gauntlet?
In Game 4 of a 2-1 series, the trailing team (the Brewers) faces elimination: a loss drops their win probability to 0%, while a win preserves life and restores a 50/50 Game 5 winner-take-all showdown. Because their entire season hinges on every pitch, Game 4 carries an SLI of over 2.1 (more than double the baseline stakes of Game 1).
The Markov Property in October Baseball
A playoff series is naturally modeled as an absorbing Markov chain. Each game is a distinct Bernoulli trial where the win probability p is conditioned on three critical factors:
- Venue & Last Licks: Home teams bat last, avoiding sudden-death bottom-half scenarios in extra innings and tailoring bullpen usage to maintain ties.
- Starting Pitching Rest Decay: In short series, teams that finish early reset their rotation aces for Game 1 of the League Championship Series (NLCS/ALCS), creating downstream cascade equity.
- Bullpen Leverage Burn: A team down 1-2 must deploy their highest-leverage relievers in high-stress innings, often creating compounding fatigue for a hypothetical Game 5.
Postseason Analytics FAQ
What happens historically when an MLB team takes a 2-1 lead?
Across all MLB best-of-5 series through modern postseason history, teams with a 2-1 lead have won the series approximately 72.8% of the time. When playing Game 4 at home (like San Diego at Petco Park in a 2-2-1 format), the 2-1 leader closes it out in Game 4 roughly 51% of the time, and wins Game 5 if forced another 23% of the time.
How does the 2-2-1 format differ from the 2-3-2 format?
The Division Series (NLDS/ALDS) uses a 2-2-1 structure: the higher seed hosts Games 1, 2, and 5, while the lower seed hosts Games 3 and 4. This means if the lower seed steals one of the first two games on the road (entering Game 3 tied 1-1), they gain home-field advantage for both pivotal middle games. The LCS and World Series use a 2-3-2 format, giving the higher seed three straight potential home elimination opportunities.
What is the mathematical definition of Series Leverage Index?
SLI is calculated as: SLI = (P(Series Win | Win) - P(Series Win | Loss)) / Average_Game_Swing. In a balanced best-of-5, the average swing in Game 1 is approximately 25 percentage points (75% to 25%). In an elimination game where the swing is 50 percentage points (100% to 50%), the leverage doubles to 2.0+.
How does this calculator account for pitching matchups?
The Pitching Matchup slider shifts the baseline single-game win probability for the upcoming match. For instance, if San Diego sends an elite strikeout ace with a 2.50 FIP against a fatigued bullpen game, the single-game expectation adjusts upward by 4% to 8%, immediately feeding into the recursive binomial solver.