Stolen Base Probability Calculator

The question behind the result

The requested output is estimated event probability. The page is intended to estimate the chance of at least one stolen base from opportunities and a per-opportunity rate. As a practical check, another period or grading basis is a different question.

Opportunities depend on reaching base, runner intent, pitcher delivery, catcher quality, score, and inning.

Checks the arithmetic cannot perform

A rate from another runner or game state should not be transferred without adjustment.

When using the result, starting pitcher, bullpen workload, park, weather, batting order, and handedness should be current for the scheduled game.

On this page, a pitcher or lineup change can invalidate a projection before the posted price visibly moves.

How to source the fields

Expected opportunities records number of relevant attempts or chances.

Probability per opportunity is a separate input defined as estimated chance of at least one stolen base on each opportunity.

Events needed is a separate input defined as threshold required for the wager.

Within this calculation, do not copy a sample default into a live case without checking its source.

After documenting estimated event probability, the First Five Innings Run Line can answer another question.

Calculation method and assumptions

Formula: probability = binomial chance of reaching the event threshold.

The model treats attempts or scores as repeated events over the selected horizon.

Dependence and changing game state can widen the real range.

For this market, every change can be traced to a visible field or the formula.

Comparing two plausible cases

Change Expected opportunities while leaving the rate fixed.

Under the entered assumptions, test the rate in its own case if that source is uncertain.

For rare events, review whether the rate can remain stable and opportunities independent.

To compare pitcher walks allowed separately, open the Pitcher Walks Allowed after saving this baseline.

Worked numbers

For the saved case, a separate input set allows inspection without overwriting the baseline.

For the Stolen Base Probability Calculator, the sample changes the starting values so the calculation can be followed without implying that the numbers are representative.

• Expected opportunities: 2 opportunities
• Probability per opportunity: 12.96%
• Events needed: 1 event

Applying the Stolen Base Probability rule: probability = binomial chance of reaching the event threshold.

Fair odds is +313. Expected events is 0.26. Probability below threshold is 75.76%.

For this estimated event probability example, recalculate the example after any code or formula change so the page retains a visible arithmetic check.

As a practical check, keep the example separate from the saved market case.

From output to market comparison

Read the result with the assumed opportunity count.

A stable rate cannot compensate for poor volume.

For this comparison, a difference should survive one reasonable adverse case.

Where the method can break

Opportunities are treated as independent with a constant rate.

For the saved case, check listed-pitcher conditions, innings covered, postponement treatment, official scoring, and extra innings.

At this stage, the page cannot determine whether a sportsbook applies a settlement exception.

Keep this model focused on estimated event probability. Use the Home Run Probability for that separate calculation.

What to save with the result

Under the entered assumptions, keep event identity and timestamp beside estimated event probability.

Store estimated event probability with event, selection, compared line, time, and source for Expected opportunities.

For this market, a new format or settlement scope deserves a newly named case.

Market compatibility questions