Stolen Base Probability Calculator

Before interpreting the headline number

Estimate the chance of at least one stolen base from opportunities and a per-opportunity rate. Read estimated event probability within the event period entered here, because another baseball market may settle differently; retain the original result for comparison.

Starting pitcher, bullpen workload, park, weather, batting order, and handedness information must be current for the scheduled game. Settlement and data scope matter here because listed pitchers, official scoring, innings requirements, and postponement rules can determine whether the wager stands.

Match the fields to the wager

Expected opportunities opens this estimated event probability case; number of relevant attempts or chances; label it as observed, quoted, or projected.

For estimated event probability, enter Probability per opportunity on the printed basis because estimated chance of at least one stolen base on each opportunity; retain the original precision.

The Stolen Base Probability Calculator uses Events needed as a later input; threshold required for the wager; note when it was current.

The event snapshot is stale when a pitcher or lineup change can make a saved projection obsolete before the market price visibly moves; recheck the compared market as well.

A sample baseball market

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 events

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.

The arithmetic used here

The displayed rule is probability = binomial chance of reaching the event threshold.

For the Stolen Base Probability Calculator, the event is treated as repeated opportunities with a constant chance, and the qualifying binomial outcomes are added.

One explicit Stolen Base Probability Calculator assumption is Probability per opportunity, defined here as: estimated chance of at least one stolen base on each opportunity.

Preserve the precision supplied by the source during calculation, then round the reported answer only when presenting it; keep the compared line fixed while making that check.

A bettor comparing this output with home run probability can open the Home Run Probability and keep the assumptions distinct.

Market rules and model limitations

Opportunities are treated as independent with a constant rate.

Confirm listed-pitcher conditions, innings covered, postponement rules, and whether extra innings are included.

Interpret the Stolen Base Probability Calculator result only after checking that listed pitchers, official scoring, innings requirements, and postponement rules can determine whether the wager stands.

For first five innings run line, use the First Five Innings Run Line after saving the inputs behind estimated event probability.

Revisiting the calculation

Keep the market name, compared price, and calculation time beside estimated event probability; record when “Events needed” was current and whether it was measured or estimated.

Update the Stolen Base Probability Calculator if “Probability per opportunity” changes enough to affect the comparison; save the source beside the revised output.

The Pitcher Walks Allowed is relevant only if that separate result also affects the decision; it is not an extra input to estimated event probability.

Stolen Base Probability questions