Series Comebacks – What are the Odds?

Teams have trailed 3-1 in a series and won 20 of 229 times, 8.7% of the time. Not all 3-1 deficits, however, are created equally. For example, Washington should have a better than 8.7% chance to come back from a 3-1 deficit (thanks Puck Report).

How do you calculate what a team’s chances are to come back from a series deficit (besides looking at their series odds at a sportsbook)?

Let’s use the Washington-Rangers series as an example:

Step 1: Figure out the odds on Washington to win each game.

I recommend Covers. They have the historical odds and results of games dating back to the 1995-1996 season. Also the line for tomorrow’s game is available at any online sportsbook.

Game 5 line: Washington -185

Game 6 line (estimate based on earlier games): Washington -120

Game 7 line (estimate based on earlier games): Washington -195

Step 2: Convert those odds from American into European Style odds.

American odds use + and – to indicate whether a team is a favorite or an underdog. European odds use decimals, and are the same style of odds used in Canadian sports lottery parlay games such as proline. You can find an odds converter here.

Game 5 odds: 1.54

Game 6 odds: 1.83

Game 7 odds: 1.51

Step 3: Multiply the odds together.

Since all three events need to happen in order for the Caps to win the series, odds are determined by multiplying each event.

1.54*1.83*1.51 = 4.26= 1 in 4.26

Step 4: Use the odds converter to determine the percentage chance of an event with odds of 4.26 happening.

4.26 = 23.47%

Summary

Washington’s % Chance to win the series = 1/(odds win G5 * odds win G6 * odds win G7)

OR

1/(1.54*1.83*1.51)= 23.47%.