Author: Jared Weber, Bradley Statistics Major

Game theory is known as a theoretical framework for conceiving social situations among competing players, more generally described as the study of strategy. It is primarily used in economics and social sciences but also has obvious applications in the world of sports. This series of articles will serve to study the framework of the Prospect League and help teams figure out how to optimize their journey to a championship title. 

The Prospect League regular season spans from May 31 to August 7 with all 17 teams being scheduled to play a total of 58 games. However, for the purposes of divisional round seeding in the playoffs, the season is split into two halves.  

Once the first half of the season is concluded On July 2nd, each of the 4 teams that are currently leading their division at that point are awarded as division champions and given the home-field slot in the divisional round. Then in the 2nd half of the season, the remaining teams in the division compete against each other to get the best 2nd half record so that they can play as the visitor to their division’s winner in the divisional round, thus completing the set-up of the 8-team playoff.  

The hosts of the conference championship and league championship are then determined by the teams’ full season record. 

With these established rules, we can now begin analysis on the first half of the season. Since outer-divisional records are not considered until the end of the season, we will analyze the CornBelter’s Wabash River division exclusively. 

For the purposes of simplicity and time, I will decide the outcome of every remaining game as if it were a coin flip. Although this completely disregards the talent and strategy that each Prospect League team pours into the games themselves, this decision will still allow me the find an answer to the main question of this project. 

How much more important is a divisional game from a non-divisional game? 

To tackle this question, I created the table below that first lays out the schedule and its results for the 4 teams, as well as counting how much games they will play. 

Next, I predict the likelihood that a team will have a certain number of wins based on a series of coin flips with their games remaining. 

Then, I copy this same table and apply the combined likelihood that all the other 3 teams will finish with a record below this team’s given win total. 

Lastly, I add the percentages under each win total together to estimate the full probability that a team will win their division. 

It should be noted this win probability metric still isn’t perfect as does not include the logic that divisional matchups are related to each other. It doesn’t understand that a divisional matchup can’t have both teams win or both teams lose. Nonetheless, with manual entries, I can provide daily updates with these win probability estimations to show the differences between divisional game results and non-divisional game results. 

Approximated Division Win Probability (DWP) Updated: June 27 

DWP Normal CornBelters (13-11): 10.7% 

DWP Added Non-Division Win: +7.8% DWP Lost Non-Division Loss: -7.7% 
DWP Added Terre Haute Win (June 23): +15.2% DWP Lost Terre Haute Loss (June 23): -14.8% 
DWP Added Danville Win (June 26): +20.4% DWP Lost Danville Loss (June 26): -16.0% 
DWP Added Springfield Win (July 2): +7.9% DWP Lost Springfield Loss (July 2): -7.8% 

DWP Springfield Lucky Horseshoes (11-12): 1.3% 

DWP Added Non-Division Win: +1.0% DWP Lost Non-Division Loss: -1.1% 
DWP Added Terre Haute Win (June 28): +1.0% DWP Lost Terre Haute Loss (June 28): -1.1% 
DWP Added Normal Win (July 2): +1.7% DWP Lost Normal Loss (July 2): -1.2% 

DWP REX Baseball (10-12): 0.3% 

DWP Added Non-Division Win: +0.4% DWP Lost Non-Division Loss: -0.3% 
DWP Added Danville Win (June 22 & June 27): +8.1% DWP Lost Danville Loss (June 22 & June 27): -4.5% 
DWP Added Normal Win (June 23): +9.7% DWP Lost Normal Loss (June 23): -8.2% 
DWP Added Springfield Win (June 28): +0.4% DWP Lost Springfield Loss (June 28): -0.3% 

DWP Danville Dans (15-10): 87.7% 

DWP Added Non-Division Win: +8.8% DWP Lost Non-Division Loss: -8.8% 
DWP Added Terre Haute Win (June 22 & June 27): +10.6% DWP Lost Terre Haute Loss (June 22 & June 27): -12.7% 
DWP Added Normal Win (June 26): +13.8% DWP Lost Normal Loss (June 26): -14.6% 

Sources:

Adam Hayes, Investopedia, “Game Theory”, https://www.investopedia.com/terms/g/gametheory.asp#:~:text=Investopedia%20%2F%20Katie%20Kerpel-,What%20Is%20Game%20Theory%3F,actors%20in%20a%20strategic%20setting.

Prospect League Playoff Format https://prospectleague.com/Content/playoffs

Leave a Comment