Super Bowl Squares: What are the Odds by Minute? Quarter? Final?

Many people love to gamble on sports. A popular way of betting on the Super Bowl is called Super Bowl Squares. The way it works is simple: 1. There are 100 squares in a 10x10 grid. Participants purchase one or more squares in the grip. 2. The numbers 0-9 are assigned to each row (Team A) and column (Team B) of the grid. 3. At the end of every "time unit" the ones digit of each team's score determines the winner. So if the score is 13-17, 13-7, or 3-7, the (3,7) square pays out.

Commonly there is a payout either at the end of the game or at the end of each quarter. Both of these cases have been analyzed by others (e.g. 538 and the Harvard Sports Analysis Collective). However, at this year's Super Bowl I was talking to someone who was in a Squares pool that paid out based on the score at the end of every minute!

This is unusual, or at least a newer development, and I couldn't find any analysis of it online.

I calculated the payout on a $1 bet (assuming equal payout per time period) for each of minute, quarter, and final score based on the last 20 Super Bowls (XXXV-LIV). I treated teams symmetrically, so, for example, the payouts for 3-7 and 7-3 were averaged.

As you can see, switching from Quarters to Minutes increases the skew towards the best square 0-0. More than a fifth of minutes in the last 20 Super Bowls had scores with zeroes as the trailing digits!

Notes

1. Scoring data from https://www.pro-football-reference.com/
2. Code available upon request