March Madness Update

Ever since reading Stanford Wong’s ‘Sharp Sports Betting,’ I’ve been interested in the relationship between a team’s chances of winning and its seed in March Madness. Such information comes in handy for proposition bets like “Will a 14-16 win at least one game?” and “Will a number 1 seed win the tournament?”

Round 2

Let’s start with the results after the first round, as shown in the following table. The table shows how many teams of each seed survived in 2023 as well as the average for the 37 historical seasons from 1985 to 2022. Reminder that in 2020 there was no season, for obvious reasons.

Seed 2023 Average
1 3 3.97
2 3 3.70
3 4 3.41
4 3 3.16
5 4 2.57
6 3 2.46
7 3 2.43
8 2 2.03
9 2 1.97
10 1 1.57
11 1 1.54
12 0 1.43
13 1 0.84
14 0 0.59
15 1 0.30
16 1 0.03
Total 32 32.00
 

What really jumps out is only three number 1 seeds survived. Prior to this season, in 148 games of a 1 vs. 16 seed, the 1 seed won 147 times. This year marks only the second time in history a #16 seed won.

All things considered, the average surviving seed was 5.97, compared to a historical average of 5.84. So, the underdogs are off to a good start, in large part because of that 16-seed win (Farleigh Dickenson over Purdue).

Round 3

The following table shows how many teams of each seed survived to make round 3 in 2023 as well as the average for the 37 historical seasons from 1985 to 2022.

Seed 2023 Average
1 2 3.41
2 2 2.51
3 3 2.08
4 2 1.89
5 2 1.35
6 1 1.19
7 1 0.76
8 1 0.41
9 1 0.19
10 0 0.65
11 0 0.68
12 0 0.59
13 0 0.16
14 0 0.05
15 1 0.08
16 0 0.00
Total 16 16.00
 

What stands out to me is another #1 seed was knocked out (Arkansas beating Kansas), leaving only 2. As you can see, historically 3.41 #1 seeds make it to round 3. All things considered, the average seed making it to round 3 is 4.88, compared to a historical 4.57. So, the underdogs continue to outperform history.

Round 4

The following table shows how many teams of each seed survived to make round 4 in 2023 as well as the average for the 37 historical seasons from 1985 to 2022.

Seed 2023 Average
1 0 2.73
2 1 1.81
3 2 1.00
4 1 0.59
5 2 0.27
6 1 0.43
7 0 0.27
8 0 0.24
9 1 0.11
10 0 0.24
11 0 0.22
12 0 0.05
13 0 0.00
14 0 0.00
15 0 0.03
16 0 0.00
Total 8 8.00
 

The remaining two #1 seeds both get knocked out in round 3. Normally, as you can see, 2.73 make it to round 4. “Has this ever happened before?”, you might ask. Yes, in 2006 and 2011. All things considered, the average seed making it to round 4 is 4.63, compared to a historical 3.29. The underdogs continue to impress!

Round 5

The following table shows how many teams of each seed survived to make round 5 in 2023 as well as the average for the 37 historical seasons from 1985 to 2022.

Seed 2023 Average
1 0 1.62
2 0 0.86
3 0 0.46
4 1 0.35
5 2 0.19
6 0 0.08
7 0 0.08
8 0 0.16
9 1 0.03
10 0 0.03
11 0 0.14
12 0 0.00
13 0 0.00
14 0 0.00
15 0 0.00
16 0 0.00
Total 4 4.00
 

All things considered, the average seed making it to round 5 is 5.75, compared to a historical 2.86. “Does this set a new record for the lowest average seed to make it this far?”, you might ask. No, only one year had a lower average seed of 6.5, in 2011.

Round 6

The following table shows how many teams of each seed survived to make round 5 in 2023 as well as the average for the 37 historical seasons from 1985 to 2022.

Seed 2023 Average
1 0 1.00
2 0 0.35
3 0 0.30
4 1 0.08
5 1 0.08
6 0 0.05
7 0 0.03
8 0 0.11
9 0 0.00
10 0 0.00
11 0 0.00
12 0 0.00
13 0 0.00
14 0 0.00
15 0 0.00
16 0 0.00
Total 2 2.00
 

The seeds to make it to the championship game are a 4 and 5, for an average of 4.5. Historically, the average to his point has been 2.35. You might wonder, “Is this a record for the lowest higher seeded team by this point?” No. In 2014 the championship game was between a 7 and 8 seed.

Round 7

In 2023, a #4 seed, the University of Connecticut, won. This has happened only once before, in 1997. The average seed to win, historically, was 1.92. In conclusion, hurray for UConn and all the underdogs!

Average Wins by Seed

The following table shows my updated statistics for the average games won for any given team by seed.

Seed Average wins
1 3.29
2 2.32
3 1.85
4 1.55
5 1.16
6 1.07
7 0.90
8 0.74
9 0.59
10 0.61
11 0.63
12 0.51
13 0.25
14 0.16
15 0.11
16 0.01
 

Perfect Bracket

After updating my spreadsheet with the 2023 season, my probability of a perfect bracket is 1 in 1,411,767,179. This assumes a strategy of always picking the higher seeded team. In the case they are equally seeded, then pick randomly.

For any given employee of Warren Buffet, this brings the expected value of this $1,000,000 per year for a perfect bracket to 11 cents, assuming a remaining life expectancy of 40 years. Assuming 377,000 employees, the expected total cost to Mr. Buffet, per year, is $399.