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Ask The Wizard #398

Now that the excitement of March Madness has concluded, have you recalibrated your chances of submitting a flawless bracket, along with the average wins based on seed ranking?

anonymous

I appreciate the reminder. My fundamental approach when completing a bracket involves consistently selecting the team with the higher seed (essentially, the one with a lower seed number). When faced with a match-up between two 1 seeds, I prefer to make a random choice. Incorporating a 39th year into my March Madness statistics, here are the probabilities associated with achieving a perfect bracket.

  • 1 seed beats 16 seed = 98.72%
  • 2 seed beats 15 seed = 92.31%
  • 3 seed beats 14 seed = 85.26%
  • 4 seed beats 13 seed = 78.85%
  • 5 seed beats 12 seed = 64.74%
  • 6 seed beats 11 seed = 60.9%
  • 7 seed beats 10 seed = 61.54%
  • 8 seed beats 9 seed = 50%
  • 1 seed beats 8 seed = 78.75%
  • 4 seed beats 5 seed = 55.42%
  • 3 seed beats 6 seed = 60%
  • 2 seed beats 7 seed = 70.79%
  • 1 seed beats 4 seed = 71.01%
  • 2 seed beats 3 seed = 60.66%
  • 1 seed beats 2 seed = 55.07%
  • 1 seed beats 1 seed = 50%

A participant must accurately predict the outcome of each matchup, apart from the 1 vs. 1 scenarios, a total of four times. During the fifth and sixth rounds, there will be three games featuring 1 seeds against each other, which also need to be correctly guessed.

Ultimately, the likelihood of correctly picking all 63 games following this strategy stands at 1 in 70,166,868,878.

In response to your other inquiry, here is the anticipated number of wins for each team, arranged by seed. For instance, a #5 seed can typically be expected to secure about 1.153846 victories.

  1. 3.301282
  2. 2.320513
  3. 1.839744
  4. 1.557692
  5. 1.153846
  6. 1.057692
  7. 0.897436
  8. 0.730769
  9. 0.596154
  10. 0.602564
  11. 0.653846
  12. 0.50641
  13. 0.25
  14. 0.160256
  15. 0.108974
  16. 0.012821

What is the Prime Number Theorem?

anonymous

The Prime Number Theorem offers several intriguing insights:

  1. On average, the spacing between prime numbers near the value of n is roughly ln(n).
  2. Additionally, an approximation of the quantity of primes less than n is expressed as n/ln(n).

To explore the latter claim, I developed a program to tally the number of primes from one million up to ten million. The table below lists these counts alongside the projections derived from the aforementioned formula. The rightmost column illustrates the ratio of estimated values to the actual prime counts.

Primes

Maximum
Number
Total
Primes
Estimate Ratio
1,000,000 78,498 72,382 0.9220925
2,000,000 148,933 137,849 0.9255754
3,000,000 216,816 201,152 0.9277527
4,000,000 283,146 263,127 0.9292967
5,000,000 348,513 324,150 0.9300950
6,000,000 412,849 384,436 0.9311788
7,000,000 476,648 444,122 0.9317618
8,000,000 539,777 503,304 0.9324303
9,000,000 602,489 562,053 0.9328845
10,000,000 664,579 620,421 0.9335545

As demonstrated, the ratio of primes below ten million is 93.4% of the actual count. Nevertheless, this ratio tends to decrease as you expand the range of numbers being evaluated.

For further details, visit the relevant Wikipedia page on this topic. Prime Number Theorem .

What are some of the least expensive blunders to make in blackjack?

gunbj

To begin, we’ll outline some basic assumptions regarding the rules. I will base these on what appears to be the most prevalent ruleset utilized in the U.S.

  • Six decks
  • Dealer hits soft 17
  • Double after split allowed
  • Surrender not allowed
  • Players have the option to re-split their hands up to four times, which includes aces.

With that in mind, the following list presents the top 20 nearest calls based on the first two cards dealt to the player and the dealer's visible card.

Closest Decisions in Blackjack

Player
Cards
Dealer
Up Card
Best
Play
Second
Best Play
EV 1st
Best Play
EV 2nd
Best Play
Difference
9,7 10 HS-0.535392-0.536809 0.001417
7,A 2 DS 0.116262 0.113110 0.003152
2,A 5 DH 0.141030 0.137618 0.003412
4,A 4 DH 0.065278 0.060757 0.004521
6,A 2 HD-0.000274-0.004882 0.004608
10,2 4 SH-0.205906-0.210664 0.004758
7,2 2 HD 0.073913 0.067870 0.006043
10,6 10 HS-0.534676-0.540954 0.006278
5,4 2 HD 0.075786 0.068039 0.007747
6,3 2 HD 0.075331 0.067378 0.007953
8,4 3 HS-0.233324-0.241586 0.008262
7,5 3 HS-0.232183-0.240505 0.008322
9,2 ADH 0.115609 0.107036 0.008573
3,3 2 PH-0.129464-0.139266 0.009802
8,A 6 DS 0.462089 0.452220 0.009869
9,3 3 HS-0.237301-0.248068 0.010767
8,3 ADH 0.118796 0.107445 0.011351
3,3 8 HP-0.219182-0.230664 0.011482
8,4 4 SH-0.201386-0.213959 0.012573
9,3 4 SH-0.202651-0.215698 0.013047

This topic was raised and deliberated on my forum at Wizard of Vegas .