Showing posts with label odds. Show all posts
Showing posts with label odds. Show all posts

Saturday, June 20, 2026

High Rollers: When Only Even Numbers Remain – Game Strategy

High Rollers: When Only Even Numbers Remain – Game Strategy



Introduction



In the famous game show High Rollers, which aired from 1975-1980, hosted by Alex Trebek and then again from 1987-1988 hosted by Wink Martindale. The main objective of the game is to eliminate numbers 1 through 9 by rolling dice.



On the game show, there are two rounds*. On the main game, two opponents play against each other. The winner goes on to the Big Numbers where the winner tries to clear all the numbers.



* There were variants, but this was prevailing game modes.



For detailed information: https://en.wikipedia.org/wiki/High_Rollers




Just Even Numbers Left: 2, 4, 6, and 8


From this point, only rolls with even sums are valid. The strategy changes depending on what round is being played.


In a two-player game: You either win by either rolling the last number off the board or getting your opponent to roll an unplayable number. As the game goes on, the chance of rolling an unplayable number increase.


In the Big Numbers bonus round: To win the big prize, typically a $ 10,000 cash jackpot, the only you win is to clear all the numbers.


Ways to roll even numbers:


2: 1,1

4: 1,3; 2,2; 3,1

6: 1,5; 2,4; 3,3; 4,2; 5,1

8: 2,6; 3,5; 4,4; 5,3; 6,2

10: 4,6; 5,5; 6,4

12: 6,6


If both dice has the same number, i.e. 2,2, it is considered a double and it wins the player an Insurance card, which counts as a free roll. At worst, rolling doubles acts as a “roll again”.


With a board consisting of the even numbers 2, 4, 6, and 8, the best way


Roll

Main Game: Against an Opponent

During the Big Numbers Bonus Round

2

Only one move: remove the 2

Only one move: remove the 2

4

Only one move: remove the 4. 4 becomes an unplayable roll.

Only one move: remove the 4. 4 becomes an unplayable roll.

6

Remove the 2 and 4. This eliminates 2, 4, 10, and 12 as valid rolls, leaving only the 6 and 8.

Remove the 6. This leaves 2, 4, and 8. All even rolls are still good. A roll of 6 can eliminate the 2 and 4 the next roll.

8

Remove the 2 and 6. This eliminates the 2, 6, and 10, leaving only the 4, 8, and 12 (12 wins the game).

Remove the 8. This leaves 2, 4, and 6. All even rolls are still good. A roll of 8 can eliminate the 2 and 6 the next roll.

10

Remove the 4 and 6. This leaves 2, 8, and 10 as valid rolls on the next turn (10 wins the game). The chance of rolling a 2, 8, or 10 is 1/6 (≈ 16.7%).

Remove 2 and 8. This leaves 4, 6, and 10 as valid rolls on the next turn (10 wins the game). The chance of rolling a 4, 6, or 10 is 2/9 (≈ 22.2%).

12

Remove on 2, 4, and 6. This leaves only the 8. Chance of rolling 8 is 5/36 (≈ 13.9%).

Remove the 4 and 8. This leaves the 2 and 6. A roll of 8 can eliminate both the 2 and 6 on the next roll. The chance of rolling a 2, 6, and 8 is 11/36 (≈ 30.6%).


Source

“High Rollers” Wikipedia. Edited November 10, 2025. Retrieved February 14, 2026. https://en.wikipedia.org/wiki/High_Rollers


Eddie


All original content copyright, © 2011-2026. Edward Shore. Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited. This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author.

Sunday, October 1, 2023

HP 15C and TI-60: The Lottery Probability Function

HP 15C and TI-60:  The Lottery Probability Function



The Lottery Probability Function


The expression, of what I call the Lottery Probability Function:


prob =  nCr(k, b) × nCr(n-k, k-b) ÷ nCr(n, k)


where:


*  nCr is the combination function.  nCr(x,y) = x! ÷ (y! × (y - x)!)

*  n = the number of total balls in the lottery

*  k = the number of balls drawn

*  b = the number of balls your ticket matches

*  prob = probability 


Lottery odds are often stated as "1 in number" instead of decimal form.  The number is the statement "1 in number" is 1/p.   For example, "1 in 5" means that the probability is 1/5 or 0.20.  (20%)



HP 15C (Emulator) Program Code


Program Size:

19 steps, 30 bytes


Store before running label A:

R1 = n

R2 = k

R3 = b



Step : Step Code : Key

001 : 42,21,11 : LBL A

002 : 45, 2 : RCL 2

003 : 45, 3 : RCL 3

004 : 43,40 : Cy,x

005 : 44, 0 : STO 0

006 : 45, 1 : RCL 1

007 : 45,30, 2 : RCL- 2

008 : 45, 2 : RCL 2

009 : 45,30, 3 : RCL- 3

010 : 43,40 : Cy,x

011 : 44,20, 0 : STO× 0

012 : 45, 1 : RCL 1

013 : 45, 2 : RCL 2

014 : 43,40 : Cy,x

015 : 44,10, 0 : STO÷ 0

016 : 45, 0 : RCL 0

017 : 15 : 1/x

018 : 44, 0 : STO 0

019 : 43, 32 : RTN


Caution:  HP 15C Limited Edition.  It is a known bug when the combination (Cy,x) and permutation (Py,x) are run multiple times, the display flashes as if a overflow error occurs.  The program otherwise runs fine (with the examples I tested - 2011/04/15 firmware).   

To eliminate unnecessary flashing, use the following key sequence:

[ GTO ] ( A ) [ R/S ]


Full a list of known bugs, as compiled by Katie Wasserman, click here:

https://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=1089



TI-60 (Programmable Scientific/Advanced Scientific) Program Code


57 steps.   No commands are merged.  


For the combination (and permutation) functions, the number must be formatted as the following: nnn.rrr


The command sequence INV EE cancels scientific notation display.  


Step : Step Code : Key

01 : 71 : RCL

02 : 02 :  2

03 : 85 : +

04 : 03 : 3

05 : 55 : ÷

06 : 01 : 1

07 : 42 : EE

08 : 03 : 3

09 : 95 : =

10 : 80 : nCr

11 : 61 : STO 

12 : 00 : 0

13 : 71 : RCL

14 : 01 : 1

15 : 85 : +

16 : 71 : RCL

17 : 02 : 2

18 : 55 : ÷

19 : 01 : 1

20 : 42 : EE

21 : 03 : 3

22 : 95 : =

23 : 80 : nCr

24 : 61 : STO

25 : 55 : ÷

26 : 00 : 0

27 : 71 : RCL

28 : 01 : 1

29 : 75 : -

30 : 71 : RCL

31 : 01 : 1

32 : 85 : +

33 : 53 : (

34 : 71 : RCL

35 : 02 : 2

36 : 75 : -

37 : 71 : RCL

38 : 03 : 3

39 : 54 : )

40 : 55 : ÷

41 : 01 : 1

42 : 42 : EE

43 : 03 : 3

44 : 95 : =

45 : 80 : nCr

46 : 61 : STO

47 : 65 : ×

48 : 00 : 0

49 : 71 : RCL

50 : 00 : 0

51 : 76 : 1/x

52 : 61 : STO

53 : 00 : 0

54 : 12 : INV

55 : 42 : EE

56 : 13 : R/S

57 : 22 : RST



Examples


1.  49 balls and 6 are drawn.    Set up variables:  R1 = n =  49 and R2 = k = 6.


R3 = b = 6:  1 in 13,983,816

R3 = b = 5:  1 in 54,200.83721

R3 = b = 4:  1 in 1,032.3396899


2.  52 balls and 6 are drawn.  Set up variables:  R1 = n = 52 and R2 = k = 6.


R3 = b = 6:  1 in 20,358,520

R3 = b = 5:  1 in 73,762.75362

R3 = b = 4:  1 in 1,311.337842


Note that this function does not take the power ball, which only 1 is drawn in addition to the lottery balls, into account.   If you have a power ball of p balls, we can calculate the odds as follows:


You match the power ball:

prob = 1 ÷ p × nCr(k, b) × nCr(n-k, k-b) ÷ nCr(n, k)


1 in odds:  1/prob


You don't match the powerball:

prob = (p - 1) ÷ p × nCr(k, b) × nCr(n-k, k-b) ÷ nCr(n, k)


1 in odds:  1/prob



Source:

"Lottery mathematics".  Wikipedia.  Last edited July 10, 2023.  Retrieved July 23, 2023.  https://en.wikipedia.org/wiki/Lottery_mathematics


Eddie 


All original content copyright, © 2011-2023.  Edward Shore.   Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited.  This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author. 


Earth's Radius by Latitude

Earth's Radius by Latitude Introduction: Calculating the Earth’s Radius In quick, general calculations, we assume that the...