Let's do the math: Witcher/Crones
I have been wondering about the precise percentage to end with a dead card in hand while playing Witchers or Crones.
Since their use fills 3 valuable Silver slots, I made some math about how useful they are.
I'm writing my calculations here so that people skilled in math can correct me if I made a mistake.
Question: How much is the percentage chance to get an opening draw of 0,1,2 or 3 Witcher cards in a deck of 25?
The deck is composed by 25 cards, but we start drawing 10 of them, so the chance to draw a single particular card is 10/25.
Of course, it changes a little when we want to get 3 particular cards all together.
Let's start with the chance to get all 3 witchers, assuming we 'fix' Eskel on draw slot 1.
We have 10 chances out of 25 to draw him, which means that when we want to draw the next one, Lambert, we haven't 10 draws anymore, they became 9 out of 24.
Next is Vesemir, where we have the previous two draws 'reserved' for his pupils, se he gets 8 out of 23 chances to be drawn and to claim he's too old for that shit.
Since calculating multiple chances is a multiplication, we have:
(10/25) * (9/24) * (8/23) = 720 / 13800 (5.217%)
However, all 3 witchers are interchangeble and need no particular draw order, so the example above happens if we keep 'fixed' Eskel, followed by Lambert and Vesemir.
But no matter how we permute their order, as long as the result is getting 3 witchers out of 3,so we multiply the 'Eskel fixed"'s chance by 3 and get:
3 * [(10/25) * (9/24) * (8/23)] = 2160 / 13800 (15.65%)
Let's check now the other scenarios, for example the chance to get any 2 witchers out of 3.
We fix again the reliable Eskel in slot 1, resulting in the easy 10/25.
Next is Lambert, with the old 9/24.
Now it gets a little different, because for the next 8 draws Vesemir will have NOT to be chosen.
Which means that in the 3rd draw, we have 1 Vesemir out of 23 cards, adding a 22/23 multiplication.
Then we have 21/22, 20/21 and so on until we get 15/16.
To resume, we get this:
(10/25) * (9/24) * (22/23) * (21/22) * (20/21) * (19/20) * (18/19) * (17/18) * (16/17) * (15/16) =
(10/25) * (9/24) * [after simplifying] 15/23 = 1350 / 13800 (9,782%)
Again, we have to multiply by 3, because keeping Eskel fixed is not essential, so we get:
3 * [(10/25) * (9/24) * (15/23)] = 4050 / 13800 (29.35%)
But what if we wanted just a single witcher?
We start with the usual 10/25, but from the second draw to the tenth we have 2 undesired cards, so we get:
(10/25) * (22/24) * (21/23) * (20/22) * (19/21) * (18/20) * (17/19) * (16/18) * (15/17) * (14/16) =
(10/25) * [after simplifying] (15*14)/(24*23) = 2100 / 13800 (15.217%)
Again, we multiply by 3:
3 * [(10/25) * (15/24) * (14/23)] = 6300 / 13800 (45.65%)
And if we wanted no witcher at all?
We can simply sum the chances of all scenarios above put together where we considered the presence of a witcher and subtract it from the total:
13800 - (2160+4050+6300) = 1290 (9.35%)
Now, let's verify.
Chance Percentage
Case 1: Three Witchers = 2160 15.65 %
Case 2: Two Witchers = 4050 29.35 %
Case 3: One Witcher = 6300 45.65 %
Case 4: Zero Witchers = 1290 9.35 %
TOTAL = 13800 100.00 %
It seems to work ^_^.
I'm trying now to calculate the exact chance once the mulligan has been used, but I'd like first to get some feedback to be sure I'm not wrong.
I have been wondering about the precise percentage to end with a dead card in hand while playing Witchers or Crones.
Since their use fills 3 valuable Silver slots, I made some math about how useful they are.
I'm writing my calculations here so that people skilled in math can correct me if I made a mistake.
Question: How much is the percentage chance to get an opening draw of 0,1,2 or 3 Witcher cards in a deck of 25?
The deck is composed by 25 cards, but we start drawing 10 of them, so the chance to draw a single particular card is 10/25.
Of course, it changes a little when we want to get 3 particular cards all together.
Let's start with the chance to get all 3 witchers, assuming we 'fix' Eskel on draw slot 1.
We have 10 chances out of 25 to draw him, which means that when we want to draw the next one, Lambert, we haven't 10 draws anymore, they became 9 out of 24.
Next is Vesemir, where we have the previous two draws 'reserved' for his pupils, se he gets 8 out of 23 chances to be drawn and to claim he's too old for that shit.
Since calculating multiple chances is a multiplication, we have:
(10/25) * (9/24) * (8/23) = 720 / 13800 (5.217%)
However, all 3 witchers are interchangeble and need no particular draw order, so the example above happens if we keep 'fixed' Eskel, followed by Lambert and Vesemir.
But no matter how we permute their order, as long as the result is getting 3 witchers out of 3,so we multiply the 'Eskel fixed"'s chance by 3 and get:
3 * [(10/25) * (9/24) * (8/23)] = 2160 / 13800 (15.65%)
Let's check now the other scenarios, for example the chance to get any 2 witchers out of 3.
We fix again the reliable Eskel in slot 1, resulting in the easy 10/25.
Next is Lambert, with the old 9/24.
Now it gets a little different, because for the next 8 draws Vesemir will have NOT to be chosen.
Which means that in the 3rd draw, we have 1 Vesemir out of 23 cards, adding a 22/23 multiplication.
Then we have 21/22, 20/21 and so on until we get 15/16.
To resume, we get this:
(10/25) * (9/24) * (22/23) * (21/22) * (20/21) * (19/20) * (18/19) * (17/18) * (16/17) * (15/16) =
(10/25) * (9/24) * [after simplifying] 15/23 = 1350 / 13800 (9,782%)
Again, we have to multiply by 3, because keeping Eskel fixed is not essential, so we get:
3 * [(10/25) * (9/24) * (15/23)] = 4050 / 13800 (29.35%)
But what if we wanted just a single witcher?
We start with the usual 10/25, but from the second draw to the tenth we have 2 undesired cards, so we get:
(10/25) * (22/24) * (21/23) * (20/22) * (19/21) * (18/20) * (17/19) * (16/18) * (15/17) * (14/16) =
(10/25) * [after simplifying] (15*14)/(24*23) = 2100 / 13800 (15.217%)
Again, we multiply by 3:
3 * [(10/25) * (15/24) * (14/23)] = 6300 / 13800 (45.65%)
And if we wanted no witcher at all?
We can simply sum the chances of all scenarios above put together where we considered the presence of a witcher and subtract it from the total:
13800 - (2160+4050+6300) = 1290 (9.35%)
Now, let's verify.
Chance Percentage
Case 1: Three Witchers = 2160 15.65 %
Case 2: Two Witchers = 4050 29.35 %
Case 3: One Witcher = 6300 45.65 %
Case 4: Zero Witchers = 1290 9.35 %
TOTAL = 13800 100.00 %
It seems to work ^_^.
I'm trying now to calculate the exact chance once the mulligan has been used, but I'd like first to get some feedback to be sure I'm not wrong.