I'm interested here in a flat rate game, but this idea could be easily be extended to escalating games as well.
I want to quantify the contribution that cashing in a set of cards will have on the number of armies a player will receive in his next turn. This contribution is based on the number of cards currently held by a player.
Let:
T(n) be total expected armies player will receive in his next turn when holding n cards.
B be bonus armies due for owning countries (country owning bonus).
b(d) be bonus armies for owning d countries (basic allotment)
d be countries held by a player.
c be armies due for owning a group of countries (continent bonus).
m be consecutive missed turns by player.
E(n) be expected armies for cashing in a set of cards (card cashing bonus).
e(n) be expected armies for cashing in a particular color set when holding n cards (card set bonus).
H(n) be expected armies for owning countries specified on cards cashed in (country card bonus).
h(n) be probability player has set when holding n cards.
D be total number of countries on game map.
Then, total expected armies when holding n cards is sum of country owning bonus and card cashing bonus:
T(n) = B + E(n)
Where, country owning bonus is sum of basic allotment and continent bonus adjusted by missed turn multiplier:
B = (b + c) * (m + 1)
Basic allotment is 3 armies plus 1 for every additional multiple of 3 armies held above 12:
b(d < 12) = 3
b(d >= 12) = floor (d / 3)
Card cashing bonus is sum of card set bonus and country card bonus:
E(n) = e(n) + H(n)
Expected card set bonus when holding n cards:
- Code: Select all
e(0 < n < 3) = 0 // card set not possible
e(3) = 2.889 // 10*(18/81)+(4+6+8)*(3/81); 3^4=81 possibilities, 18+(3*3)=27 sets
e(4) = 5.333 // 10*(18/54)+(4+6+8)*(6/54); 81-27=54 possibilities, 18+(3*6)=36 sets
e(5) = 7.333 // 10*(6/18)+(4+6+8)*(4/18); 81-27-36=18 possibilities, 6+(3*4)=18 sets
Expected country card bonus when holding n cards (3 cards each worth 2 armies if country named on card cashed is owned by player):
H(n) = 3 * 2 * h(n) * (d / D)
Expected probability of having a set when holding n cards:
[Edit]
- Code: Select all
h(0 < n < 3) = 0 // card set not possible
h(3) = 0.333 // 27/81
h(4) = 0.667 // 36/54
h(5) = 1 // 18/18
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Examples assuming the Classic map with 42 total countries:
1) Player owns 15 countries, owns North America and South America, and holds 3 cards:
T(3) = (5 + 7) * (1 + 0) + 2.889 + 3 * 2 * 0.333 * (15 / 42) = 15.6 new armies next turn.
He will receive at least 12, at most 28, on average 15.6 new armies next turn.
The least you can receive in flat rate when cashing a set is 4 (for red), the most is 16 (10 for mixed, and 6 for owning all three countries specified on the cards).
2) Player owns 13 countries, owns Australia, and holds 4 cards:
T(4) = (4 + 2) * (1 + 0) + 5.333 + 3 * 2 * 0.778 * (13 / 42) = 12.8 new armies next turn.
He will receive at least 6, at most 22, on average 12.8 new armies next turn.
3) Player owns 8 countries, owns no continents, missed two turns, and holds 5 cards:
[Edit]
T(5) = (3 + 0) * (2 + 1) + 7.333 + 3 * 2 * 1 * (8 / 42) = 14.5 new armies next turn.
[/Edit]
He will receive at least 10, at most 22, on average 14.5 new armies next turn.