Re: [Rails-devel] 1835 presidency swap: Bug fix required (typos corrected)

[John D. G. <jd...@di...>]

Please use this version, I hit send too soon.

On 2015-08-21 13:18, Stefan Frey wrote:
> Another 1835 implementation issue:
> 
> President swaps are not easy to understand for newbies in any 18xx (you
> are not allowed to sell the president share, however you are allowed to
> tear it apart, virtually sell one half of it to the pool and then
> receive two shares by the new director, who gets the fixed director
> certificate, then the old director puts one of received shares into the
> pool and keeps the other).
> 
> In 1835 the 20% shares make selling the presidency even more interesting.
> 
> Selling the president certificate involves two steps of share movements:
> 
> A) Exchange the president certificate with shares from the new president
> 
> B) Move the remaining sold shares into the pool

I do not agree that these are separate steps.

> In 1835 both steps could include either 10% or 20% shares (PR: 5% or 10%
> shares)
> 
> Depending on what the president received in A) this might even change
> the possible options for B.
> 
> However it implies that the current president has to choose both A)
> which certificate to exchange with the new president and B) which
> certificate to put into the pool.
> 
> The current implementation only asks for A) and has some serious bugs in
> executing the share transfers.
> 
> I intend to fix those bugs before the next release, however I would ask
> if anyone has a different opinion on how it works for 1835?

I have not seen any case in which the current program gets it wrong (in
my view) -- however, I have not exhaustively tried every single case.

The following is the exact sequence of events I expect to happen in any
purchase or sale of stock (after any starting packet).  This applies to
all games, not just 1835.

In a purchase of stock:

(1) The player buys a certificate, not share(s).

(2) If the purchase causes a change of president, then the new president
exchanges one or more certificates (totaling the same number of shares
of that company) for the president's certificate, wherever it is.  (This
is a direct exchange between two players, unless the president's
certificate is in the bank pool, as it might be in 1829 (receivership)
or 1853v1 (when the company hasn't floated yet).)

(In 1835, if there is a choice, the outgoing president chooses which
certificate(s) he receives from among those in the new president's hand.
 I would follow this principle in any other game where any company has
non-presidential certificates of more than one size, if the rules do not
address the question.)

In a sale of stock:

(1) A sale that is going to cause a change of president may only be made
if some other player holds at least the number of shares that the
president's certificate contains.

(2) Except for the special case given in point (5), the player sells
certificate(s), not share(s).

(3) If the sale will cause a change of president, then one of the
certificate(s) sold must be the president's certificate.  Otherwise the
seller must retain the president's certificate.

(4) If the sale causes a change of presidency, then the new president
exchanges one or more certificates (totaling the same number of shares
of that company) for the president's certificate in the bank pool.  (The
outgoing president does not participate in this swap and does not have
any right to claim a certificate from the new president's hand.)

(5) A special case is where a player who holds only certificate(s) of
two or more shares each in that company wishes to sell a number or
shares that is not divisible by one of his certificates.  (For this
purpose "one share" is defined as the amount of the smallest certificate
that exists for that company.)

In this case the "fractional sale" may only be made if one of the
following is true in addition to point (1):

   A: The bank pool contains certificate(s) of the company in the right
sizes such that the seller can be given the correct number of shares
from the bank pool.  In this case the seller exchanges certificates with
the bank pool, and then point (4) applies.

   B: Statement A above is not true, but, the sale will cause a change
of presidency, and the bank pool and the old and new presidents' hands
together contain enough certificates of the company to give both the old
and new presidents the correct numbers of shares, with the new president
holding the president's certificate.  In this case a three-way swap of
certificates is performed.  If there is more than one correct way to
perform the swap, first the outgoing president chooses which
certificate(s) he gives up; then the new president chooses which
certificate(s) he gives up.

> Example:
> 
> In the attached save file OL has the following share distribution:
> 
> (Remark: this is from a replay of one of Bill Stoll's 1835 pbem games -
> see http://askwaltstollmd.com/bill/archive/1835zwolf/index.html
> Fun fact is that I played 1835 ftf with one of the players before he
> moved to the US)
> 
> Eyal: 50% (1 20% director, 1 20% share, 1 10% share)
> Marco: 40% (1 20% share, 2 10% share)
> Nick: 10% (1 10% share)
> 
> What are the possible scenarios for Eyal to sell his directorship?

If Eyal sells 10% (which does not change the presidency), he just moves
his 10% certificate to the bank pool.  Done.

If Eyal sells 20%, he moves the president's certificate to the bank
pool.  Then Marco takes it and chooses 20% (either one 20% or two 10%
certificates) to place in the bank pool.

If Eyal sells 30%, he moves the president's certificate and the 10%
certificate to the bank pool.  Then Marco takes the president's
certificate and chooses 20% (either one 20% or two 10% certificates) to
place in the bank pool.

If Eyal sells 40%, he moves the president's certificate and the 20%
certificate to the bank pool.  Then Marco takes the president's
certificate and chooses 20% (either one 20% or two 10% certificates) to
place in the bank pool.

If Eyal sells 50%, he moves all three of his certificates to the bank
pool.  Then Marco takes the president's certificate and chooses 20%
(either one 20% or two 10% certificates) to place in the bank pool.

[snip]
> Some special (hypothetical) cases:
> 
> A) No shares in Pool
> 
> Eyal: 40% (20%P + 20%)
> Marco: 20% (20%)
> 
> IPO: 40% (4 10%)
> 
> Is it possible for Eyal to sell 30%?
> Answer: No, as it not possible to get a 10% share out of IPO to Eyal.
> Eyal has to sell all 40%.

Agreed.

> B) 10% shares in Pool
> 
> Eyal: 40% (20%P + 20%)
> Marco: 20% (20%)
> 
> Pool: 40% (4 10%)
> 
> Is it possible for Eyal to sell 30%?
> Answer: Likely yes? Is it possible for Eyal to swap the received 20%
> share from Marco with a 10% of the Pool?

In most games (and I think this includes 1835), Eyal is prevented from
selling 30% because this would cause 70% to be in the bank pool.

But let's change the example by having the pool hold two 10%
certificates and a third player hold the other two.  Then Eyal may sell
30% by placing both his certificates in the bank pool and taking a 10%
certificate from the bank pool.  Marco must then trade his 20%
certificate for the president's certificate.

Eyal may also sell 10%.  In this case he just places his 20%
non-president certificate in the bank pool and takes a 10% certificate.

-end-