Supply Paths

[Shannon V. OKeets]

In rewriting the supply paths rules, I came across a possibility that is not real far-fetched, but I want to see if you agree with my understanding.

In the screen shot below, I believe that Rundstedt is in supply by tracing 3 Basic Supply Path hexes to Cernauti, a free Rail Supply Path hex to the mountain unit and the 4th Basic Supply Path hex due west to a rail line which then traces back to Germany. This, in turn puts all the German units in supply, because they trace to Rundstedt.

The tricky bit is that the HQ is tracing secondary supply so it can use the hexes connected by rail lines for free, even though it is using 2 discontiguous rail line segments.

Do you agree?

[lomyrin]

Yes, I agree that th HQ is in supply.  The HQ is a seconday supply source and it traces a railway supply path to a primary supply source. The 4 non rail hexes allowed in a railway supply path can occur anywhere along the path.
 
Lars

[ptey]

Agree, all the German units except the "9-4, 1 Infantry Corps" are in supply (but in fine weather only).

[Shannon V. OKeets]

Thanks.

I've decided I will just do the fundamental supply calculations at the present. I had thought about building into them information about vulnerablilites so the AIO could know where to attack and defend supply lines, but that increases the complexity of the routine quite a bit. I'll come back to it later and make it a 'layered' routine that uses the fundamental supply calculation routine.

What I have decided to change in the design is to record all the primary supply sources for every major power and those minor counties that are at war. To those lists I will add potential secondary supply sources, and mark each secondary as being a valid or invalid supply source depending on whether it can trace a path back to a primary. The search for supply then can be done from each unit towards a known supply sources rather than a spiralling exhaustive search as is done in CWIF.

Finally I will store the last valid supply path for each unit, to expedite the calculations each time it needs to be done. What I mean by that, is the routine will first try the previous supply path and see if it is still valid. This is also a good thing to do for units that were out of supply last time they were checked, to see if the old/last successful path has been reopened (e.g., if the weather has gotten better and the basic supply path has changed from 3 back to 4). The longer search for a valid supply path will therefore only be performed once, when the unit arrives on the map, and whenever it's previous supply path becomes disfunctional. The overall objective, obviously, is to minimize calculation time for determining supply.

[mldtchdog]

Only if Hungary is allied. otherwise the russian zoc's block the rail lines
 
2.4.2 Tracing supply
You can't trace any supply path: into a hex controlled by a neutral country

[Mziln]

Mldtchdog has correctly pointed out “only if the Axis has aligned or conquered Hungary”.  Then you could trace supply to Budapest (a secondary supply source).

2.4.2 Tracing supply

A secondary supply source for a unit is:
• an HQ the unit co-operates with (see 18.1); or
• the capital city of a minor country controlled by the unit’s major power; or
• the capital city of a major power, or a minor country, conquered by the unit’s major power, or by a major power the unit co-operates with.

Example: Poland’s controlling major power is the Commonwealth. Warsaw is a secondary supply source for Commonwealth units, in addition to being a primary source for Polish units.

A city can only be a supply source for a unit if it has not been controlled by the other side at any time in the turn.

A supply source can supply any number of units.

Assuming that the weather isn't hampering supply.

[Incy]

You can't trace to Budapest, since it's a secondary source. A railroad path must be to a primary source, which Budapest is not.

[Froonp]

ORIGINAL: Shannon V. OKeets

In rewriting the supply paths rules, I came across a possibility that is not real far-fetched, but I want to see if you agree with my understanding.

In the screen shot below, I believe that Rundstedt is in supply by tracing 3 Basic Supply Path hexes to Cernauti, a free Rail Supply Path hex to the mountain unit and the 4th Basic Supply Path hex due west to a rail line which then traces back to Germany. This, in turn puts all the German units in supply, because they trace to Rundstedt.

The tricky bit is that the HQ is tracing secondary supply so it can use the hexes connected by rail lines for free, even though it is using 2 discontiguous rail line segments.

Do you agree?

A bit late (lot of work these days), but I agree too [:D].

[Mziln]

ORIGINAL: Incy

You can't trace to Budapest, since it's a secondary source. A railroad path must be to a primary source, which Budapest is not.

Since I did mention it was a secondary source. I assumed that you would understamd that you would trace from Budapest to a primary supply source or another secondary supply source.

2.4.2 Tracing supply

A secondary supply source of the tracing unit must be able to trace a supply path either to a primary supply source or via another secondary supply source. That other secondary source must also be able to trace a supply path either to a primary source or via another secondary source, and so on. There can be any number of secondary supply sources in this chain but it must end up at a primary supply source of the unit tracing the path.

Budapest would therefore be able to trace a new 4 hex supply path or use the rails to a primary supply source or another secondary supply source.

Supply paths

You trace a supply path from a unit to a primary supply source. If you are tracing a path from a secondary supply source to a primary supply source, it is a railway supply path.

If you are tracing any other supply path, it is a basic supply path.

A supply path, basic or railway, can be up to 4 hexes. Each Asian or Pacific (AfA/AiF/AsA Option 1: or African, American or Scandinavian) map hex you trace into counts as 2 hexes. Each off-map hex counts as 4 hexes, so you can only trace a basic supply path into an adjacent hex during clear weather.

Each desert, or desert mountain, hex your supply path enters counts as 1 extra hex (i.e. counts as 2 on the European maps, 3 on the Asian and Pacific maps and 5 in off-map hexes).

This maximum distance will vary in some weather (see 8.2.2). In those cases, you determine the length allowed for each path by the weather in the hex occupied by the unit or secondary source you are tracing from.

Please ignore any references to any map other than European.

[lomyrin]

As Incy pointed out above the HQ cannot trace a railway supply path to Budapest even when Hungary is aligned to or conquered by Germany since Budapest is only a seconday supply source and would require the HQ to trace a 4 hex path with no railway benefit.
 
The HQ can trace a railway supply path to a German primary source provided that Hungary is aligned to, or conquered by, Germany.
 
Lars  

[michaelbaldur]

a HQ can trace a railroad supply path to a second - a primary or another HQ ...... any number of second or HQ can be traced to .... the path just have to end at a primary .... but can you make a railroad path to a primær you can all must always trace to a primær...

[michaelbaldur]

a railroad path to a second. you can all must always trace to a primær...

[Mziln]

All my quotes are from the RaW (and Patrice has not corrected me yet [:D]).

Railway supply paths

A hex a railway supply path enters, by moving along a railway or road, does not count against the 4 hex limit. A hex it enters across a straits hexside also does not count against the limit, so long as the hexes on either side of the straits are railway hexes.

The 4 non-rail hexes can occur anywhere along the path. Although you will mostly use them to trace supply from an HQ to the railhead, they can be handy for re-routing around an enemy unit that’s blocking a vital rail link.

This way you can chain from:

One HQ (a secondary source) 4 hexes a rail.

To another HQ (a secondary source) 4 hexes to another rail.

To a aligned/conquered capital city of a minor country (a secondary source) 4 hexes to another rail.

Etc. to a primary source.

See my post #9 quote 2.4.2 Tracing supply.

[Froonp]

ORIGINAL: Mziln

All my quotes are from the RaW (and Patrice has not corrected me yet [:D]).

Railway supply paths

A hex a railway supply path enters, by moving along a railway or road, does not count against the 4 hex limit. A hex it enters across a straits hexside also does not count against the limit, so long as the hexes on either side of the straits are railway hexes.

The 4 non-rail hexes can occur anywhere along the path. Although you will mostly use them to trace supply from an HQ to the railhead, they can be handy for re-routing around an enemy unit that’s blocking a vital rail link.

This way you can chain from:

One HQ (a secondary source) 4 hexes a rail.

To another HQ (a secondary source) 4 hexes to another rail.

To a aligned/conquered capital city of a minor country (a secondary source) 4 hexes to another rail.

Etc. to a primary source.

See my post #9 quote 2.4.2 Tracing supply.

No, because a railway supply path can only be used from a Secondary to a Primary supply source.

************************************
2.4.2 Tracing supply
(...)
Supply paths
(...)
If you are tracing a path from a secondary supply source to a primary supply source, it is a railway supply path.
If you are tracing any other supply path, it is a basic supply path.
************************************

From a secondaty to another secondary, you trace a BASIC supply path (4 hex limit).

But the Railway Supply path can also contain 4 non rail hexes :
************************************
2.4.2 Tracing supply
(...)
Supply paths
(...)
A supply path, basic or railway, can be up to 4 hexes.
(...)
Railway supply paths
A hex a railway supply path enters, by moving along a railway or road, does not count against the 4 hex limit.
************************************

Thus, I would correct what Steven wrote in mail #1 of this thread :
Instead of

In the screen shot below, I believe that Rundstedt is in supply by tracing 3 Basic Supply Path hexes to Cernauti, a free Rail Supply Path hex to the mountain unit and the 4th Basic Supply Path hex due west to a rail line which then traces back to Germany. This, in turn puts all the German units in supply, because they trace to Rundstedt.

I would say :
In the screen shot below, I believe that Rundstedt is in supply by tracing 3 Railway Supply Path hexes to Cernauti, a free Rail Supply Path hex to the mountain unit and the 4th Railway Supply Path hex due west to a rail line which then traces back to Germany. This, in turn puts all the German units in supply, because they trace to Rundstedt.

I mean that, Rundstedt only trace ONE TYPE of supply path here, because he traces back to a Primary supply source in Germany, so it is a Railway supply path that contains 4 non railway hexes.

[Shannon V. OKeets]

Here is an abstract of what I see as the different supply paths that are possible. I will use this diagram (or something similar) in the tutorials and also include screen shots of board positions to demonstrate what these abstractions will look like during a game. This is important for me now, because I am working on redesigning/recoding the supply routines. I want to be absolutely certain that I have these rules perfectly correct, before I start writing actual code.

From top to bottom, we have a unit:
1 - within range of a primary supply source.
2 - within range of a secondary supply source which is within range of a primary; this is a rail supply path, even though no rail lines are used.
3 - same as #2 but with a rail line used.
4 - same as #3 but with two discontiguous rail lines used; there are still only 4 hexes permitted that are hexes not connected by rail lines; this was why I posed the original question in this thread.
5 - same as #3 but with linked secondary supply sources; this was Patrice's point that secondary supply sources are connected by basic supply paths.
6 - within range of a secondary supply source that can reach an Oversea Supply Path and then a Rail Supply Path; the Overseas Link reduces the non-connected rail hexes in the Rail Supply Path by 1; Only 1 Overseas Supply Path segment is permitted in a supply path.
7 - same as #6 but showing that a rail line can be used both before and after the Overseas Supply Path.

There is another possibility not shown where the Secondary (e.g., an HQ) is in a coastal hex and connects directly to the Overseas Supply Path without going through a port.

[Froonp]

This schema seems good to me.

[Froonp]

But you should write on your schema that the black lines are the part of the railway supply lines that are not on a railway. This would be clearer.
Also, you should add some note, maybe, beside the "contiguous sea areas" note, to say that those there are conditions for that sea areas to be usable.

[npilgaard]

ORIGINAL: Shannon V. OKeets
6 - within range of a secondary supply source that can reach an Oversea Supply Path and then a Rail Supply Path; the Overseas Link reduces the non-connected rail hexes in the Rail Supply Path by 1; Only 1 Overseas Supply Path segment is permitted in a supply path.
7 - same as #6 but showing that a rail line can be used both before and after the Overseas Supply Path.

There is another possibility not shown where the Secondary (e.g., an HQ) is in a coastal hex and connects directly to the Overseas Supply Path without going through a port.

Also, a unit in a coastal hex can use an Oversea Supply Path directly; and a unit inland can get acces to an Oversea Supply Path via a port. In both cases the supply are non-Rail Supply Paths, if the don't go through a secondary supply source.

[Mziln]

[:D] Thanks Patrice [:D]

I know we discussed this before in the forums but I could not remember where. I wish you had jumped in sooner.


The RaC (Rules as Coded) need to reflect that you are either tracing supply from:

A unit or secondary source to a secondary source where you cannot use the rail/road network; OR

A unit or secondary source to a primary source where you can use the rail/road network.

[Shannon V. OKeets]

ORIGINAL: npilgaard

ORIGINAL: Shannon V. OKeets
6 - within range of a secondary supply source that can reach an Oversea Supply Path and then a Rail Supply Path; the Overseas Link reduces the non-connected rail hexes in the Rail Supply Path by 1; Only 1 Overseas Supply Path segment is permitted in a supply path.
7 - same as #6 but showing that a rail line can be used both before and after the Overseas Supply Path.

There is another possibility not shown where the Secondary (e.g., an HQ) is in a coastal hex and connects directly to the Overseas Supply Path without going through a port.

Also, a unit in a coastal hex can use an Oversea Supply Path directly; and a unit inland can get acces to an Oversea Supply Path via a port. In both cases the supply are non-Rail Supply Paths, if the don't go through a secondary supply source.

Thanks. I had missed those. A CW unit in Portugal tracing to London comes to mind as an example.