To our many readers: Thank you for your concern and well-wishing towards our redaction staff. There might have crept an undertone of panic in our article on the memoirs of Prof. Moriarty. It is as if evil leaps off the pages even though the author, and any of his contemporaries, have been dead for many years. Such demons are quickly dismissed after a healthy night's sleep and a fresh look at the maps provided.
Invasions of a different kind
As it turns out, from the final map it's fairly easy to deduce the path taken. We'll demonstrate this with the first map, entitled "Invasion of Russia Solution", which happens to be a map showing Winter 1902, not the after Winter map. The trick is to look at the colors of the dots that have no army on them, as they tell us how the situation after the first Winter must have looked like.
Invasion of Russia solution, Winter 1902
But let's start with a part of the map that did not change, namely Turkey. All Turkish home centers are still yellow, yet no unit survived and no other center was conquered by them. Instead there are two Russian units there getting removed because of a lack of centers. They are the sweepers. The principle is fairly straightforward. Put the Russian fleet in the Black Sea, move Moscow to Sevastopol and a Turkish unit to Armenia. Like a broomstick, the Russian team combines to sweep Armenia, then Ankara and then Armenia again, dislodging all three Turkish units in the process without conquering a single center.
Turkey, Spring 1902
Meanwhile the Russian home centers get overrun by the two Austrian armies. This requires sending Vienna to Warsaw and Budapest to Sevastopol, and then on to St. Petersburg and Moscow respectively. Note how Sevastopol to Moscow requires only one move, implying that that army may support the other army moving through Livonia to dislodge a unit in St. Petersburg, such as the one that took Norway in the first year. Since Norway is colored blue, this could only be one of the English units, either one of the fleets or the army if convoyed.
To know which one, it's sufficient to discover the second blue dot, the German home center of Kiel. This can *only* be accomplished in the first year by convoying the English army through the North Sea and the Heligoland Bight with the help of the German fleet.
Germany, Fall 1901
With this hint we can immediately establish the movements of all English units and fleet Kiel during the first year. While Kiel moves into the Bight and London into the North Sea to set up the convoy, Edinburgh sails through the Norwegian Sea to Norway, and then on to St. Petersburg to meet its end at the hands of the Austrians.
Russia, Fall 1902
Meanwhile the English army moves on to capture Berlin, reducing Germany to a single center, Holland. We can furthermore deduce that Germany already took Holland in 1901, as they lose Munich the same year and would otherwise have only one center left, while there are still two armies left on the map provided. The other neutral in the area, Belgium, is French and thus cannot have been the fourth center.
France is an example par excellence of solving the puzzle by finding the centers conquered. All of Belgium, Munich and Venice are his and empty. For that to happen Marseilles must move to Venice in the first year, Paris to Munich and Brest to Belgium. There the fleet gets swept by the two German armies in Ruhr and Holland, who on the return sweep brush away the remaining English fleet in North Sea, who simply needs to dock in Holland in Spring.
Lowlands, Fall 1902
What remains is to find out how the Italian units disappeared, as well as the Austrian fleet. By moving Venice out of the way the Austrian fleet can move in there, and get dislodged by the French army from Marseilles with support from one of the Italian armies. At the same time this reduces Italy to two centers and thus the loss of one unit. The obvious choice is the fleet in Naples.
Italy, Fall 1901
But how do the armies get removed? If Venice is in Tyrolia at the start of 1902, the two French armies can combine to dislodge it. The better choice is to move Munich to Tyrolia, as it can then support Venice to Trieste, which is the end situation.
Italy, Spring 1902
The problem is this: How can we ensure that the second Italian army, starting in Rome, is in Trieste at the start of Fall 1902? Given that Venice is continuously occupied, first by the Austrian fleet, then by the French army, Rome cannot use the shortest route through Venice. Think about this for a moment.
The solution is twofold. Naples could sail to the Ionian Sea and convoy the army to Albania, which is not a supply center and thus does not increase the SC tally for Italy, followed by Albania to Trieste. Or we could choose to remove army Rome instead of fleet Naples during the first Winter. In that case the fleet may sail through the Ionian and Adriatic to Trieste to get dislodged there in Fall 1902. This is the more economical solution, but at this point in the story no such constraint existed yet, so it's more a question of personal preference.
Italian Army Albania Variation, Fall 1901
The other two solutions, the Invasion of England [click to get pop-up of final map] and the Invasion of Austria [click to get pop-up of final map], are left as an exercise for the reader.
The colors of the dots
By sending the Italian fleet in Naples to Smyrna to be dislodged there, the need to reduce Italy to two centers in the first year disappears. Italy may even capture centers, for example by moving its two armies to Venice and Tyrolia, thereby surrounding the Austrian fleet in Trieste, followed by Tyrolia supporting Venice to Trieste. This is nearly the same situation as in Holmes' solution, but now with Italy, not Austria, owning both Trieste and Venice.
Venice and Trieste Italian Variation, Fall 1901
To make Venice and Trieste both change hands, a little dance is in order. First we move Venice to Piedmont (not Tyrolia), Rome to Venice and Trieste to the Adriatic Sea. In the Fall, army Venice moves to Trieste and the Austrian fleet in the Adriatic sails in from behind to capture Venice. In Spring, the army in Piedmont supports Trieste back to Venice to dislodge the fleet there after which the two armies can move to their end positions in Tyrolia and Marseilles.
Venice and Trieste Swapped Variation, Fall 1901
To trade Paris with Marseilles without capturing Marseilles in the first year (as that would bring the French down to one center), it's necessary to send Venice over Munich to Paris, and Vienna straight to Marseilles. Note that Vienna has to hold in the first season to let Venice pass through Tyrolia, but luckily Marseilles is only three moves away, so that is not a problem.
Munich Italian Variation, Spring 1901
How do we get rid of the Austrian fleet without support from the army starting in Venice? Clearly the Austrian army Vienna is of no use here. It is the same color as the fleet and thus cannot support to dislodge.
The solution is to invoke the assistance of one of the about to be eliminated powers. This assistance cannot come from the German army in Munich, because it, too, is not allowed to go to Tyrolia during the first season. The French army in Marseilles however has no such obstructions. Let it move to Piedmont, while Trieste goes to Venice and Rome holds. In Fall Piedmont supports Rome to Venice, while Vienna moves up to Tyrolia. In Winter, the French army gets disbanded, after which all remaining units simply have to proceed to their destinations. This is both a nice demonstration of the use of a sacrificial unit and an example of an end situation where neither Venice nor Trieste change owners.
Paris and Marseilles Swapped Variation, Fall 1901
From this we learn that a simple change in the way one fleet gets eliminated can truly cause a multitude of different end situations with respect to center ownership. Puzzle makers, beware.
Inside Moriarty's mind
Moriarty left several indications of how he had originally solved the puzzle. Let's see how close we come to deducing his solution.
First we are told that he uses both surviving French units in 1902 to eliminate an English army and fleet. Assuming that 1901 was played out in a similar manner as in Holmes' solution, there's an English fleet in Belgium, an army in Brest, a French fleet in the English Channel and a French army in Piedmont or Burgundy at the start of 1902.
French Army Burgundy Variation, Winter 1901
The end position should be such that only the two French units remain and are located on non-SC territories. As the two English units both captured a supply center, that means that the unit attacking the first time should also attack the second time, otherwise it would be stranded on an SC. As such the supporting unit will stay in place throughout the two seasons, and thus has to be on a non-SC territory to start with.
The English unit surviving the first season should move to a non-SC territory adjacent to the other unit and accessible to both French units. The only candidate is Piedmont, as it's the only coast between Belgium and Brest, accessible both to the army and the fleet. As a consequence attacking with the French fleet is out of the question. We can't put the French army in Piedmont, because it would block the remaining English unit moving in. Neither can it be in Burgundy, because it would block the Austrian army on its way to Paris.
Attack with the army however can happen in a number of ways. First dislodging fleet Belgium, then the army in Piedmont; or first army Brest, then the fleet in Piedmont, both are possible.
French Army Burgundy Variation, Spring 1902
The army can also start in a number of other places other than Burgundy or Piedmont, such as Ruhr, Paris or Gascony. The most economical of these is to start in Paris, as it would allow the army to simply hold throughout 1901. Whether Moriarty chose to do so, we can only assume. Only the situation at the end of the Fall season can be determined with certainty.
French Army Paris Variation, Spring 1902
Perhaps we better predict the path taken up North. There, we are told that the Russian army in Norway moving through Sweden is convoyed through Barents Sea to Kiel. If that is the case then it is the other Russian army in Berlin that had to move on to Holland. Without assistance from the first army, however (moving in from behind), it requires the support of a foreign unit to dislodge the English fleet in Holland. Neither the German fleet, executing the convoy to Kiel, nor any of the French units, occupied with eliminating the other English units, can be of assistance.
Russian Army Sweden Variation, Spring 1902
The only way out is to have a German army survive the first year. As in the "Invasion of Russia Solution", this can be done by capturing Holland, as we know that Belgium gets taken by an English fleet. As the army in Berlin is still needed to dislodge the Russian fleet in Livonia, it will be the army in Munich that gets assigned to this task. After it moves to Holland in 1901, it has to move out again to make space for the English fleet coming in from the North Sea. To make sure that it will be disbanded in Winter, it can only move to Ruhr and not Belgium. From there it supports the Russian army in Kiel, coming from Berlin, to its final destination Holland.
German Army Ruhr Variation, Fall 1902
Did we now trace the full path of every unit involved? Not exactly. We can't tell whether army Munich moved through Ruhr or Kiel to reach Holland in 1901. Nor can we tell whether it was the English fleet in London that went to Belgium or the fleet from Edinburgh. Such details, trivial as they are, can only be presumed - unless your name is Holmes, so familiar with the writer that he can perfectly read his mind.
This just in… Scotland Yard has released more material related to the case, including what looks like complete game records of the different variations! We will compile these and include them here, so that you, our esteemed reader, can check out how close you got to the original solutions:
Top secret: Scotland Yard has postulated a connection between this case and the case of the Last Man Standing. In correspondence which has been confirmed to be from the hand of Baron Hervé van Rompuy-Leterme, the Baron thanks the addressee (Moriarty? Holmes?) for informing him on the solution entitled the "Invasion of Russia", and that he had taken great delight in working it out further in a form suitable "for entertaining the public at the next Congress". The Yard presumes that he has reworked the Russian solution into the Last Man Standing problem which we have presented in our Spring 2012 Movement number. A golden hint for our devoted readership to go back and solve the case.
Tributes: The original solution is from the hand of Manus Hand, assisted by John Woolley. The first one to send him a solution (rendered here as the Invasion of Russia solution) was Mario Huys, author of the solution articles. The second person was Matt Stewart, who came up with the Invasion of England solution. All other variations were worked out by Mario with inspiration from Manus.
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