Sherlock Holmes,
Consulting Diplomat

by Mario Huys,
Master Ænigmatist

Solution to the Suwati Portage Conundrum

I took out the old game board and put the pieces in their starting position, trying hard to remember the opening that would lead to seven dislodgments in the first Fall season. Holmes must have noticed my hesitation, because he suddenly produced a file from his cabinet and nonchalantly tossed it at me, saying: "Here, this might help."

Inside I found a complete copy of my story on "The Case of the False Start". Surprised I could not resist to ask if he kept a copy of every one of my articles detailing his exploits, but he denied it. "That would be quite absurd. I can perfectly recall anyone of my cases, but having all these stories in print would inevitably alter my own recollection of the facts. It's my brother Mycroft who gave it to me when he heard that another Suwati mystery had arrived, even without knowing any of the details."

Holmes had always sustained that his brother had even a sharper mind than his, but lacked the energy to make it a profession, so I was less surprised than I ought to be upon such a remarkable exploit. As I turned the pages I reconsidered any of the assumptions I had made, just like they would do. I quickly realized that some would need to be reexamined in view of the Portage Convoy rule.

"Here are the diagrams showing the seven dislodgements in the first year," said I. "I'll start by following these. Seven dislodgements and at least one retreat, from the Channel to London. Can this be improved with the aid of the Portage Convoy rule?

"No dislodgement in Spring, that remains the case. Neither can the English army be put in play in such a way that another unit may be released from duty. It can however be used to convoy Edinburgh to Wales. If London opens to the North Sea, we obtain the same situation for the Fall, with the two fleets reversed and a first convoy on our watch."

"You are scintillating today, Watson. It's extremely important to notice that all units except the English army must be involved in a dislodgement in the Fall turn. As a consequence no convoys will occur in that season. Keep onto it."

I had no need for the encouragement, as I felt something of the same joy that my friend must experience when he sets himself to solve one of these challenges.

"Let me see if there could be some more portage convoys in Spring. Not the French fleet, as it must move out to the Channel. There's no use in convoying the Turkish fleet to any of the Turkish provinces. Nor to Bulgaria, as it can only attack Rumania from there, or get dislodged, both resulting in the capture of a neutral center. What about a convoy to the Aegean Sea? From there it could attack the Italian fleet in Ionian with support from the Austrian fleet."

"No, it won't. Remember that portage convoys can only be done from and to coastal provinces."

"Right, you see that I'm still getting used to the concept. Well then, that only leaves the Black Sea as a valid destination. Which means Russia must move to Armenia to give the two Turkish armies a target. The Northern fleet however might already be convoyed to Sevastopol."

"In that case I would worry about your convoyer."

"Army Moscow? True, Moscow is three spaces away from any foreign unit, so cannot be involved in a Fall turn dislodgement unless the army moves out. Let's have it move to Sevastopol as before, and the Northern fleet to Livonia. For the German fleet we only need to consider a convoy to Prussia. There it can be attacked by army Warsaw and the fleet in Livonia. But how can Berlin get involved? Only Warsaw may move to Silesia, but that would preclude an attack on the German fleet. Germany must therefore move as before, fleet to Baltic and army to Prussia. How am I doing?"

"Pretty well. But the trickiest part is still to come."

"You mean the Italian and Austrian fleets. There is quite an opportunity there. But again, it's the immovable convoyer that limits the options. Fleet Naples can only be convoyed by army Rome. And that army can only be put to use in Fall if the Austrian fleet in Trieste is brought near. Therefore for both fleets to be convoyed at the same time there is only one option: a convoy of Naples to Tuscany via Rome and of Trieste to Apulia via Venice!"

"Quite so. And yet, that would not do. I could let you go off this false track for hours, but our guests would be here first. So, let me help you out here. Only the Austrian fleet must be convoyed, and it must be convoyed to Rome."

Frowning deeply, I said: "But that's one less convoy. Besides, you could as well convoy the fleet to Naples, as that increases the convoy length while still allowing for seven dislodgements."

But Holmes readily dismissed my objections. "It will be amply compensated by the higher number of retreats. Remember that retreats take precedence over convoys."

"Right, retreats, I was going to come to that. For the sake of the argument I will move Rome to Tuscany and let the fleet in Naples hold."

Portage, Spring 1901 Movement
The Suwati Portage Conundrum S1901M
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With the Spring moves laid down, I cautioned myself against exaggerated optimism for the Fall. Even though the task seemed light, I was moving in unknown territory, towards the point furthest away from both the starting position and the, safe for the identity of the units, identical end position.

Take England. The first impulse would be to move Wales to the Channel. But since the fleet in the Channel would eventually be dislodged and disbanded, it would be the same fleet that started in London that would end up there. Instead I let Wales support the North Sea to the Channel, making Holmes nod appreciatively. As expected, I let the French fleet retreat to London.

Going in the same order as in Spring, I next considered the Black Sea area. There could be no doubt about using the Austrian army in Rumania to dislodge the Russian army in Sevastopol with support from the Turkish Black Sea fleet, as an attack on Rumania would result in the capture of a neutral center. The Russian army could now retreat to Moscow, Ukraine, or off the board. I left it on the Moscow-Ukraine border for now and moved on to Armenia.

In Armenia, choosing which Turkish army to dislodge and thereby destroy the Russian fleet was harder to predict, if it mattered at all. Unless… "Holmes, what if Constantinople had opened to Smyrna and Smyrna to Syria? That would give the Russian fleet a chance to retreat to Ankara, resulting in the Winter disband of the Turkish fleet. The two armies could then combine again to remove the fleet in Spring before switching home centers."

"And leave Ankara in Russian hands?…" my friend said incredulously.

"Point taken. Apparently even the Portage Convoy rule does not condone the indiscriminate capture of home centers. Without a second fleet the loss of a fleet's home port cannot be remedied in the short span of two game years available to us. I will try to keep that in mind."

The Russian fleet, without a space to retreat to, would have to be taken off the board. I decided to attack with Ankara and support with Smyrna so that both armies would be only one move away from one another's home centers, their likely final destination. I tossed the fleet in the box and turned to the North.

Given the imminent loss of Munich, it would be best to keep Prussia close at hand, so it was the Baltic Sea fleet that attacked Livonia. The Russian fleet there could only retreat to its own port or disband. But since there had to be a fleet left to recapture Sevastopol the next year, and since retreats were preferred over disbands and rebuilds, I let the fleet retreat to St. Petersburg. At the same time this fleet would have to be convoyed through Moscow, so I pulled the army retreating from Sevastopol back to its starting point. Munich was equally self-evident. Attacking with the French army left the Russian army in Silesia, where it could be dislodged by the German armies provided that the army in Munich would retreat to Berlin.

I looked up at Holmes expecting a word of praise, but his reaction was exactly the opposite. "That's quite a train wreck you set up," he said mockingly. "Consider the fate of the Turkish fleet. It already has no good place left to go to."

I stared at the fleet reigning supreme over the Black Sea watershed. It could not be disbanded in Winter, as no Turkish centers were captured. There were no fleets around to dislodge it in the Spring, and no centers would be gained or lost by Turkey during 1902. The only approach left was to dislodge and disband it in the Fall after landing on a coastal region in Spring. Rumania with its supply center was out of the question for the attack would be in Fall. Armenia was not a candidate either, as no more than one enemy unit, in Sevastopol, could be brought near, and convoying through the Black Sea was not possible when that fleet was moving out. That only left one option.

"Black Sea must move on Sevastopol," I said ponderously. "That's unfortunate, as I thought of convoying the Russian fleet there in Spring. And if the convoy is in Fall… There will be no supporting unit to facilitate the dislodgement of the Turkish fleet. A conundrum…

"Turkey must go to Sevastopol in Spring, dislodging the Austrian army there. This army, too far from home, has to disband. Russia must use Moscow in Fall to support the recapture of his home center with his remaining fleet. That fleet therefore has to be convoyed in Spring. If not to Sevastopol, then to a neighboring coastal province. Not Armenia, as Sevastopol is under attack and cannot therefore take part in a portage convoy. Rumania then, through Moscow and the Ukraine?…

"Wait, the dislodged Russian army in Fall 1901 could retreat to the Ukraine instead of Moscow. If Russia were able to build an army in Moscow, the convoy route would be a fact. That requires the capture of a center… Munich!" I cried.

Triumphantly I pushed the French army back to Burgundy replacing it with the Russian army from Silesia, then pulled the other Russian army to the Ukraine and through a quick count confirmed that Russia was now eligible for a build in the now vacant Moscow.

"You surpass yourself, Watson," Holmes said with a smile. "You prove that you *can* follow a clue through to its inexorable conclusion."

"I hope I will continue to prove myself a worthy student of your methods," I said in all sincerity. "The road is still long."

Nothing comes closer to the truth, I thought, as I eyed the Austro-French-Italian tangle. Even the composition of the two triples was in doubt, I realized now, as the Italian armies could choose to go either way. And if Venice participated in the Northern triple, any of these armies could be attacker, supporter or victim. But I had one thing to hold on to: my friend's assurance that there would be an ample amount of retreats.

I set out, as Holmes would do, from the little that was known. In the Southern triple the Austrian fleet in Rome would be the victim, and the Italian fleet part of the attack. From Rome there were three places to retreat to for a fleet. Naples however, like Ankara, could not be taken, as there would be no way for Italy to put a new fleet in there at the end of the second year. The Tyrrhenian Sea was a possibility, but it would present the same problems as the Black Sea, severely limiting the attack options for the second year. I therefore concentrated on Tuscany, where a fleet would be able to participate in an attack, either as aggressor or victim, or even be convoyed.

For a retreat to Tuscany to be possible, the army there had to move out. This could be accomplished by letting it attack the French army in Piedmont with the aid of the Austrian army in Tyrolia. The French army in turn could retreat to Marseilles or, if the other Italian moved out, to Venice. Losing a home center would allow for the disband of the Italian fleet, which was otherwise not in a great position to contribute to the events in the second year. Not only that, with the Italian army trading Venice for Rome and a foreign army in Venice, the scene was set for another great slaughter in the city of the Doges.

With so many advantages I hesitated no longer, pulling Venice to Rome and Tuscany to Piedmont, lightly tapping the supporting units, and retreating Rome to Tuscany and Piedmont to Venice.

"Good Harry," my friend cried. "Soon there will be no more need for my services. Your next bundle may well be called 'The Adventures of Dr. John Watson', if I'm not very much mistaken."

"They would probably not fetch a penny. I take it then that you approve of my approach?"

"You are spot on. The same effect may also be had by simply rotating the engaged units clockwise, but the requirements of the puzzle entice a more violent progression."

Portage, Fall 1901 Movement
The Suwati Portage Conundrum F1901M
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In excellent spirits I proceeded to execute the Winter adjustments. England, Germany and Italy had all lost a center, and hence I removed the English army, the German fleet and the Italian fleet. Turkey and Russia had stayed equal, but Russia had lost a fleet - remarkably the only unit disbanded in the previous season - so was entitled to a build, which was naturally army Moscow. Austria had gained a center, so I built a fleet in Trieste, although other choices were possible. And France even had two builds. One was a fleet in Brest in accordance with the Channel plan. For the other I decided on an army in Marseilles to increase the concentration of units in and around the Italian boot even more.

I took the army out of the box, but didn't yet put it down. Something held me back. Was it Holmes' jovial mood, so reminiscent of the man who had challenged the Sultan with his own riddle? I remembered however that his triumph had not been complete. For some reason his inventive solution had not been superior to the Sultan's, merely equal. Why?

I took up the copy and reread the last few paragraphs. Then it dawned on me. The condition for allowing the French fleet to remain in the Channel after the 1902 Fall turn, was that all French home centers had to be occupied by an adequate set of units. This was also the reason why Holmes' alternative had no more dislodgements than the Sultan's. That meant that there had to be an army in Paris and in Marseilles. The army in Burgundy could move to Marseilles, but not to Paris, as that's where it came from. Building in Marseilles only to move it to Paris was pointless. The second build therefore had to be an army in Paris.

I noticed that my friend had raised up from his chair and was taking care of his plants. I took that as a sign to tinker further on my own.

Watson's Winter 1901 Adjustment
The Suwati Portage Conundrum, Watson's W1901A
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The board was set for 1902. Care had to be taken to have the whole starting position reconstructed at the end. I started by dislodging London from Wales with support from the Channel, retreating the French fleet to the North Sea. St. Petersburg was portage convoyed to Rumania over Moscow and the Ukraine, while Turkey supported his own fleet into Sevastopol, destroying the Austrian army there. Two more dislodgements could be had in Italy and one more in Germany. I let the Italian army in Piedmont dislodge the Austrian fleet in Tuscany, aided by his Roman compatriot, and the Austrian army in Tyrolia dislodge the French army in Venice, supported by the freshly built Austrian fleet. That way the stage was set for another dislodgement in Venice in the Fall.

Munich posed a problem. Since Burgundy had to end the year in Marseilles, it could not move to Munich. All it could do was to support Berlin in there in order to dislodge the Russian army. But if Berlin moved, it would have to move back a turn later, and Prussia's role would be constricted to moving through Silesia to Munich, without a chance for a dislodgement on its own. A Russian retreat would not alter that, even if the German army had not come from Berlin. It might retreat to Tyrolia, with the French army from Venice retreating to Piedmont, but the only available unit to assist in another dislodgement would be the Austrian fleet in Trieste, so that was no good. Come what may, only one dislodgement could occur, so the army in Berlin could as well hold and help the second German dislodge Munich in Fall.

Watson's Spring 1902 Movement
The Suwati Portage Conundrum, Watson's S1902M
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Watson's Fall 1902 Movement
The Suwati Portage Conundrum, Watson's F1902M
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Watson's Winter 1902 Adjustment
The Suwati Portage Conundrum, Watson's W1902A
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I had now a first solution, as the Fall turn had already been entirely determined. I was curious how well I had scored. 15 dislodgements, the same as before. 7 retreats. And 3 convoys, one involving two convoyers, for a total convoy length of 4. That was disappointing, for Sherlock had told me that the number of retreats and convoy length together would equal the total number of dislodgements. Worse, I could still not tell where the Sultan had hidden himself, for no unit had been convoyed more than once.

Apart from the convoy to Sevastopol, there had been two convoys in Spring 1901 and none in Fall 1901. It was highly unlikely that there would be one in Fall 1902, as all surviving units had to end on one of their own home centers, except for the French units in excess of those occupying the home centers. That meant in theory that Venice was available after it had retreated to convoy one or the other Austrian fleet home. But the one in Tuscany would need to be destroyed, while the other one had not yet been convoyed, being freshly built. And convoying it twice in a row was a very tall order. It would therefore have to happen in Spring 1902, with one of the fleets from the first season. With no armies around, the English fleet could be disregarded. It had to be the Austrian fleet in Tuscany.

Satisfied so far I considered its options, and to my dismay discovered there were plenty. The fleet could be convoyed all the way to Livonia or Brest. Although it would significantly increase the total convoy distance, it would also irrevocably diminish the number of dislodgements, and those had to take precedence. A short convoy was therefore more opportune, and Venice was the primary candidate. Especially since the Austrian army in Tyrolia could be diverted to Munich to keep the number of dislodgements equal. The convoy could either happen through Rome or Piedmont, with the other Italian unit supporting the attack on the French army. That meant the Austrian fleet in Trieste had nothing to do. It could just as well be replaced with an army in Vienna. If Venice retreated to Tyrolia and Munich, displaced by Tyrolia, to Bohemia, the scene was set for an extra dislodgement in the form of Tyrolia to Bohemia with support from Vienna. Just like the Channel fleet the surviving French army could then be disbanded because of a loss of centers.

I felt I was getting extremely close. In one swoop fell I had added one convoy, two retreats and one dislodgement. That brought my total to 16 dislodgements, which was an improvement over the first solution, and 14 retreats and convoys. Only two more. Where could they hide? Or had Holmes miscalculated? Or worse, had he missed the 16th dislodgement? The thought thrilled me, even as it sounded ludicrous, and worse, would certainly mean the loss of the Suwati port deal.

As I imagined the implications, I felt the man himself looking over my shoulder.

"Ah, I see you have discovered the benefit of a build in Vienna. And the location of the Sultan?"

"Venice. Let me demonstrate," I said while rearranging the pieces to their Spring 1902 positions.

"There's no time for that, I'm afraid. I saw the carriage with our guests appear in our street just now." He picked up the fleet in Brest and dropped it in Marseilles. "Your missing convoy, to Brest through Burgundy and Paris, length two. No doubt you would have discovered it yourself in time, but what you will come to hear next may well require your full attention. Straighten your jacket, that must be them at the doorbell now."

Winter 1901 Adjustment
The Suwati Portage Conundrum, W1901A Solution
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Spring 1902 Movement
The Suwati Portage Conundrum, S1902M Solution
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Fall 1902 Movement
The Suwati Portage Conundrum, F1902M Solution
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Winter 1902 Adjustment
The Suwati Portage Conundrum, W1902A Solution
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-- Dr. John H. Watson
via Mario Huys

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