Ok, I've posted this strategy before, but it was about 7 years ago, and I doubt anyone goes THAT far back into the archives in search of strategy articles. Needless to say, I've re-written it entirely rather than post my old one, because I find this sort of thing enjoyable. Also, apologies for the tongue-in-cheek Holocaust reference in the title: I read a book on how to generate click-bait headlines. Buckle Up.
The Double Hedgehog
or
"How I Learned to Stop Worrying and Win Before 1908"
--
What if I were to tell you that there are a sequence of moves, which, if played by two of the powers, virtually guarantee their place in a finish? Would you believe me? Maybe you're wondering which two powers I mean. "Sea-Lion", some of you are saying. "Juggernaut", others. The obvious answers are wrong, however. We're talking today about the most overpowered alliance in the game: "The Austro-Turkish Double Hedgehog"
Austria and Turkey? Really? Yup. And the secret is simple: Safe is Strong
Some people will tell you that the safe play is not the way to win, that if you want to win you have to take some chances, or at least play aggressive. This is not true if you are Austria and Turkey, and find out early that you can be friends.
Austria:
A Bud -> Ser
F Tri -> Ven
A Vie -> Gal
Austria opens with the Southern Hedgehog of Richard Sharp fame -- reactionary, defensive, and non-committal -- guaranteeing a build. This is virtually the only opening I will play as Austria, and I personally think that the results speak for themselves. The only diplomatic requirement for Austria is that he arranges the Galician bounce with Russia beforehand. The Venice move can be a pre-arranged bounce, or a surprise -- both ways work.
Turkey:
A Con -> Bul
A Smy -> Con
F Ank -> Arm(!)
The Turkish Hedgehog, popularized by Nicholas Wyte. One of the most beautiful openings in the game of Diplomacy. The only diplomatic requirement for Turkey is that he arranged a bounce with Russia in the Black Sea -- it is imperative for this strategy to work that Russia play F Sev -> Bla -- generally not a hard thing to accomplish. "I'm going to move to the Black Sea" is generally all Turkey has to say to get it done.
Now, look at the board. Let's assume the most antagonistic move-order possible from Russia.
https://imgur.com/a/N5zEhRussia is now in a huge pickle. Sevastopol is wide open, and needs to be covered. But Rumania needs to be picked up, and there is no army in Galicia to help. It's true that Ankara stands open, but as we shall see, that's the whole point. The bounces in Galicia and Trieste-Venice has left Austria left flank well protected, and immune against any attack from Italy (even if Italy had moved to Tyrolia, the bounce in Venice will have prevented the army in Rome from bringing any more force, and both Trieste and Vienna are covered). Austria is safe.
Both Austria and Turkey can now make whatever promises they want to Russia (Austria especially can offer help here and seem sincere) but it doesn't really matter, the fall moves are a killing blow:
Austria:
A Vie -> Gal (or HOLD if there's an Italian army in Tyrolia, but not really necessary)
F Tri -> Ven
A Ser S A Bul -> Rum
Turkey:
A Bul -> Rum
A Con -> Ank
F Arm -> Ank
The point of the double hedgehog! Both Turkey and Austria pick up a single build, but importantly, Budapest is free for an army build, and Ankara is free for a naval build. The self-standoff in Ankara ensures Turkish dominance of the Black Sea, and the capture of Sevastopol by the end of 1902. Russia will almost certainly cover Sevastopol. If instead he supports himself into Rumania, he is still lost, and build-less in the south. Best possible Russian moves (A Ukr -> Rum, F Bla S A Ukr -> Rum) still net Russia nothing unless he was able to get Sweden -- and with a Russian fleet in the Black Sea after the spring moves, the chances that Germany would let Russia into Sweden are just about 0.
Take a look at this slow-motion catastrophe:
https://imgur.com/a/VwESANo builds for Russia, Austria is STILL completely safe, and Turkey now owns the Black Sea. The secret to the success of the alliance in 1902 is simple:
1. The Turkish army in Rumania needs to be supported into Galicia by the Austrian armies in Vienna and Budapest right away --- to extend the flank to the left, and prevent that army's destruction from the triple Russian attack incoming while still allowing A Con -> Bud.
2. Turkey must play to destroy the Russian fleet rather than to take Sevastopol by the end of the year. Usually, both can be accomplished by the end of 1903.
The end of Russia is inevitable at this point, and other powers will smell blood. Expect England to go all out to take StP -- it's over for the Bear already.
Looking Ahead:
For long-term success, the following rules are essential:
1. Total parity -- neither power gets to be more than one unit ahead of the other
2. Separate Natures -- turkey builds ALL fleets (with the exception of ONE more army to take and secure Moscow), and Austria builds ALL armies (with the exception of ONE more fleet to help him secure Naples)
3. Center Swapping with Greece and Rumania -- The first center swap is Rum-Greece: Rumania starts Turkish, and Greece starts Austrian. As both powers grow, these need to swap to make stabs harder and keep things even. As Austria begins to gobble up central centers in Germany, Greece and/or Rumania can be traded back to Turkey to keep things in parity.
Ultimately, Turkey has the easier time stabbing for the solo, but not by much. Usually England is the third power left in the west, and they can easily ally with Austria for a long see-saw. I find winning chances to be about equal with this monster, and I play it every chance I can.
Here's one example of how such a game can end:

Conclusion:
The Double Hedgehog is simple to play, safe, and requires little diplomacy in the early stages. A Turkey and Austria who trust each other and are feeling a good vibe can easily roll with it and ensure a strong finish. There is almost nothing that can be done to stop this strategy, because it looks so benign after the spring moves --- there is really no indication of what is coming, both sides look to be playing safe, separate, and defensive systems. Very few people know this strategy, and your opponents are unlikely to recognize it.
Reason to play as Turkey: Better winning chances than a juggernaut.
Reason to play as Austria: Eliminate Russia early, and you can always overwhelm the Balkans with armies if Italy is still alive and you decide to back out of the deal.
Anyways, give it a try. You might just be surprised at how fun and easy it is to crush with this basic system.