Richard Sharp's Game of Diplomacy.
Historically, the Anschluss was the annexation of Austria by Germany on 11 March 1938; as such, it may seem an odd name for a pro-Austrian opening! However, the German word doesn’t necessarily (or even usually) imply rape the union may be voluntary on both sides, and in this context will be. The essence of the idea is that Germany and Austria play as a single country during the period of their initial vulnerability; and, more specifically, Germany will come to Austria’s assistance if the latter is attacked by Italy and! or Russia.
I think I can claim to have discovered the Anschluss, or at least to have been the first to formulate the idea clearly. What first put it into my mind was a random check on the many disasters that have overtaken Austria in Diplomacy: clearly, if Italy and Russia decide to take Austria apart, with or without Turkish assistance, only Germany can do anything to prevent it. Austria’s record is horrific : in the first 230 completed British postal games, Austria failed forty-three times to achieve the modest performance of surviving until 1904! What is revealing is Germany’s performance in those games: one win, four draws, one second, two equal seconds, seven thirds, one equal third, eight fourths, one equal fourth, six fifths, four equal fifths, seven sixths, and one magnificent seventh, when Germany managed to go out in 1902, a year before Austria. So in the forty-three Austrian disaster games, Germany won 2.3 per cent and drew 9.3 per cent; in the other 187 games Germany won 14.4 per cent and drew 12.3 per cent. To put it more simply, in games where Austria fails, Germany has the worst record of any country; where Austria lasts until 1904 or later, Germany has the best record. Yes, I know the dangers of drawing conclusions from small samples, but I cannot believe that this is all coincidence.