Prussia successfully attacked and occupied Austrian Silesia in 1740 and managed to hold it against Austrian counterattack until the end of the century.
Prussia, even after Frederick, was able to threaten Austria into halting its war on Turkey circa 1789-1791.
Prussia took a major beating from Napoleon, but so did Austria.
Both came back to take part in the final victorious anti-Napoleon coalition. The Prussian Blucher was the leader of the team beating Napoleon at Waterloo.
So the scoreboard for military performance from 1740-1815 would give Prussia a higher score than Austria.
But, from 1815 through 1866, Austria was always considered the favorite to win any Austro-Prussian conflict, until the Prussians surprised everybody at Sadowa.
In discussions of Prussia in the 19th century, Prussia is often being described as always being weaker than its opponents and only reforming and advancing enough militarily in the nick of time to win the fights they had in 1866 and 1870. The implication being, if they had any of those fights any earlier, they would have lost.
It makes it hard to trace out what the line-graph of Austrian strength versus Prussian strength would look like through the 1700s and 1800s.
If Prussia was weaker for that 19th century period in relative terms than the 18th century, why was that?
Or was Prussia not actually weaker? It was perhaps just more timid, cautious and critical of its own shortcomings, but probably capable of militarily outperforming Austria over most of this time?