Jörg Knappen wrote on Mon, Dec 5, 2011 08:54 AM UTC:
I looked up patsy in the OED, it is attested in 1889, postdating the german
use of Patzer.
I assosciate the word Patzer to the Viennese coffee house chess culture,
where chess master earned money playing against Patzers. It is the age of
Steinitz (one generation before Einstein and Lasker) or even ealier.