Not sure if the tag I've selected is appropriate. Feel free to correct.
I've googled gambit and got the definition as depicted below. Then, I folded out the frame to see see the usage graph and it stroke me as odd that the popularity of the term dropped around 1800 and then rearose in mid 1950's.
Why is it so? Has the raise any connection to WW2 or the Cold War? Any thoughts on the fall of popularity two centuries ago?
Or is it perhaps due to the way that the popularity is computed?