Deliberately-inefficient compared to what? TFA leads with:
> Swimmers and coaches began to realise that breaststroke was quicker when a swimmer recovered their arms forward above the water and the arm technique – as well as the swimming term ‘butterfly’ – was born.
This whole story somehow reminds me of the Fosbury flop technique in high jump -- amazingly, Dick Fosbury started to develop it at the age of 16: https://en.wikipedia.org/wiki/Dick_Fosbury#High_school_and_t...
From the Wikipedia article on Fosbury:
"The technique gained the name the "Fosbury Flop" when in 1964 the Medford Mail-Tribune ran a photo captioned "Fosbury Flops Over Bar," while in an accompanying article a reporter wrote that he looked like "a fish flopping in a boat." Others were even less kind, with one newspaper captioning Fosbury's photograph, "World's Laziest High Jumper""
I noticed the article pointedly didn't compare the stroke to the forward crawl, which is clearly both faster and more efficient.
There's no real way to compare the butterfly and the forward crawl that doesn't make the butterfly look like a ridiculous farce.
the butterfly stroke is the most energy-inefficient stroke, i believe, despite being quicker.