$ perl chain_transform.pl
         Rate  fea   fa fser  fsr   fs
fea  199110/s   --  -8% -60% -68% -69%
fa   216392/s   9%   -- -57% -66% -67%
fser 499367/s 151% 131%   -- -21% -23%
fsr  628278/s 216% 190%  26%   --  -4%
fs   651987/s 227% 201%  31%   4%   --