"Trimmed" is a term meaning
"scammed" back in the 1920's usually by a
confidence man. The goal of a confidence game was typically to "trim a
mark" for example.
In this context the author was probably saying that not only did they
get beaten, they got beaten bad in what appeared to be a "rigged game".
Thanks for the info. So is he saying it was rigged or that the only way they could win 5
times in a row was if it was rigged? ;). It is interesting how slang and even common words
change meaning and connotation over the years so that one generation reading something
even as recently as a 100 years ago would run into issues.