Adding the final line gets a nice list format that you can transform to a data.frame
require(RCurl); require(stringr); require(rjson)
#download data from numberfire
nf <- "https://www.numberfire.com/nba/fantasy/fantasy-basketball-projections"
html <- getURL(nf)
#extract json variable (?)
pat <- "NF_DATA.*}}}"
jsn <- str_extract(html, pat)
jsn <- str_split(jsn, "NF_DATA = ")
fromJSON(jsn[[1]][[2]])