R/understat_match_stats.R

In JaseZiv/worldfootballR: Extract and Clean World Football (Soccer) Data

#' Get Understat match stats table data
#'
#' Returns the Stats values for a selected match from Understat.com.
#'
#' @param match_url A `character` string with the URL of the match played.
#'
#' @return returns a `data.frame` with data from the stats table for the match.
#'
#' @details For `draw_chances`, `home_chances` and `away_chances`, values below 10% in the browser will be retrieved as NA (e.g. A "5%" chance will be NA in the `data.frame`).
#'
#' @importFrom magrittr %>%
#' @importFrom rvest html_elements html_text
#'
#' @export

understat_match_stats <- function(match_url) {

  match_stats <- .get_understat_json(page_url = match_url) %>%
    rvest::html_elements("div.scheme-block.is-hide[data-scheme='stats']") %>%
    rvest::html_elements(".progress-value") %>%
    rvest::html_text()

  away <- match_stats[seq(1, length(match_stats), by=2)]
  home <- match_stats[seq(2, length(match_stats), by=2)]

  match_stats <- data.frame(

    match_id = as.integer(gsub("[^0-9]", "", match_url)),

    home_team = as.character(away[1]),
    home_chances = as.integer(gsub("[^0-9]", "", away[2]))/100,
    home_goals = as.integer(home[3]),
    home_xG = as.numeric(home[4]),
    home_shots = as.integer(home[5]),
    home_shot_on_target = as.integer(home[6]),
    home_deep = as.integer(home[7]),
    home_PPDA = as.numeric(home[8]),
    home_xPTS = as.numeric(home[9]),

    draw_chances = as.integer(gsub("[^0-9]", "", home[2]))/100,

    away_team = home[1],
    away_chances = as.integer(gsub("[^0-9]", "", away[3]))/100 ,
    away_goals = as.integer(away[4]),
    away_xG = as.numeric(away[5]),
    away_shots = as.integer(away[6]),
    away_shot_on_target = as.integer(away[7]),
    away_deep = as.integer(away[8]),
    away_PPDA = as.numeric(away[9]),
    away_xPTS = as.numeric(away[10])

  )

  return(match_stats)
}