Goal contribution matrix for La Liga (2018-2019 Season)

laliga_goal_contribution_matrix.r

## pkgs
pacman::p_load(tidyverse, polite, scales, ggimage, ggforce,
               rvest, glue, extrafont, ggrepel, magick)
loadfonts()

## add_logo function from Thomas Mock
add_logo <- function(plot_path, logo_path, logo_position, logo_scale = 10){

    # Requires magick R Package https://github.com/ropensci/magick

    # Useful error message for logo position
    if (!logo_position %in% c("top right", "top left", "bottom right", "bottom left")) {
        stop("Error Message: Uh oh! Logo Position not recognized\n  Try: logo_positon = 'top left', 'top right', 'bottom left', or 'bottom right'")
    }

    # read in raw images
    plot <- magick::image_read(plot_path)
    logo_raw <- magick::image_read(logo_path)

    # get dimensions of plot for scaling
    plot_height <- magick::image_info(plot)$height
    plot_width <- magick::image_info(plot)$width

    # default scale to 1/10th width of plot
    # Can change with logo_scale
    logo <- magick::image_scale(logo_raw, as.character(plot_width/logo_scale))

    # Get width of logo
    logo_width <- magick::image_info(logo)$width
    logo_height <- magick::image_info(logo)$height

    # Set position of logo
    # Position starts at 0,0 at top left
    # Using 0.01 for 1% - aesthetic padding

    if (logo_position == "top right") {
        x_pos = plot_width - logo_width - 0.01 * plot_width
        y_pos = 0.01 * plot_height
    } else if (logo_position == "top left") {
        x_pos = 0.01 * plot_width
        y_pos = 0.01 * plot_height
    } else if (logo_position == "bottom right") {
        x_pos = plot_width - logo_width - 0.01 * plot_width
        y_pos = plot_height - logo_height - 0.01 * plot_height
    } else if (logo_position == "bottom left") {
        x_pos = 0.01 * plot_width
        y_pos = plot_height - logo_height - 0.01 * plot_height
    }

    # Compose the actual overlay
    magick::image_composite(plot, logo, offset = paste0("+", x_pos, "+", y_pos))
}

## webscrape soccerway
url <- "https://us.soccerway.com/national/spain/primera-division/20182019/regular-season/r47983/"

session <- bow(url)

team_links <- scrape(session) %>% 
  html_nodes("#page_competition_1_block_competition_tables_7_block_competition_league_table_1_table .large-link a") %>% 
  html_attr("href")

team_links_df <- team_links %>% 
  enframe(name = NULL) %>% 
  separate(value, c(NA, NA, NA, "team_name", "team_num"), sep = "/") %>% 
  mutate(link = glue("
                     https://us.soccerway.com/teams/spain/{team_name}/{team_num}/squad/"),
         stat_link = glue("{link %>% str_replace('squad', 'statistics')}"))

## for each team link:
player_name_info <- function(session) {
  
  player_name_info <- scrape(session) %>% 
    html_nodes("#page_team_1_block_team_squad_3-table .name.large-link") %>% 
    html_text()
}

num_goals_info <- function(session) {

  num_goals_info <- scrape(session) %>% 
    html_nodes(".goals") %>% 
    html_text()
  
  num_goals_info_clean <- num_goals_info[-1]
}

num_assists_info <- function(session) {

  num_assists_info <- scrape(session) %>% 
    html_nodes(".assists") %>% 
    html_text()
  
  num_assists_info_clean <- num_assists_info[-1]
}

team_goals_info <- function(session) {
  team_goals_info <- scrape(session) %>% 
    html_nodes("tr.first:nth-child(6) > td:nth-child(2)") %>% 
    html_text()
}

# BIG FUNCTION
laliga_stats_info <- function(link, statlink) {
  
  session <- bow(link)
  session2 <- bow(statlink)
  
  player_name <- player_name_info(session = session)

  num_goals <- num_goals_info(session = session)

  num_assists <- num_assists_info(session = session)
  
  team_goals <- team_goals_info(session = session2)
  
  resultados <- list(player_name, num_goals, num_assists, team_goals)
  col_names <- c("name", "goals", "assists", "team_goals") 
  
  laliga_stats <- resultados %>% 
    reduce(cbind) %>% 
    as_tibble() %>% 
    set_names(col_names)
}

## all at once
laliga_goal_contribution_df_ALL <- map2(.x = team_links_df$link,
                .y = team_links_df$stat_link,
                ~ laliga_stats_info(link = .x, statlink = .y))

laliga_goal_contribution_df <- laliga_goal_contribution_df_ALL %>% 
  set_names(team_links_df$team_name) %>% 
  bind_rows(.id = "team_name")
  
## clean
laliga_goal_contribution_clean_df <- laliga_goal_contribution_df %>% 
  mutate_at(.vars = c("goals", "assists"), 
            ~str_replace(., "-", "0") %>% as.numeric) %>% 
  mutate(team = team_name %>% str_replace_all(., "-", " ") %>% str_to_title,
         total_goals = as.numeric(team_goals)) %>% 
  group_by(team) %>% 
  mutate(total_assists = sum(assists),
         goal_contrib = goals/total_goals,
         ## as/tot_goals because looking at perspective of contrib to goals.
         ## Will be an underestimation as not all goals have assists.
         ## a.k.a. not looking at % of club assists assisted but % of club goals assisted
         assist_contrib = assists/total_goals) %>% 
  ungroup() %>% 
  select(-team_name, -team_goals)
  
## Description text
## Iago Aspas
desc_aspas <- "With 20 Goals from 12.47 xG, Iago Aspas greatly exceeded his xG as he heroically saved Celta Vigo from relegation yet again!"

## Jony   xA90 of 0.29 (tied 3rd highest, minimum 30 games)
desc_jony <- "With 10 assists amounting to 34% of Alavés' xA, Jony had his career-best season as he helped Alavés contend for a European place."

## Messi
desc_goat <- "With total contribution nearly double of the next best, 36 Goals from a xG of 26, etc. Messi led almost every metric in La Liga this season!"

## PLOT!
laliga_goal_contribution_clean_df %>% 
  ggplot(aes(assist_contrib, goal_contrib)) +
  geom_point(data = laliga_goal_contribution_clean_df %>%
                    filter(goal_contrib < 0.225 | assist_contrib < 0.125),
             color = "grey20", size = 4, alpha = 0.2) +
  geom_point(data = laliga_goal_contribution_clean_df %>%
                    filter(goal_contrib > 0.225 | assist_contrib > 0.125),
             color = "red", size = 4) +
  geom_hline(yintercept = 0.225, color = "grey20", alpha = 0.4) +
  geom_vline(xintercept = 0.125, color = "grey20", alpha = 0.4) +
  geom_text_repel(data = laliga_goal_contribution_clean_df %>%
                    filter(goal_contrib > 0.225 | assist_contrib > 0.125,
                           !name %in% c("Iago Aspas", "L. Messi", 
                                        "Jony", "Pablo Sarabia")),
                  aes(label = name, family = "Roboto Condensed", fontface = "bold"), 
                  seed = 15, size = 4, 
                  min.segment.length = 0, segment.color = "red",
                  point.padding = 0.5) +
  geom_text(data = laliga_goal_contribution_clean_df %>%
              filter(name == "Pablo Sarabia"),
            aes(label = name, family = "Roboto Condensed", fontface = "bold"),
            size = 4,
            nudge_x = -0.02, nudge_y = 0) +
  geom_mark_circle(aes(filter = name == "L. Messi", 
                       label = "Lionel Messi: GOAT",
                        description = desc_goat),
                    label.family = "Roboto Condensed", label.fontsize = c(16, 12)) +
  geom_mark_circle(aes(filter = name == "Iago Aspas", 
                     label = "Iago Aspas: The Hero of Vigo",
                        description = desc_aspas),
                    label.buffer = unit(10, "mm"), label.fontsize = c(16, 12),
                    label.family = "Roboto Condensed") +
  geom_mark_circle(aes(filter = name == "Jony", 
                       label = "Jony: El Glorioso", 
                       description = desc_jony),
                   label.buffer = unit(5, "mm"), label.fontsize = c(16, 12),
                   label.family = "Roboto Condensed") +
  scale_x_continuous(labels = percent_format(accuracy = 1),
                     breaks = c(0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3),
                     limits = c(0, 0.33)) +
  scale_y_continuous(labels = percent_format(accuracy = 1),
                     breaks = c(0, 0.1, 0.2, 0.3, 0.4, 0.5),
                     limits = c(0, 0.55)) +
  labs(title = "Goal Contribution Graph: La Liga (2018-2019 Season)",
       subtitle = "Goal Involvement (Goals and/or Assists) as Percentage of Total Club Goals",
       caption = glue("
                      Data: soccerway.com & understat.com
                      By: @R_by_Ryo"),
       x = "Percentage of Club Goals Assisted",
       y = "Percentage of Club Goals Scored") +
  theme_minimal() +
  theme(text = element_text(family = "Roboto Condensed"),
        title = element_text(size = 20),
        plot.subtitle = element_text(size = 16),
        plot.caption = element_text(size = 10),
        axis.title = element_text(size = 14),
        axis.text = element_text(size = 12),
        panel.grid.minor.x = element_blank()) -> laliga_goal_contribution_matrix

laliga_goal_contribution_matrix

## save
ggsave(plot = laliga_goal_contribution_matrix, 
       "../La Liga 2018-2019/output/goal_contribution_matrix_plot_laliga.png",
       height = 8, width = 10)

plot_logo <- add_logo(
  plot_path = "../La Liga 2018-2019/output/goal_contribution_matrix_plot_laliga.png",
  logo_path = "https://i.imgur.com/hBltz33.png",
  logo_position = "top right",
  logo_scale = 6)

image_write(image = plot_logo, 
            "../La Liga 2018-2019/output/goal_contribution_matrix_plot_logo_laliga.png")