Ryuhei Yamaguchi has officiated 37 matches on record, averaging 2.2 cards and 1.2 fouls per game โ a lenient official. A player is dismissed roughly once every 19 games, and the spot is pointed to 0.24 times per match. Home teams win 30% of matches under him, drawing 27% and losing 43%. Most active in the J3-League (37 matches). 30% of his bookings come after the 75th minute, with the first card around the 40'. He cards more than 25% of J3-League 2024 referees.