-- Database schema
| players : player_id [ INT ] primary_key , first_name [ TEXT ] , last_name [ TEXT ] , hand [ TEXT ] , birth_date [ TEXT ] , country_code [ TEXT ] | matches : best_of [ INT ] , draw_size [ INT ] , loser_age [ INT ] , loser_entry [ TEXT ] , loser_hand [ TEXT ] , loser_ht [ INT ] , loser_id [ INT ] matches.loser_id = players.player_id , loser_ioc [ TEXT ] , loser_name [ TEXT ] , loser_rank [ INT ] , loser_rank_points [ INT ] , loser_seed [ INT ] , match_num [ INT ] , minutes [ INT ] , round [ TEXT ] , score [ TEXT ] , surface [ TEXT ] , tourney_date [ TEXT ] , tourney_id [ TEXT ] , tourney_level [ TEXT ] , tourney_name [ TEXT ] , winner_age [ INT ] , winner_entry [ TEXT ] , winner_hand [ TEXT ] , winner_ht [ INT ] , winner_id [ INT ] matches.winner_id = players.player_id , winner_ioc [ TEXT ] , winner_name [ TEXT ] , winner_rank [ INT ] , winner_rank_points [ INT ] , winner_seed [ INT ] , year [ INT ] | rankings : ranking_date [ TEXT ] , ranking [ INT ] , player_id [ INT ] rankings.player_id = players.player_id , ranking_points [ INT ] , tours [ INT ] |
-- -- Find the year that has the most number of matches.

SELECT YEAR FROM matches GROUP BY YEAR ORDER BY count(*) DESC LIMIT 1;