Database schema:

CREATE TABLE divisions (
	division TEXT NOT NULL -- example: ['D1', 'B1'],
	name TEXT -- example: ['Division 1A', 'Bundesliga'],
	country TEXT -- example: ['Deutschland', 'Belgium'],
	PRIMARY KEY (division)
)


CREATE TABLE matchs (
	"Div" TEXT -- example: ['D1', 'B1'],
	"Date" DATE -- example: ['2020-08-08', '2020-08-09'],
	"HomeTeam" TEXT -- example: ['Antwerp', 'Club Brugge'],
	"AwayTeam" TEXT -- example: ['Mouscron', 'Charleroi'],
	"FTHG" INTEGER -- example: ['0', '1'],
	"FTAG" INTEGER -- example: ['0', '1'],
	"FTR" TEXT -- example: ['A', 'D'],
	season INTEGER -- example: ['2020', '2021'],
	CONSTRAINT fk_matchs_divisions FOREIGN KEY("Div") REFERENCES divisions (division)
)

Question: What's the winning rate of Club Brugge in the 2021 Premier League?
Evidence: Premier League is name of division; season = 2021; Club Brugge is name of team; Club Brugge wins implies HomeTeam = 'Club Brugge' and FTR = 'H' and AwayTeam = 'Club Brugge' and FTR = 'A'; DIVIDE(SUM(COUNT(FTR = 'H' where HomeTeam = 'Club Brugge', name = 'Premier League', season = 2021), COUNT(FTR = 'A'where AwayTeam = 'Club Brugge', name = 'Premier League', season = 2021)), COUNT(Div where name = 'Premier League', season = 2021));

SQL:
SELECT CAST(COUNT(CASE WHEN T1.FTR = 'H' THEN 1 ELSE NULL END) + COUNT(CASE WHEN T1.FTR = 'A' THEN 1 ELSE NULL END) AS REAL) * 100 / COUNT(t1.FTR) FROM matchs AS T1 INNER JOIN divisions AS T2 ON T1.Div = T2.division WHERE T1.season = 2021 AND T1.AwayTeam = 'Club Brugge' OR T1.HomeTeam = 'Club Brugge'