1978 Winning Percentage Leaders Top 25 in the American League
Name	Winning Percentage	Team	Rank
Ron Guidry	.893 (.89286)	New York Yankees	1
Larry Gura	.800 (.80000)	Kansas City Royals	2
Dennis Eckersley	.714 (.71429)	Boston Red Sox	3
Mike Caldwell	.710 (.70968)	Milwaukee Brewers	4
Fergie Jenkins	.692 (.69231)	Texas Rangers	5
Ed Figueroa	.690 (.68966)	New York Yankees	6
Jack Billingham	.652 (.65217)	Detroit Tigers	7
Rich Gale	.636 (.63636)	Kansas City Royals	8
Chris Knapp	.636 (.63636)	California Angels
Jim Palmer	.636 (.63636)	Baltimore Orioles
Luis Tiant	.619 (.61905)	Boston Red Sox	11
Jim Slaton	.607 (.60714)	Detroit Tigers	12
Dave Goltz	.600 (.60000)	Minnesota Twins	13
Lary Sorensen	.600 (.60000)	Milwaukee Brewers
Frank Tanana	.600 (.60000)	California Angels
Paul Splittorff	.594 (.59375)	Kansas City Royals	16
Dennis Martinez	.593 (.59259)	Baltimore Orioles	17
Don Aase	.579 (.57895)	California Angels	18
Mike Flanagan	.559 (.55882)	Baltimore Orioles	19
Dennis Leonard	.553 (.55263)	Kansas City Royals	20
Mike Torrez	.552 (.55172)	Boston Red Sox	21
Jon Matlack	.536 (.53571)	Texas Rangers	22
Scott McGregor	.536 (.53571)	Baltimore Orioles
Doc Medich	.529 (.52941)	Texas Rangers	24
John Henry Johnson	.524 (.52381)	Oakland Athletics	25
Name	Winning Percentage	Team	Rank

	Jim Thome wore number twenty-five since he first came up with the Cleveland Indians making him the franchise record holder for that particular number (Mike Garcia is second). Future Hall of Famer Sammy Sosa is best known for wearing number twenty-one; however, when the young slugger played for the Chicago White Sox (1989-1991) he only wore number twenty-five. The first player from the Angels franchise (they were the California Angels at the time) to wear the number twenty-five was Bob Perry.