W.Pct. Year Team W L
0.600 Kennedy 1903 PIT NL 9 6
0.583 McGinnity 1905 NY1 NL 21 15
0.567 Walsh 1906 CHA AL 17 13
0.500 Mullin 1907 DET AL 20 20
0.471 Chalmers 1915 PHI NL 8 9
0.462 Mays 1922 NYA AL 12 14
0.400 Ruether 1926 NYA AL 2 3
0.400 Hallahan 1934 SLN NL 8 12
0.300 Trout 1940 DET AL 3 7
0.250 Heintzelman 1950 PHI NL 3 9
For those who also read SABR-L, skip below which is the leaders in worst and best Win% for WS starters
W.Pct. Year Team W L
0.250 Heintzelman 1950 PHI NL 3 9
0.300 Trout 1940 DET AL 3 7
0.308 Anderson 2001 ARI NL 4 9
0.333 Russo 1943 NYA AL 5 10
0.350 Bevens 1947 NYA AL 7 13
0.350 Avery 1995 ATL NL 7 13
...
0.900 Ford 1950 NYA AL 9 1
0.905 Maddux 1995 ATL NL 19 2
1.000 Blackwell 1952 NYA AL 1 0
1.000 Lestejo01 2007 BOS AL 4 0
1.000 Bystrom 1980 PHI NL 5 0
1.000 Mails 1920 CLE AL 7 0
Clem Comly
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W.Pct. Year Team W L
0.250 Heintzelman 1950 PHI NL 3 9
0.300 Trout 1940 DET AL 3 7
0.308 Anderson 2001 ARI NL 4 9
0.333 Russo 1943 NYA AL 5 10
0.350 Bevens 1947 NYA AL 7 13
0.350 Avery 1995 ATL NL 7 13
...
0.900 Ford 1950 NYA AL 9 1
0.905 Maddux 1995 ATL NL 19 2
1.000 Blackwell 1952 NYA AL 1 0
1.000 Lestejo01 2007 BOS AL 4 0
1.000 Bystrom 1980 PHI NL 5 0
1.000 Mails 1920 CLE AL 7 0
Clem Comly
___