Chicago Cubs: There are many reasons this is considered the worst trade in franchise history.
If you ever go up to a Cubs fan who is over 60 and you mention “Brock for Broglio” to them, you will guaranteed get a disgusted reaction. Back in early 1960s the Cubs had a young outfielder named Lou Brock. Brock as a young kid was a mediocre ballplayer who was eventually dealt to the St. Louis Cardinals for a package that was centered around a pitcher named Ernie Broglio in 1964.
Brock ended up playing 16 years in St. Louis and was inducted into the Hall of Fame in 1985. He finished with 3,023 hits, 938 stolen bases and a career .293/.343./.410 slash. Broglio pitched in 59 games as a Cub and posted a 5.40 ERA and 1.8 WHIP. This trade hurts real bad.
Brock played in 256 games against the Cubs and hit .334/.378/.479 with 20 homers, 103 RBI and an .856 OPS. He had more hits against the Cubs (342) than any other team he faced. In fact that is more hits than he had in his 327 games as a Cub (310). Safe to say Brock made sure the Cubs would not forget who they traded away.