His challenge led to free agency .
But recall St. Louis center fielder Curt Flood 's challenge in the early 1970s to MLB 's reserve clause , which essentially indentured players to their teams for life .
Curt Flood 's challenge led to free agency .
But recall St. Louis center fielder Curt Flood 's challenge in the early 1970s to MLB 's reserve clause , which essentially indentured players to their teams for life .