The best (and worst) free agent signings in MLB history

Key Points:

• Baseball free agency celebrated its 50th anniversary, tracing its origins primarily to pitcher Andy Messersmith's landmark free agency status on March 16, 1976, following a historic legal challenge that overturned baseball's reserve clause.
• The article ranks the 25 most successful free agent signings over the past 50 years, led by Barry Bonds' 1993 deal with the Giants, which produced an extraordinary 109.1 bWAR over 14 years, highlighting the transformative impact of free agency on player movement and team building.
• Other notable top free agent signings include Greg Maddux to the Braves (1993), David Ortiz to the Red Sox (2003), and Randy Johnson to the Diamondbacks (1999), all of whom delivered exceptional on-field performance and value relative to their contracts.
• The analysis also identifies the 11 least successful free agent contracts, with Kris Bryant's 2022 deal with the Rockies and Barry Zito's 2007 contract with the Giants ranking among the worst due to poor performance and negative value relative to salary.
• The ranking methodology incorporates aggregate and average player performance (bWAR), win probability added, championship contributions, and economic efficiency adjusted for inflation and era, providing a comprehensive evaluation of free agent contract success over five decades.