Free labor has the inspiration of hope; pure slavery has no hope.
—Abraham "Nunez" Lincoln

You call yourself free? I want to hear your ruling thought and not that you have escaped a yoke. Are you such a one as was permitted to escape a yoke? There are some who threw away their ultimate worth when they threw away their servitude. Free from what? What is that to Zarathustra! But your eyes should announce to me brightly: free for what?
—Friedrich "Fat Freddie" Nietzsche

Free agency, we are told, was engendered by Curt Flood's staunchly refusing to report to the Phils, then seen as an unfriendly team towards African-American players, after an October 7, 1969 trade with the Cards. Flood's refusal led to the end of reserve-clause slavery, and eventually to Jay Bell's ludicrous contract with the Diamondbacks in their inaugural year.

Of course, there were free agents before Flood. They just couldn't declare themselves free on their own. They had to get the team to let them go, which wasn't always the best career move. In the primordial history of the game, players would sign one-year contracts and "revolve" to another at the end of the year. Or he would just "jump" one contract for another. As the reserve clause took hold and rival leagues signed agreements to honor each other's contracts, jumping became less of an issue. However, it would crop up every so often when a new rival league would appear, and one time—the Players' National League in 1890—the players actually organized the league themselves.

Anyway, Retrosheet has data on free agents and contract jumpers going back to the launching of the American League as a major league. Given the new tools that Studesand I developed for studying transactions, we can take a look at the best free agents of all time. So without further ado…

First, we'll look at the greatest free agent signings based upon performance with the new team. This is based on the Win Shares Above Baseline (WSAB) each player had with the new team. Also listed are the players' Win Shares with the new team and his previous career Win Shares and WSAB:

Bonds is the best and he can only add to that. You probably noticed that there are a couple of players on the list from the before the dissolution of the reserve clause. Also, most of these players had substantial career before they became free agents except for Cecil Fielder, who, of course, took a circuitous loop through Japan. Finally, you'll note that Biggio and Williams are the only ones on the list who re-signed with their previous teams.

The list wouldn't be complete of we overlooked the contract jumpers of the past:

You may note that there are almost as many jumpers with the necessary 60 WSAB for their new teams in the three years of the NL-AL wars as there were free agents with the same amount over the last forty years of free agents.

Here's quick rundown by season of all free agents and jumpers. You'll note that there is a second wave of jumping during the major-league war with the Federal League 191-15. Also note how the number of free agents has been climbing especially in the last decade. (Retrosheet only has transaction data through 2002):

Next, we'll try to quantify the value of the free agent by joining the trade data with Doug Pappas's salary data.

Other entries in the Trade Series:

Mike: I'll Take Manhattan: Baseball's Most Lopsided Trades: Parts I, I (revised), II

A Quick One (Happy Mike)

Lee Even Stevens: Parts I, II—The Sexy Version

Cain and A-Rod—A Bling-Bling Rivalry: Parts I, II

Kansas City Blues: Parts I, II

Baseball's Most Lopsided Trades—The Revenge of Glenn Davis

Awe-Phil?: Parts I, II, III

Gone With the Draft

Organizational Skills, Part I, II

The Best of Drafts, The Worst of Drafts

Studes: The Best and Worst Teams of the Trade

Smoltz for Alexander

The Biggest Deals of All Time

Sources:

Sean Lahman's Baseball Database

Retrosheet's Transaction Data