Throughout baseball history, a team going through a lengthy rebuilding process isn't a strange sight. A franchise going through this process via a fire sale for financial reasons isn't even a product of the free-agency era. Many famous rebuilds, such as the mid-1910s Philadelphia Athletics, happened strictly for financial reasons.
With today's increased focus on concepts, such as the team success cycle, the word "tank" has started to appear in the lexicon where "rebuilding" was once used. And while tanks have their uses -- storing water, winning World War II -- the sports version of the word has a decidedly negative connotation.
Call it tanking or call it rebuilding, but teams do it because it works. There is little actual direct benefit to winning 80 games instead of 70 games in baseball -- not even a long-term attendance reward. But there is a benefit to winning 70 games instead of 80 games if you go there by trading those 10 wins for even more wins in the future for a year that may matter.
Which rebuilding cycles have been the most successful? To find the answer, I went through team and transaction data going back to 1976, the start of free agency, one of the largest things that changed how teams were constructed.