Free agency in the NBA can sometimes swing the balance of power in the league. The right free agents could bolster a team’s playoff aspirations or even turn some into title favorites.Team executives covet free agents. Unless it’s a sign-and-trade deal, they don’t have to give up assets to acquire a player to boost their respective lineups.ESPN Stats & Info@ESPNStatsInfoOn this day in 2016, Four-time scoring champ Kevin Durant, a sought-after free agent, announces on The Players’ Tribune that he will sign with the Golden State Warriors.78645On this day in 2016, Four-time scoring champ Kevin Durant, a sought-after free agent, announces on The Players’ Tribune that he will sign with the Golden State Warriors. https://t.co/tajmDPmKlVWhen Kevin Durant joined the Golden State Warriors from free agency in 2017, NBA history changed. The Dubs added two more to their haul, making KD a two-time champ. At the same time, they also deprived LeBron James of golden opportunities to catch up with Michael Jordan’s title collection.From 2000 to 2010, five free-agent signings helped change the history of teams in the league.#5, Steve Nash signs with the Phoenix Suns (2004)Steve Nash was a two-time All-Star, a two-time All-NBA team member and helped carry the Dallas Mavericks to the Western Conference Finals in 2003.Mavericks team owner Mark Cuban, however, refused to give his star point guard the kind of money he deserved in free agency. The billionaire would later admit that failing to secure “Nashty” was the biggest mistake of his ownership with the Mavs:"That's my biggest mistake ever. Not even close, my biggest mistake ever. He had been injured the year before and his minutes were declining, and our doctor was like, 'He may have some issues.' And coach [Don Nelson] was like, 'He may have some issues.' So we made him what we thought was a great offer, but then Phoenix came in and just beat that offer."Alex Kennedy@AlexKennedyNBAOn @EtanThomas36's "The Rematch," Mark Cuban (@mcuban) said that he regrets letting Steve Nash leave the Mavericks to sign with the Suns."That's my biggest mistake ever. Not even close, it's my biggest mistake ever. Nash hated me for a long time because of it. We're good now."152On @EtanThomas36's "The Rematch," Mark Cuban (@mcuban) said that he regrets letting Steve Nash leave the Mavericks to sign with the Suns."That's my biggest mistake ever. Not even close, it's my biggest mistake ever. Nash hated me for a long time because of it. We're good now." https://t.co/diIn2vMZdjDallas went to the 2006 NBA Finals but lost to the Miami Heat after leading 2-0. One has to wonder if the Mavericks could have been a champion earlier if they had retained Steve Nash.On the other hand, Nash’s presence in Phoenix made the Suns elite title contenders. They just couldn’t get over the hump over the San Antonio Spurs on numerous occasions. Nash led the league in assists five times and the NBA MVP twice in his eight-year stint in Phoenix.#4, Chauncey Billups signs with the Detroit Pistons (2002)The Detroit Pistons after years of first-round exits following their glory years in the late ‘80s and ‘90s, reached the Eastern Conference semis in 2002. They traded Jerry Stackhouse, the main guy that brought them there to the Washington Wizards for Richard Hamilton in the summer of that year.The move, however, that most analysts consider was the most crucial during that time was the free agency signing of Chauncey Billups. Before he earned the nickname “Mr. Big Shot,” the point guard played for four teams in five years.Pro Sports Outlook@PSO_SportsJuly 17, 2002: Chauncey Billups signed a 5y/$35M deal with the Detroit #Pistons as a free agent. Billups would lead Detroit to their 3rd championship in franchise history while being named Finals MVP in just his 2nd season with the team in 20045July 17, 2002: Chauncey Billups signed a 5y/$35M deal with the Detroit #Pistons as a free agent. Billups would lead Detroit to their 3rd championship in franchise history while being named Finals MVP in just his 2nd season with the team in 2004 https://t.co/MaVetccCviAfter jumping from the Boston Celtics, Toronto Raptors, Denver Nuggets and Minnesota Timberwolves, Billups found a home in Detroit. Together with Rip Hamilton, Ben Wallace, Corliss Williamson and Cliff Robinson, the Pistons reached the Eastern Conference Finals for the first time since 1991.In 2004, the Pistons replaced coach Rick Carlisle with Larry Brown and traded for Rasheed Wallace. Detroit beat the Indiana Pacers in the conference finals and pulled off one of the biggest upsets in NBA Finals history.The Pistons dispatched the Shaq-Kobe Lakers in just five games. Chauncey Billups won NBA Finals MVP. The Lakers broke the O’Neal-Bryant tandem the following season while the Pistons went to five more conference finals.