Even the best NBA teams (outside of Bill Russell's Boston Celtics teams in the 1960s) have trouble winning a title every year.
With injuries and super teams playing huge roles in today's NBA, it's not surprising that no team since the 2000-02 Los Angeles Lakers has managed to win three-straight championships.
Because of the way the game is now, the nearly two-decade run of dominance the San Antonio Spurs have been enjoying is even more impressive.
The Spurs, under coach Gregg Popovich, won their first-ever title in 1999 and now, nearly two decades later, are still one of the NBA's best teams.
That means the Spurs often find themselves locked in tough postseason battles, and this year is no different. Currently, San Antonio leads the Houston Rockets 3-2 in the best-of-seven Western Conference semifinals.
Though the Popovich-coached Spurs don't often blow series leads, it has happened in the past. In fact, the last two times San Antonio watched as 3-2 leads evaporated came in 2013 and 2015, framing the Spurs' 2014 title.
As the Spurs try to prevent that from happening again this postseason, with Game 6 coming in Houston on Thursday night, here's a look back at the last two series they blew leads. After all, those who don't learn from history, as they say, are doomed to repeat it.
2015: First-round loss to Los Angeles Clippers
A year after beating the Miami Heat in the NBA Finals, the Spurs were surprisingly mediocre during the regular season. They finished 55-27 and went into the playoffs as the No. 6 seed in the Western Conference.
That earned them a first-round date with the Los Angeles Clippers, who despite finishing with only one more win than the Spurs (56-26), earned the No. 3 seed and home-court advantage.
That advantage didn't matter much for the Clippers, as the Spurs jumped out to a 3-2 series lead, winning both Games 2 and 5 in Los Angeles.
However, Chris Paul and the Clippers rebounded, stealing Game 6 102-96 in San Antonio behind 26 points from Blake Griffin and 15 assists from CP3.
That led to a decisive Game 7 at the Staples Center in LA, where Paul exploded for 27 points, including a layup with one second left on the clock that gave the Clippers the 111-109 victory.
2013: NBA Finals loss to the Miami Heat
After winning Game 5 of the 2013 NBA Finals against LeBron James, Dwyane Wade, Chris Bosh and the Heat, the Spurs had to be feeling pretty good about themselves.
Holding a 3-2 lead, all they needed to do was pick up a win in either Game 6 or Game 7 in Miami to claim the franchise's fifth NBA title.
However, as we all know, that wasn't meant to be. Holding a 75-65 lead at the end of the third quarter in Miami in Game 6, the Spurs watched as the Heat chipped away at their deficit.
Still, with a 94-89 lead with only 28 seconds left, it appeared as if the Spurs had the game won. Then, though, LeBron hit a three and the Heat fouled Leonard, who made one of his two shots to give the Spurs a 95-92 lead.
That's when Ray Allen took over, hitting a game-tying three with 5.2 seconds left after Bosh grabbed a crucial offensive rebound.
In overtime, the Heat managed to claw their way to a 103-100 win, sending the series to a decisive Game 7, which Miami won 95-88 to comfortably claim their second-straight title.
Things worked out OK for Leonard and the Spurs, though, as they came back the next year and beat the Heat in five games, effectively ending the Big 3 era in Miami as LeBron went back to Cleveland following the season.