If you bet on sports long enough, you will eventually see it all. You will experience some of the worst beats you could ever imagine. You will bet on teams that will snatch a loss from the jaws of victory. If it happens often enough, it will leave you swearing off sports betting forever. Of course, you will be back in action the next day. Why? Avid sports bettors are the ultimate optimists.

Much to the chagrin of sports bettors who might have been on the wrong side, here’s a look at some of the biggest NBA Playoffs upsets. For a little extra spice, a few other upsets in other sports warrant some mention.

2011: Memphis Grizzlies Vs San Antonio Spurs (NBA)

Heading into the 2011 Western Conference playoffs, the San Antonio Spurs were loaded with talent. As the number one seed, they featured the big three, Manu Ginobli, Tony Parker, and then future Hall of Fame center Tim Duncan. The Memphis Grizzlies had a blue-collar lineup that featured small forward Zach Randolf.

The key to this series was the absence of Ginobli in game one. The Grizzlies took advantage of his absence and squeaked out a 101-98 victory. After losing game two in San Antonio, the Grizzlies were able to sweep the three games at home to secure the series upset. They eventually lost to Oklahoma City in the next series, but the upset of the Spurs stands as a historical stunner.

1975: Washington Bullets Vs Golden State Warriors (NBA)

Heading into the 1975 NBA Finals, the Washington Bullets were heavily favored to dismiss the Golden State Warriors. The Bullets enter the playoffs with a record of 60–22 and cruised through the Eastern Conference playoffs. From the West came the Warriors with a record of 48–34. They made it through the Western Conference playoffs, but it wasn’t easy. What was about to take place was mind-boggling.

In game one, the Bullets jetted out to a 14 point lead only to have the Warriors come roaring back for a victory. The story was much the same in game two, leaving the Bullets in a tough spot as they headed to the West Coast for the next two games. Behind the relentless scoring of then-future Hall of Famer Rick Berry, the Warriors closed the deal at home for an amazing four-game sweep of the Wes Unseld-led Bullets. This still stands as the biggest four-game upset in NBA Finals history.

2011: St. Louis Cardinals (MLB) Win World Series

Heading into the last three weeks of the 2011 MLB season, the St. Louis Cardinals had no chance to win the Central Division. What they did have was a longshot chance of getting a Wild Card spot. To get to the Wild Card spot, the Cardinals would have to catch the Atlanta Braves, who were 4.5 games ahead of the Cardinals.

Bookmakers decided the Cardinals had no chance to win the World Series. To make their point, bookmakers posted the Cardinal at 999 to 1 to take the 2011 World Series Title.

Much to the chagrin of bookmakers, the Braves fell apart over the last 15 games while the Cardinals went 11-4. That was good enough for the Cardinals to earn the coveted Wild Card spot.

When the Cardinals buzzed through the NL playoffs to claim the NL Pennant, some people in Vegas got nervous. Conversely, some very lucky or astute sports bettors started getting that tingly feeling that comes with a potential big score. Dramatically, the Cardinals beat the Texas Rangers in the World Series in seven games. The drama hit a fever pitch in game six when David Freese hit a walk-off home run in the 11th inning.

It was rumored that one bettor bet the Cardinals at the 999 to 1 mark and returned to claim his winnings of $250,000.

1999: St. Louis Rams (NFL) Shock Bookmakers With Super Bowl Victory

For much of the 1990s, the Los Angeles Rams stood as the NFL’s favorite punching bag. After scoring QB Trent Green in the offseason, Rams fans were hoping for a winning season. Bookmakers had other ideas as they posted the Rams at 300 to 1 to win the Super Bowl.

It was a bad sign for Rams bettors when Green went down with a season-ending injury before the season even started. On a move that screamed desperation, the Rams called on Kurt Warner to QB the team. This was a head-scratcher since Warner was not even in the league at the time he got the call. What ensued over the next 16 weeks was nothing short of miraculous.

The press called it the “Greatest Show on Turf.” To the naked eye, it was simply one of the greatest exhibitions of offense in NFL history. Warner led the Rams to a regular-season record of 13-3. It was the first time in NFL history that a team scored 30 or more points on 12 occasions. All Warner did was pass for 4,353 yards and 41 TDs. His final QB rating of 109.2 stands as one of the best QB ratings in NFL history.

In the playoffs, the Rams looked like men playing against boys. With juicy odds of 300 to 1 awaiting the brave bettors who believe in the Rams from the beginning, Super Bowl XXXIV was a nail-biter. After Warner hit WR Isaac Bruce with a 73 yard TD pass, the Tennessee Titans came up a yard short of winning. They were stopped on a one-yard rush with the clock running out.

As sports bettors lined up to collect their bounty, they hopefully tipped their hat to the blue-collar Warner. All he did in the Super Bowl was set a then Super Bowl record of 414 yards passing. He still holds the record for most pass attempts without an interception at 45 attempts.