The Chicago Cubs defeated the Los Angeles Dodgers in Game 4 of the 2017 NLCS, giving the defending champions a glimmer of hope that they’ll be able to do the impossible. After falling into a 3-0 series hole, the Cubs will try to beat L.A. in four straight games and reach the World Series.

Technically, winning the series isn’t impossible. It’s been done before, and in the most shocking way imaginable. The Boston Red Sox rebounded from a 3-0 ALCS deficit to beat the New York Yankees in 2004, overcoming years of losing and the idea that they were cursed from ever winning a championship.

But that’s where MLB’s history of such comeback stories ends.

In 35 tries, no other team has ever lost the first three games of a series and gone on to win the series. Only two other teams have even forced a Game 6 after dropping Games 1-3.

After winning Game 3, the Dodgers were given -2300 betting odds to win the NLCS, via OddsShark.

If anyone knows about historic comebacks, it’s Dodgers’ manager Dave Roberts. He sparked Boston’s comeback—and New York’s collapse—by scoring the tying run in the ninth inning of Game 4 to keep the Red Sox’s hopes alive.

“I think that was a once-in-a-lifetime thing. Teams can't do that anymore," Roberts jokingly told reporters before Game 4 at Wrigley Field Wednesday. “No, it was a special group (Boston). It was a very lax group but professional. Obviously we were written off, but we did a good job of trying to focus on that game at hand and not getting ahead of ourselves.

“But it also takes some luck involved too. Because I think if you look back in that series, there are a lot of plays and things that could have gone a different way that went in our favor. But, yeah to win four straight games was tough. But it took a special team that we had in 2004.”

Chicago Cubs
Kris Bryant #17, Addison Russell #27, Javier Baez #9, and Anthony Rizzo #44 of the Chicago Cubs meet during a pitching change in the seventh inning against the Los Angeles Dodgers during game four of the National League Championship Series at Wrigley Field on Oct. 18, 2017 in Chicago. Jonathan Daniel/Getty Images

If anyone can duplicate what the 2004 Red Sox did, maybe it is this Cubs’ team. Chicago didn’t win four straight games a year ago, but they did come back from a 3-1 series deficit to beat the Cleveland Indians in the World Series. The Cubs closed out the series with one victory at Wrigley Field and two more in Cleveland, winning their first title since 1908.

Trying to win three straight games while bearing the weight of 108 years of losing was arguably a more difficult task than what lies ahead of Chicago now.

The Dodgers can punch their ticket to the World Series with the best pitcher in baseball on the mound Thursday night. Clayton Kershaw pitched well enough in the regular season to win his fourth NL Cy Young award. When he retires, he could be recognized as the greatest pitcher in MLB history, and he’s the reason that Los Angeles is favored to win Game 5 on the road.

Kershaw and the Dodgers have some playoff demons of their own. It’s been 29 years since L.A. last won a pennant. This Dodgers’ team, specifically, has come up short in the playoffs, winning the NL West in every year since 2013 and never making an appearance in the Fall Classic.

Heading into the NLCS, Kershaw had the worst ERA of any pitcher that’s made at least 12 career playoff starts. He pitched five innings and gave up two runs in the series opener, and he was pulled from the game before he could get credit for the win.

L.A. is supposed to win this series. They led MLB with 104 wins and swept the Arizona Diamondbacks in the NLDS. The Dodgers are sending their ace to the mound against a team that’s scored just seven runs in the last four games.

The pressure is on Kershaw and the Dodgers. to close out the series. It will only grow if the Cubs can send the series back to Los Angeles.

“I feel like there’s no pressure on us,” Cubs center fielder Albert Almora said, via Sports Illustrated. “There’s pressure on them to finish the job.”