For perhaps the first time all season, the Chicago Cubs find themselves in real trouble. After Chicago lost 6-0 to the Los Angeles Dodgers in Game 3 of the NLCS on Tuesday night, FiveThirtyEight’s Elo predictions dropped the Cubs’ chances of winning the series to 40 percent, thus giving them a mere 25 percent probability of ending the franchise’s 108-year championship drought. Going back through Elo’s archives on a weekly basis, it’s the first time since the week of July 13 — and only the second week all season — that Chicago hasn’t been the favorite to win the World Series.

As you might expect, it took a surprising confluence of events to put the Cubs in these straits. Game 3 starter Jake Arrieta had his worst postseason start as a Cub — and the 17th-worst start of his Chicago career, period — giving up four earned runs in five innings while posting a meager 41.3 game score that ranked worse than all but 18 percent of his starts all season. (For reference’s sake, an average game score is 50, and opposing starters average a 49.1 mark against the Dodgers.) Since undergoing the transformation that mutated him from a replacement-level pitcher to an elite ace three seasons ago, Arrieta has seldom had an outing as poor as the one he turned in Tuesday, and it could scarcely have come at a worse time.

The Cubs’ bats are also running unusually cold. They’ve been shut out in two consecutive games — the first time that’s happened all year to a Chicago team that scored the third-most runs in baseball during the regular season — and LA starters Clayton Kershaw and Rich Hill averaged a collective game score of 75.8 against the Cubs over the past two games, the second-best run of back-to-back starts opponents had against Chicago all season. (On May 17, Milwaukee Brewers starter Chase Anderson posted a 72.6 game score against them, a game after Gerrit Cole of the Pittsburgh Pirates had a masterful 86.6 game score.)

If so inclined, Cubs fans could spin all this in a positive direction: A rare combination of sloppy pitching and punchless hitting was required to put Chicago in its current 2-1 NLCS hole, and neither of those trends is likely to persist going forward. In fact, our Elo model considers the Cubs slim favorites in each of the series’ next two games (despite both being staged at Dodger Stadium), and they need to win only one of those to guarantee at least one more matchup at Wrigley Field, where Elo has them as more sizable 60 percent favorites. That’s why their current 40 percent Elo odds are slightly better than the historical average (37 percent) for teams with home-field advantage who found themselves in a 2-1 hole. This series probably hasn’t reached its denouement just yet.

But there’s also some statistical evidence that the Dodgers’ edge may consist of more than just that 2-1 series lead. The sabermetric website FanGraphs.com assembles depth charts for each team, adding up the talent on each roster in terms of wins above replacement (WAR). And according to their estimates, the Dodgers currently have more WAR of talent in their depth chart (58.3) than the Cubs do on theirs (54.8), with the difference primarily coming between the starting rotations. Now, that’s just one source; most other rating systems (including Elo) have consistently considered Chicago the best team in baseball. But it does keep the discussion open over how much of the Cubs’ incredible .255 batting average on balls in play allowed was due to fielding, luck or pitching skill — the answer to which could matter a lot going forward.

Either way, as it stands now the Cubs are facing their biggest moment of adversity in the season to date. They didn’t fold when they could have during the Division Series; now let’s see whether they can respond against the Dodgers with a World Series berth on the line.