What could possibly go wrong? I know the temptation is to say: "Anything! They're the Cubs! LOL. Goats!" This isn't that.
Going into 2016, we can make two reasonable assumptions about the Cubs: 1. They are, as of now, the best team in baseball. 2. It's still far more likely that one of the other 29 teams in baseball will win the World Series.
A couple of years ago, Russell Carleton calculated how good a playoff team, once in the playoffs, would have to be to have better than 50 percent odds of winning the World Series. His answer? They'd have to be a 113-49 team. That's happened twice since baseball expanded to a 162-game season in 1961. The 1998 Yankees won 114 games and the World Series; the 2001 Mariners won 116 games and lost in the American League Championship Series. (See? 50 percent. The math is perfect.)
"There will never be an overwhelming favorite in the playoffs," Carleton writes. "A team that was practically perfect in every way would still only be a 50/50 shot to win the World Series."
Or look at it another way. FanGraphs gives the Cubs a 94 percent chance of making the playoffs. That's astonishingly high. They have a 52 percent chance of repeating last year's trip to the National League Championship Series. (They're the only team above 50 percent; the Dodgers are the only team with a better than 40 percent chance, and they're at 41 percent.)
Their odds of winning the World Series? 18.5 percent, says FanGraphs. Baseball Prospectus likes the Cubs less, giving them a 12.3 percent chance to win the World Series, 0.3 percentage points lower than the Dodgers. (See note.)
So, really, there are an infinite number of things that could go "wrong" for the Cubs.
Take last year. The Cardinals lost their ace, Adam Wainwright, for most of the season; they lost two of their cornerstone veterans, Matt Holliday and Yadier Molina, for long stretches; and their best prospect died before the season started. And yet they won 100 games, forcing the Cubs into the wild-card game, probably because of extreme luck.
Injuries are the most obvious form of bad luck. But the Cubs have built a deep team, too. Jorge Soler, whose ceiling could be that of an All-Star, is essentially a reserve outfielder. Javier Baez, as ESPN's Christina Kahrl told me, could start at shortstop on a number of teams and put up 20-plus home runs. Instead, he's a super-sub. Starters like Ben Zobrist and Kris Bryant can play multiple positions. Travis Wood and new acquisition Adam Warren essentially give the Cubs seven starting pitchers. Even assuming a typical run of injuries, the team has built in enough flexibility and resilience to mitigate the loss of a star with minimal falloff.
It helps that they're good across the board. As I found in my season preview, per FanGraphs's projections, the Cubs have a top-10 player at every position but catcher and center field, including at all five starting-pitcher slots, and the bullpen as a whole. Even then there's reason to believe that Miguel Montero could be better than the 15th-ranked catcher (because, as explained in the piece, he's a great pitch framer) and that Dexter Fowler will be better than the 20th-ranked center fielder (because the projections assume a ton of regression from his career year in 2015, from 3.2 WAR to 1.8 WAR).
It's just a great team; a 97-win team in 2015 that added two key pieces from their divisional rivals. They could be even better in 2016—but then again, neither Baseball Prospectus nor FanGraphs projects them to win more games than last year. If you're really looking for weaknesses, there are more tangible things than curses.
Rizzo and Bryant probably won't be as clutch this year.
There are a number of different statistics that measure how well players perform during key moments in games—when a hit (or an out) greatly changes the probability a team will win a game. Anthony Rizzo and Kris Bryant were among the league leaders in all of these. Win Probability Added? Rizzo was first in major league baseball, Bryant fifth. RE24 ("run expectancy based on 24 base-out states")? Rizzo was fourth, Bryant ninth. "Clutch," which measures "how much better or worse a player does in high leverage situations than he would have done in a context neutral environment"? Bryant was fifth, Rizzo 10th.
Players develop reputations for being good in clutch situations, but the consensus is that being "clutch" isn't a skill; Rizzo and Bryant may fare well in the clutch because they are good hitters, and more likely to get a hit at any given point, but it's unlikely that they automagically get even better in high-leverage situations. Having two players be across-the-board leaders in all the leverage statistics a second year in a row is unlikely, which could mean more dead rallies in 2016.
Kris Bryant's BABIP was too high.
As with his performance in the clutch, Bryant may have benefited from some good luck across the board in 2015. His batting average on balls in play—BABIP—was .378, fifth-highest in the majors. So almost four out of ten times Bryant put the ball in play, he got a hit.
The problem is that players just don't sustain that kind of BABIP, year in and year out, over a career. Take the Tigers' Miguel Cabrera, who finished second last year with a .387 BABIP. He's arguably the best, most complete hitter of his generation, and he sustains a high BABIP for someone who's not particularly fast—.348 over his career. But it swings up and down: .384 last year, .346 the year before that, .356 three years ago, then .331, then .365.
Paul Goldschmidt of the Diamondbacks might be Cabera's heir apparent, and he's also faster than Cabrera. Last year he had a .382 BABIP. The year before that, though, it was .368, then .343. Joey Votto, another one of the game's most skilled pure hitters, had the sixth-highest BABIP in 2015, and the second-highest cumulative BABIP from 2010-2015: .361. Like Goldschmidt and Cabrera, Votto is a remarkably consistent hitter, but his BABIP has ranged from .349 to .404 in his (non-injury-riddled) seasons as a major leaguer.
And it makes a difference. The year Votto had a .349 BABIP, he hit .309 with a .416 OBP; the year he had a .404 BABIP, he hit .337 with a .474 OBP. It can mean the difference between a very good season and a great one. And Bryant's projections look good next year, but both FanGraphs and Baseball Prospectus predict his on-base percentage and batting average will fall about 10 points each. Reportedly Bryant has worked on his swing in order to reduce his biggest weakness, a 30.6 percent strikeout rate that was third-worst in baseball. If he can make more contact, he could maintain his average and on-base percentage even if his BABIP falls, but he'll need to replace some of last year's luck with skill.
Jake Arrieta's BABIP was too low.
Just as batters can benefit from luck on balls in play, pitchers can as well. Pitcher Jake Arrieta rode a .246 BABIP to a 1.77 ERA. That was the third-lowest BABIP among qualified pitchers; number two was Zack Grienke, who had a .229 BABIP and a 1.66 ERA.
Those are freakishly low BABIPs for a starting pitcher. Clayton Kershaw has averaged a .268 BABIP from 2010-2015; Chris Sale, .294; Felix Hernandez, .289. And Arrieta is a ground-ball pitcher, so you'd expect a somewhat elevated BABIP.
And the fact that Arrieta is a ground-ball pitcher presents another interesting wrinkle. As Eno Sarris flagged at FanGraphs earlier this month, ground-ball pitchers tend to age worse, beginning around 30 years old—and Arrieta just turned 30 this month.
This doesn't mean that Arrieta is in for a bad year; all expectations are that he'll be one of the best pitchers in baseball. FanGraphs projects him for a 2.76 ERA, Baseball Prospectus for a 3.09 ERA. Either would be very good, and given the quality of the Cubs' offense, would be more than enough for him to have a shot at 20 wins for a second straight season. But a second straight season with an ERA under two seems like an unrealistic expectation—which means that, unfair as it seems to say, he'll be worse in 2016.
How good is Kyle Schwarber?
The early promotion of the 2014 draft pick pushed the Cubs over the top, but the trends weren't great. His on-base plus slugging was .982 in June, .900 in July, .861 in August, and .741 in September and October. His weighted runs created plus (wRC+) fell, from 160 to 151 to 133 to 111. That 111 wRC+ is still above average; even hitting just .208 in September/October, Schwarber had a .354 OBP, thanks to his patience at the plate.
Like Bryant, he strikes out a lot and walks a lot; like Bryant, he can still be expected to have a good 2016, but not without growing pains. As Caitlin Swieca points out at Baseball Prospectus Wrigleyville, Schwarber still isn't good enough at hitting left-handed pitchers to avoid a platoon. It's to the front office's credit that a platoon is a realistic solution, but surely cold comfort for Schwarber.
How good are the Cubs?
They are a better team than they were last year, with the additions of Jason Heyward, John Lackey, Ben Zobrist, and Adam Warren, but that doesn't mean they'll win more games. They're probably the best team in baseball, but they probably won't win the World Series, at least in the most literal sense of "probably."
All they can do is construct a team that's deep enough for the long grind of the regular season and front-loaded with enough elite talent to be competitive in the short series of the playoffs. And most important, good enough to survive some bad luck. That, they've done.