Reason for optimism: There isn't another team in baseball that wouldn't trade its roster (contracts included) for the Cubs'.
Reason for pessimism: It's nearly impossible for Jake Arrieta to provide as much value in 2016 as he did in 2015, but it doesn't matter.
In 33 starts last year, Arrieta allowed a total of 52 runs -- the same amount the Phillies' Justin De Fratus allowed ... out of the bullpen. But that figure is actually deceivingly high because of the way they were distributed. In terms of win expectancy, the best way to allow your runs over the course of a season is to bunch them all in one game. Arrieta didn't do that, of course, but he did allow a total of zero or one run (earned and unearned) in 15 of his last 20 starts (and 20 out of 33 overall). Zack Greinke may have edged Arrieta for the ERA crown, but not even he had a 20-game stretch of starts that gave his team such an overwhelming chance to win.
Therefore, it's safe to say Arrieta will suffer some regression this year. But any increase in his runs allowed has a decent chance of being offset by the addition of John Lackey. While four-fifths of the 2015 rotation that all made at least 30 starts returns for Chicago, Lackey replaces a collection of six different hurlers who filled the fifth starter role to the tune of a 4.56 ERA in 34 starts and didn't even average five innings an outing. Lackey, of course, is no "fifth starter"; his remarkable durability (at least 27 starts in 11 of the past 12 seasons and never fewer than 24) means the vast majority of those replacement-level innings, including those from the long relievers, are retired.
With Arrieta, Jon Lester and Lackey typically going seven innings, if Chicago's bullpen usage is primarily limited to two- or three-inning outings, the Cubs are in very good shape with Justin Grimm, Pedro Strop and Hector Rondon pitching the high-leverage innings. Only an injury, or probably two, stands in the way of the Cubs' staff allowing fewer runs in 2016 than 2015.
Of course, the Cubs are the betting favorite to win the World Series because of their projected work on the run-suppression side of the ledger. Given the era of run scoring we're in, Chicago has amassed an enviable roster of still-peaking, under-27-year-old talent. With their depth, youth and above-average offensive talent at every single position, there's nary a scenario I can envision that doesn't have the Cubs leading the National League in scoring, most probably lapping the field similar to the 2013 Cardinals, who scored 783 runs, 77 more than their closest competitor and nearly 100 more than any team not playing half its games at Coors Field.
All of this was evident last June when the Cubs finished giving starts to place-holder veterans and finally got Kris Bryant, Kyle Schwarber, et al. into the starting lineup full time. I loudly called for the Cubs to not only win the most games in the majors in the second half of the season, but for them to improbably catch the Cardinals and Pirates as well. They just fell short of the outrageous latter goal, but they achieved the former, going an MLB-best 53-28 over their last 81 games. With so many factors affecting a team's projected win expectancy in any single game, it's almost always foolish to issue a blanket betting recommendation, but blindly taking the Cubs in every second-half game was an exception last year.
There's one other item to take a look at, and that's the subtlety of pitch framing. Baseball Prospectus has pioneered the valuation of pitch framing, and last year, the Cubs had made a huge upgrade from Welington Castillo and John Baker to Miguel Montero and David Ross. Based on their body of work prior to 2015, that switch was projected to be worth nearly 40 runs, as the called-strike deficit under Castillo and Baker of nearly 20 runs would turn into a surplus of about the same amount with Montero and Ross. That's exactly what happened, and rather than just talking about the value of pitch framing as an intangible, I now incorporate those fully into the projection. As it relates to the Cubs this year, if you're a daily bettor, keep this in mind: When the Cubs use Schwarber as a spot starter behind the plate, you may want to bet on the over.
Coming into this season, everyone on both sides of the betting counter has rightfully caught up with the Cubs' expectations, or so I had thought. When the Atlantis in Reno, publishers of the first season win totals, listed the Cubs at 89 wins, I nearly called Uber to inquire about helicopter service to The Biggest Little City. Days later, the Westgate established a far more reasonable market of 93.5 wins, and that's where we'll see the market right until the first pitch on Opening Day.
I, however, am not deterred by the big number, telling any skeptical friend from Chicago, like the price of a share of Warren Buffet's Berkshire Hathaway, "it's high for a reason." In fact, I have to go back to the 2011 Phillies, who had a wins total of 97 (and subsequently won 102), to find a team that I consider this bulletproof.
Raise the W, my friends in Wrigleyville -- this is your NL pennant winner.
2016 projection: 96-66 (first, NL Central)
Bet recommendation: Over