They haven't officially clinched the NL Central title yet, but by taking three out of four games from the Brewers in Milwaukee this past weekend, the Cubs more or less wrapped it up. Up 5 1/2 games over the Brewers and six games over the Cardinals, their magic number is down to two; a win over the Cardinals in any of their next four games, and any loss by the Brewers will do the trick. While the Cubs won't come anywhere close to last year's 103 regular season wins, the reigning world champions own the league's best record since the All-Star break at 44-23, and shouldn't be taken lightly come the playoffs.
After ending their 108-year championship drought last fall, the Cubs brought back largely the same cast of characters for their title defense. Centerfielder Dexter Fowler, closer Aroldis Chapman, fifth starter Jason Hammel left in free agency, backup catcher David Ross retired, and filling the void were the likes of Jon Jay, Wade Davis and Brett Anderson. After part-time appearances in 2016, catcher Willson Contreras and outfielder Kyle Schwarber were primed for full 2017 seasons. Even so, out of the gate the Cubs experienced a greater championship hangover than most wild card-era teams. They went just 21–19 through the first quarter of the season, and were 43-45 at the All-Star break.
The team's problems weren't difficult to diagnose. The Cubs regressed in nearly every area of the game. A rotation that posted an MLB-best ERA of 2.96 last year turned in a 4.66 mark through the first half, accompanied by a 4.50 FIP. Returning members Jon Lester, Jake Arrieta, John Lackey and Kyle Hendricks all experienced significant dropoffs from last season, and Anderson logged an 8.18 ERA over six starts. In the lineup, Kris Bryant and Anthony Rizzo were the only full-timers with an OPS+ above 100 until Contreras heated up just before the break. Contreras, Schwarber Javier Baez and Addison Russell, who along with Bryant make up the lineup's young core, all drastically underproduced through the first half, as did veterans Jason Heyward and Ben Zobrist. Meanwhile, the defense, which last year led the majors with a .728 defensive efficiency, fell off considerably as well.
The crosstown trade that delivered Jose Quintana in exchange for a four-prospect package headed by slugging outfielder Eloy Jimenez paid instant dividends. The Cubs won their first six games of the second half and 14 of their first 17, producing an eight-game swing in the NL Central standings, from 5 1/2 games behind the upstart Brewers to 2 1/2 ahead. They've continued to play winning baseball since, going 17–12 in August and 14–8 thus far in September; only on August 12, when the Cardinals rode an eight-game winning streak into a first-place tie, did the Cubs relinquish sole possession of the top spot.
Quintana has pitched to a 3.50 ERA (127 ERA+) and 3.38 FIP in 13 starts as a Cub, an improvement upon his work prior to being dealt (4.49 ERA, 96 ERA+, 4.02 FIP) and helping anchor a rotation resurgence that has produced a 3.43 ERA and 4.08 FIP in the second half. Every starter but Lester has improved since the break, and not by a little, at least in terms of ERA:
First Half Games StarteD
First Half ERA
Second Half Games Started
Second Half ERA
Unlike last year, when all five regular starters made at least 29 turns and accounted for 152 out of 162 starts, injuries have been a significant factor for the rotation in 2017. Lester, Lackey and Arrieta have all made at least 29 starts but each served a brief DL stint. Lackey landed on the disabled list just before the All Star break due to plantar fasciitis in his right foot, Lester missed a couple of turns in late August due to shoulder fatigue, and Arrieta served a DL stint earlier this month due to a right hamstring strain. More significantly, Hendricks missed a month due to tendinitis in his right hand. Not shown here is the first-half work of both Eddie Butler (11 starts, 3.86 ERA) and Anderson (six starts, 8.18 ERA), the pair supplanted by Quintana's strong work.
For all of the rotation's improvement, the bullpen has become more of a concern. After producing a 3.26 ERA and 3.80 FIP in the first half, the unit has slumped to marks of 4.80 and 4.40, respectively, in the second. Davis has blown only one second-half save, but swollen walk and homer rates (5.4 and 1.9 per nine, respectively, compared to 3.6 and 0.3 in the first half) rate as causes for concern. Setup men Hector Rondon and Koji Uehara have been lit up for ERAs of 5.31 or above since the break, as has deadline acquisition Justin Wilson, who has walked 16 in 15 2/3 innings. Carl Edwards Jr.’s ERA has nearly doubled from first half (2.29) to second (4.08). Manager Joe Maddon could have his work cut out figuring how to get the ball to Davis come October.
On the other side of the ball, Jay and rookie outfielder/second baseman Ian Happ, who was called up in mid-May and helped offset Zobrist's struggles, are the only two of their 11 most frequently-used hitters to experience second half falloffs in terms of wRC+ (virtually identical to OPS+, with the added benefit of being tracked via FanGraphs’ splits).
First Half PA
First Half wRC+
Second Half PA
Second Half wRC+
Albert Almora Jr.
The table is a bit misleading since both Contreras and Russell have missed considerable time lately. Contreras homered five times in a seven-game span before missing a month in August and September due to a right hamstring strain and hasn't yet regained his stroke, but the acquisitions of Alex Avila (July 31 from the Tigers) and Rene Rivera (August 19 from the Mets) did enough to offset his absence. Russell only recently returned from a six-week absence with a right foot strain and a bout of plantar fasciitis. Baez started at shortstop in 41 of the 42 games during his absence while Happ and Zobrist split time at second base and Tommy La Stella provided depth. Thus, the most dramatic change probably belongs to Schwarber, who turned his season around after a two-week refresher course in Triple A, batting .171/.295/.378 with 12 homers through June 21 and .250/.337/.571 with 17 homers since returning on July 6. Just about everybody else has upped their game, including stars Bryant and Rizzo.
Through the first half, the Cubs scored and allowed exactly 399 runs, 4.53 per game. Since the All-Star break, the team has outscored opponents by 107 runs (384 to 277), with the offense pounding out an MLB-high 5.73 runs per game, and the pitching and defense yielding 4.13 per game. Their .645 Pythagorean winning percentage in the second half isn't quite up to last year's full-season mark of .665, but it's in the same ballpark.
Assuming they wrap up the division—the Baseball Prospectus Playoff Odds give them a 99.5% chance of doing so, as they'd have to go 0–7 while either the Brewers or Cardinals run the table—the Cubs will wind up with the third seed in the NL, facing the Nationals (94–61) while the Dodgers (99–57) square off against the wild card winner. They have their concerns heading into October, with Lester and the bullpen at the top of the list, but they look a whole lot more formidable than they did two and a half months ago.