The Cubs Are Finally Putting Their Run Differential To Good Use

The National League Central is the weirdest division in baseball. It’s the only one where the first place team has a negative run differential. It’s also the only one where the second place team has a negative run differential. Indeed, only one team in the division has scored more runs than they’ve allowed, and it’s the third-place Chicago Cubs at 51-51.

With a +55 run differential, the Cubs rank third in the National League, better than teams like the Giants, Diamondbacks, Phillies, and Marlins, and, of course, ahead of the Brewers, Reds, Cardinals, and Pirates. Only three NL clubs have outscored the Cubs, and only six have allowed fewer runs to cross the plate. Only one has done both: the Atlanta Braves. Yet while the Braves have the best World Series odds in baseball, the Cubs’ chances of claiming a title are just a teeny tiny bit worse:

By Pythagenpat and BaseRuns, the Cubs “should” be 57-45. According to the calculation of Pythagorean win-loss record at Baseball Reference, the Cubs “deserve” to be 56-46 this season, five games better than they are right now. That record still wouldn’t be quite enough to put them ahead of the Brewers, but it would bring them within half a game of the division and into first place in the Wild Card standings. Unfortunately for Chicago, Pythagoras doesn’t have much of a say in the postseason race. With a .500 record, the Cubs are four games back of a Wild Card berth, and they’d have to leapfrog at least three teams to get there. Their playoff odds sit at 21.5%, putting them behind the Brewers and Reds in the NL Central, as well as the Phillies, Giants, Marlins, Diamondbacks, and even the Padres in the Wild Card chase. They recently surpassed the Mets, but with the way New York is playing, that isn’t saying much.

Thus, the Cubs were widely thought to be sellers for the upcoming deadline, especially before they took eight of their last nine and tripled their postseason odds. Cody Bellinger and Marcus Stroman looked like they’d be two of the best players on a thin trade market, and with so many teams looking to buy, Chicago could have brought back some promising prospects. Now, of course, the Cubs are far less likely to sell, but things could still go either way, even with their recent run of success. Bellinger, especially, will be highly sought-after, and it’s possible Jed Hoyer gets an offer too good to refuse.

All of this raises a simple question: How did the Cubs end up in such a spot despite their impressive run differential? After all, scoring more often than you’re scored against is generally a recipe for success in sports.

The Cubs have blown 21 leads, but they also boast 22 comeback wins, per Baseball Reference. Meanwhile, their 10-12 record in one-run games is bad but not atrocious. On top of that, they haven’t faced any more position players pitching than the average team, and in fact, they rank dead last in run value produced against position players, per Baseball Savant. They also rank ninth-last in run value with a position player of their own on the mound. Clearly, they aren’t padding their stats in non-competitive at-bats.

The Cubs have been on the winning end of blowouts more often than not, and they’ve shut out their opponents more often than they’ve been shut out. That said, even if you remove the blowouts (5+ runs), they still have a +13 run differential, or a .520 Pythagorean expected winning percentage per Baseball Reference’s calculation. If you remove the shutouts, they still have a +25 run differential and a .526 winning percentage. All this to say, the Cubs haven’t just run up their run differential with a few lopsided victories. And even if they had, it’s not entirely fair to look at the numbers without blowouts and shutouts – that’s how good teams win.

It is worth noting that several of Chicago’s most lopsided victories came in April, while most of their worst losses were in May. To that point, it’s interesting to break down their season month by month. The Cubs burst out of the gate in April, winning 14 of their first 24 before finishing the month with three straight one-run losses in Miami. That sweep set off a dreadful month of May, in which they went 10-18. This time, however, they ended the month on a strong note against a different team from Florida, taking two of three from the Rays. That success carried over into June and July, and since then, the Cubs have gone 27-20.

At first glance, Chicago’s run differential in each month tells a similar story: good in April, bad in May, and good again in June and July. Yet upon closer inspection, you’ll discover a cavernous gap between their expected and actual winning percentages in the first month of the season:

Since May 1, the Cubs are 37-38 with a +12 run differential. They have a .493 winning percentage and a .516 expected winning percentage. Those figures aren’t so far apart! Over 75 games, that’s only a difference of a two wins (and it was even closer before last night’s blowout against the Cardinals). However, in April alone, the Cubs underperformed their Pythagorean winning percentage by four wins. They had a +43 run differential yet a mere 14-13 record. Only the Pirates (+48) had a better run differential during the first month of the season, but while Pittsburgh had a 20-9 start to show for it, Chicago was just a single game above .500 when the calendar flipped to May.

When the Cubs lost in April, it was usually a close contest, and when they won, they really won. In wins, they had an average margin of victory of 5.6 runs; in losses, they were outscored by only 2.7 runs per game. They won by more than five in half of their victories but lost by more than five only once. That kind of dominance is unsustainable, but that doesn’t make it any less impressive. What’s more, the Cubs weren’t just beating up on weaker adversaries. They played seven games against the Dodgers and also faced the Brewers, Reds, Rangers, Mariners, Padres, Marlins, and Athletics. Only two of those teams are below .500, and only one is a genuinely easy opponent.

That being said, the Cubs did absolutely demolish the A’s, outscoring them 26-3 in a three-game set. They scored six runs against Kyle Muller (career 6.50 ERA, 5.10 FIP), four against Adrián Martínez (6.09 ERA, 5.07 FIP), five against Adam Oller (7.09 ERA, 6.66 FIP), and three against Trevor May, who went on the injured list the very next day. That certainly skewed Chicago’s run differential for the month. Still, the Cubs deserve credit for taking down a bad team, and it’s not as if the Reds and Brewers didn’t also get their shot against Oakland. Cincinnati outscored them 18-14, taking two of three, while Milwaukee was swept in three games and outscored 15-9. More to the point, the Cubs still had a .583 expected winning percentage in April even excluding those games against the A’s. In contrast, their actual winning percentage was just .458 without those three victories. The Cubs played great baseball in April, and not just when facing the worst team in the league.

At the same time, there is more to be said about the Cubs beating up on bad teams. Entering last night’s game, they had the eighth-best record in the majors against teams with a losing record, and the eighth-worst against opponents at or above .500. Moreover, they had a +92 run differential against losing teams (only trailing the Rays and Rangers), but a -44 run differential against winning teams (22nd in baseball). The offense ranked fifth with an .809 OPS against teams below .500 and 18th with a .698 OPS against teams above .500. Similarly, the pitching staff ranked fifth and 19th, respectively, with a .638 OPS allowed to opponents above .500 and a .748 OPS allowed to those below. Funnily enough, however, the Cubs have underperformed their expected record against both good teams and bad. By Pythagorean expectation, the Cubs should have two additional wins against teams below .500 and three more against teams above. In other words, this still doesn’t explain why the Cubs have underperformed their run differential to such a great extent.

Ultimately, the whole thing boils down to clutch performance in April. The Cubs had the best offense in the NL during the first month of the season, but they came up short in high-leverage spots. Their clutch score was a league-worst -4.30; that’s far and away the worst clutch score any team has had in any month this season. The starting rotation let them down too, although not to such an extreme degree. They had the fifth-best ERA and ninth-best FIP but the worst clutch score in the league. No matter how good your team is, you’re not going to win ballgames if you don’t produce at the right moments.

As disappointing as it is that the Cubs cost themselves those victories in April, things are starting to get better. Performing in the clutch hasn’t been a problem for Chicago since the start of June. Their .574 winning percentage is quite close to their .597 expected winning percentage, and a .574 winning percentage has been good enough for an NL postseason berth in each of the past seven years. If poor timing was really this team’s biggest problem, they still have hours in the day to fight their way back.

Not to mention, it certainly helps that the Cubs have the easiest remaining schedule in the National League. According to our playoffs odds page, their upcoming opponents have an average neutral-opponent winning percentage of .484. Meanwhile, other Wild Card contenders like the Giants, D-backs, Phillies, and Marlins all have a remaining strength of schedule above .500. Considering how well the Cubs have performed against weaker opponents this year, this is particularly welcome news.

The Chicago Cubs have had a weird season in the most bizarre division in baseball. Despite boasting the best run differential in the NL Central, they’ve been an afterthought for most of the year. Finally, however, they’re starting to look more normal, and not a moment too soon. The trade market will lose some big names if the Cubs hold onto Bellinger and Stroman, but baseball is always better when more teams are trying to win.