The Cubs' stars need to play like stars if they're going to hold off the Brewers

What’s wrong with the Chicago Cubs?

As a vital series in Milwaukee looms next week, the question occupies the North Side. The Cubs have given up the NL Central lead they held for more than half the season. The team that had not lost a series all year to a sub-.500 team has now lost two of their last four to such clubs, one of them unthinkably at home.

They confront a classic trap series on the South Side against a rag tag outfit they slaughtered three times two months ago by a cumulative score of 26-8…but one that has won five of its six games since the All-Star break.

Entering that Milwaukee series, losses to the White Sox would be slip-ups of banana peel proportions. Especially since the Brewers - 14-4 this month - appear incapable of losing to anybody.

The reason the Cubs are so vulnerable right now is actually pretty simple…and it doesn’t involve Ben Brown. OK, some of it does involve Brown, but not most of it. In simple terms, most of the Cubs’ stars have quit playing like stars.

In that vein, the table below will be enlightening. From best to worst, it lists the Win Probability Added for each of the nine Cubs regulars since July 1, a stretch where the team has played just-okay 11-7 ball.

A word of explanation regarding Win Probability Added. It is a calculation of each player’s impact on team success or failure on a game-by-game basis. A single at the critical moment of a close game can bring a bigger reward than a home run in a blowout. With 0.0 as a starting point, the higher the player’s WPA, the more positive has been his contribution to success. The opposite is of course also true.  

Cubs' biggest names have come up short as Brewers keep surging

These are fairly damning numbers for a serious contender, especially the one at the bottom, so let’s begin there. For all the MVP campaigning that has swirled around him this summer, Crow-Armstrong has – this month anyway –actually been a net liability to team success. At a time when stars need to play like stars, PCA appears to have begun a potentially costly retreat toward the land of average.

Crow-Armstrong has played in 17 of his team’s 18 games since July 1. But in 10 of those 17 games, his impact has been harmful to the cause. That seems unlikely given his July numbers, which sound pretty darned good, especially that .304/.333/.667 slash line.

The only plausible explanation, which happens to be true, is that PCA has done most of his damage in blowouts. He had a four-hit game – two of them homers -- on July 4 against the Cardinals, a game the Cubs won 11-3. He got three hits – two more of them homers -- July 10 against the Twins, in an 8-3 Cubs win.   

PCA has six home runs this month. But five of them came in victories that were attained by a combined margin of 25-4.  In his team’s seven July losses, PCA is batting .130. In games decided by one or two runs, his average is .125.

So the first thing the Cubs need is for Pete Crow-Armstrong to play like an MVP candidate at MVP moments.

Enough beating up on the Golden Boy. Unlike PCA, fellow All-Star Kyle Tucker does have a positive July WPA number (.145), but only very modestly so. In fact of the 29 players who have seen playing  time this month, the Cubs driving force  -- the guy they traded three good players for and the guy who is expected to bring upwards of a half billion on the open market this fall – only ranks 12th on his own team in July productivity.

But like Crow-Armstrong, Tucker has lapsed toward average. Tucker has played in 17 games, but also like PCA his negative impacts (9) outnumber his positive ones (8). His monthly slash line is .196/.310/.345. He’s hitting .191 in one or two-run games, .200 in losses.

The numbers make clear what we all understand instinctively: for the Cubs to go, they need meaningful productivity from Tucker AND Crow-Armstrong. Not surprisingly, they are 4-0 this month in games in which both stars generate positive contributions. They’re even 5-2 when just one of the pair makes a positive impact.

But they are just 1-4 in games where both stars come up negative in WPA. And as an editorial observation, the fact that the Cubs’ two big threats have both produced negative impacts in five of the 16 July games in which they have jointly appeared is its own condemnation.

The contrast with the Brewers is stark. Milwaukee’s lineup includes no All-Stars and few names widely recognized outside Wisconsin. Yet the Cubs’ most productive regular in July – Busch at .463 – would rank a weak fourth in the Brewers' lineup for July productivity, well behind Andrew Vaughn (1.451), Jackson Chourio (1.052) and Brice  Durbin (.722).

What do the Cubs need to shake their July doldrums, put the White Sox in their place and deal appropriately with the Brewers? Pitching, yes. But first and foremost, they need meaningful production from Crow-Armstrong and Tucker. In short, they need their stars to play like stars.