Can Pedro Strop be the Cubs closer for a playoff run?

Earlier this year I took a look at the stats and salaries of the Cubs bullpen. My takeaway was that the bullpen had been a big plus for a rotation that had faltered at times, but that Cubs fans should be a bit wary since it looked like they were riding a bit of luck. Despite the injury to Cubs closer Brandon Morrow I’ve been cautiously optimistic about the bullpen as we look ahead to the rest of September and October. After all, a bit of rest before the stretch run would probably be good for Morrow. Drew Smyly’s rehab appears to be on schedule and he’d be an additional quality arm out of the pen. Then, earlier this week in Joe Maddon’s pregame press conference he dropped this news about Morrow:

Carrie Muskat’s piece gives us some more information:

“We’re very much aware of [the time],” Maddon said Wednesday. “We’d love to have him back. Even when he does come back, if it is toward the end, how do you utilize that because you can’t push him two days in a row? That impacts the rest of the group. These are the things we have to consider.”

Maddon also acknowledged that it changes the way games are managed and who works where:

It will make it tougher.

”When you have an anchor, that one guy at the end, who can get the three plus outs, you can manage the game differently,” Maddon said. “It’s like how we used Wade last year in Washington. If you don’t have that, you have to manipulate it. Does it become more difficult? It probably does. But it can be done.”

It’s worth nothing Maddon’s pragmatic responses here and I don’t want to overhype this problem. It’s also worth noting that Morrow will throw off a mound this weekend so the Cubs will have a better idea of his prognosis. We’ll leave aside the fact that the injury was originally listed as biceps inflammation and now is being described as a “bone bruise with two small strains” because that’s a post for another day. Today I want to acknowledge that the bullpen looks different with a designated closer, and there is a very real chance the Cubs won’t have one in September and October. With that in mind I wanted to take an updated look at the Cubs bullpen, what the Cubs need from their pen down the stretch and a look at Pedro Strop as a possible closer.

Bullpen Stats

Let’s start with an overview. The Cubs pen is great by some measures, good by others and average by a few. Just like the last time we checked in there is probably some luck involved in some of these numbers. Take a look for yourself.

By ERA the Cubs have the second-best bullpen in the National League and they are fifth overall. That’s excellent, news although it’s a bit of a falloff from the last time I checked in when they were third. In May when I looked at these numbers the bullpen ERA was 2.71, since then it’s increased to 3.36. That’s a pretty big jump, but the good news is that while the FIP, xFIP and BABIP have increased, they haven’t jumped nearly as much. In May the pen’s FIP was 3.71 compared with 3.81 now, xFIP was 4.01 compared with 4.25 now, and BABIP was .263 compared to .277 now. That indicates that this is a bit of the pen regressing to it’s mean. The not-so-good news is that the bullpen is still overperforming what we’d expect to see given these numbers, so the pen is still getting a little lucky.

By metrics that are more advanced than ERA, things don’t look nearly as great for the Cubs. The bullpen ranks 10th overall in FIP, 20th overall in xFIP and 14th overall in WAR. Those numbers give me pause. The best and luckiest version of this Cubs bullpen can probably make a run in September and October. An unlucky version of this bullpen could have real problems down the stretch. The version in between would probably make it to the postseason but struggle in the playoffs.

The Cubs’ Needs

The Cubs played 140 games. They have 83-57 record and a 4½-game lead in the NL Central. That translates to a .593 win percentage over the 2018 season. A .593 win percentage over their final 22 games would translate to a 13-9 record over that period and 96 wins for the Cubs. For the Brewers to get to 96 wins they’d need to go 17-4 over the same period. The Cardinals have played one fewer game than the Brewers and would need to go 18-4 over the same period. That’s a .810 win percentage for the Brewers and an .818 win percentage for the Cardinals. Possible? Sure. Likely? Probably not. So it seems reasonable that if the Cubs play the way they’ve played so far, for the rest of the season, they will win the division.

With that in mind, let’s take a look at how the pitching has broken down between starters and relievers over the course of the season:

The good thing about these numbers is that they look sustainable, and the starting rotation has been improving. For example, 1271⅓ innings across 140 games translates to starters going about 5.4 innings per game and relievers picking up about 3.6 innings (approximatly, extra-inning games shift these numbers a bit, but not much). As I mentioned earlier, the gap between reliever ERA and FIP is decreasing and the BABIP looks more sustainable.

A look at the Cubs’ bullpen by month shows that while the pen is undoubtedly stronger with Morrow in it, the Cubs record hasn’t been dramatically impacted by his absence. Remember that Morrow has had two stints on the DL this year, one in late June and the second since July 15.

Full disclosure, those September numbers don’t look great. However, it’s a very small sample size and the numbers are overly impacted by the 11-1 drubbing the Cubs took from the Brewers on Tuesday.

Pedro Strop - Closer

The overall numbers actually look pretty good and sustainable, which means there are only two question left: Can Strop close down the stretch and in the playoffs? And do the Cubs have a plan if he can’t? The first thing I wanted to look at was Strop compared to other closers. However, teams approach the ninth inning differently, trades and injuries change players roles over the course of the season and some managers prefer to mix and match. To account for that I sorted relievers by saves and created a table of all relievers with at least 10 saves to see how Strop compares:

While Strop’s 2.37 ERA compares favorably to other closers, it’s overperforming his FIP by more than a point. His BABIP of .226 looks due for a regression and he doesn’t strike out nearly as many batters as other pitchers in the closing role. In fact if you were just looking at K/9 and ERA the Cubs have other pitchers (Carl Edwards Jr., Justin Wilson and Steve Cishek) who look better suited to the role.

But let’s be honest, that’s not all we are looking at and I don’t want to see one of those guys close ahead of Strop any more than you do. A look at Strop’s splits by month reveals why:

Obviously these numbers come with a huge small sample size warning. No reliever throws a ton of innings each month and Strop is no different. However, I’m particularly impressed with the minuscule batting average against him since him moved to the closer’s role and his strand rate. Morrow went on the DL in mid-July and Strop sort of settled into the closer spot shortly thereafter. Since July 15 batters are hitting .167 off Strop and he’s stranded 88.5% of all runners. While I’m still a bit nervous that his 2.41 ERA is outperforming his 4.71 FIP by a lot in that time span, the results play.

Additionally, while the situation isn’t ideal, the Cubs’ bullpen is built for this. The following relievers have all closed in the last three years for other teams: Cishek, Wilson, and Brandon Kintzler. If Strop’s numbers fall off a cliff, there are a few guys who could step into that role. Finally, remember, the Astros won a World Series with Ken Giles as their nominal closer, and Strop is certainly performing better than that.

Takeaways

The current bullpen situation for the Cubs isn’t ideal but Pedro Strop has stepped up in a big way in Brandon Morrow’s absence. If for some reason that changes down the stretch, Maddon has a lot of options to get the Cubs to the playoffs. Would it be better to have a solid, designated closer? Absolutely. But the Cubs have all the tools to make it work even if Strop struggles at some point, this just makes things more interesting.

One final thought, I would love nothing more than a lights out closer run from Pedro Strop. He’s been one of the most solid members of the bullpen since the Cubs traded for him. Plus, closers are often kind of quirky by nature and Strop has that covered. Beyond Strop-themed road trips, I’m pretty excited about Cubs faithful embracing #HatsLeft as a rally cry down the stretch and into October.