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Dereck Rodríguez will try and prove that ERA still matters

A year removed from a rookie season that featured a dramatic gap between his ERA and xFIP, Rodríguez will seek to prove that he’s the real deal.

Los Angeles Dodgers v San Francisco Giants Photo by Lachlan Cunningham/Getty Images

Delving into Dereck Rodríguez’s Fangraphs page is the baseball equivalent of ardently writing in your diary. It invites you - forces you, even - to be honest with yourself about your feelings, your values, and your purest baseball philosophies.

Do you see a player who provided great value to a struggling franchise, as evidenced by the rotation-leading 2.81 ERA? Damn the peripherals, what actually happened was good, was mighty, was valuable. In an era of predictive modeling, World Series trophies are still descriptive, after all.

Or do you see a player whose ERA looks like his xFIP cleaned out the fridge, hired a personal trainer, spent half their paycheck on an Equinox membership, and hit the gym twice a day for a few years? A player who, if you look at . . . well, any metric besides ERA, resembles a long-haired, Michelle Pfeiffer-tatted walking red flag?

One of the sneakily exciting storylines of 2019 is the unveiling of the true Dereck Rodríguez. Is he the run-prevention expert we saw a year ago, or a borderline-replacement starter who will never again match his rookie season, as the projections suggest?

Because ultimately, there’s merit in believing either way. Peripherals exist for a reason. History tells us that pitchers who strike out 6.77 batters per nine innings, as Rodríguez did a year ago, rarely fare well. A century-plus of professional baseball data reveals that a 4.56 xFIP likely means that a pitcher will struggle with run prevention going forward.

History also tells us that predictive metrics are infallible, and for that, gentle Giants fan, I refer you to one Matthew Thomas Cain. Cain made not only a career, but carved a spot in every Giants fans’ heart out of suppressing runs better than he was supposed to. His ERA outperformed his FIP and xFIP in nearly every season - often dramatically so. His career K/9 and BABIP numbers are only a few wisps better than Rodríguez’s.

This is not to say that Rodriguez will have a career like Cain’s, or even close. It’s merely to say that if you’re looking for optimism, it’s nearly as easy to find as pessimism.

Rodríguez has already been penciled in as a starter alongside the team’s four veterans. A year ago, that would have been shocking - Rodríguez, early on in spring, winning the one remaining job that Ty Blach, Chris Stratton, Tyler Beede, and Andrew Suarez were all competing for.

And he’s earned that right. He looks good. And I don’t mean that way, though, yeah, okay, I also mean that way.

Rodríguez’s pitches snap. They look as impressive as hitters look uncomfortable when staring at them. He has the composure and demeanor befitting a veteran closer, and seems more than willing to trust his defense rather than live on the margins trying to play the hero. Those things matter, just as his completely unsustainable dinger suppression matters.

It’s worth seeing how well those can play with another season.

We don’t know how well he’ll pitch, but we know that he’ll be a large part of this year’s roster, possibly for better and possibly for worse. In all likelihood, he’ll reside somewhere between the ERA optimism and peripheral pessimism.


G: 26
IP: 158
K: 120
BB: 49
HR: 18
ERA: 3.78
bWAR: 2.4


No, but this one is interesting. The question, of course, is rendered moot if Rodríguez doesn’t perform well. So let’s assume he performs well.

On the one hand, trading a quality pitcher with six years of team control isn’t really what a team should be looking to do in the midst of a quality rebuild. On the other hand, a hot start could give the team an opportunity to sell high on a pitcher who’s about to turn 27 - if Farhan Zaidi believes that Rodriguez’s peripherals will catch up sooner or later, he becomes the type of trade chip that makes a good front office good.

I doubt he’s traded, but the phone calls will definitely be answered.