With a Cy Young Award and World Series ring in his collection, Arrieta owns two pieces of shiny hardware that Darvish doesn't. Arrieta also has the distinction of never having had Tommy John surgery. Despite that, he has only 1,669 professional innings on his arm to Darvish's 2,127.2.
However, Arrieta doesn't have all the advantages.
He has one All-Star nod to Darvish's four. And while both are 31 years old, Arrieta is Darvish's senior by 163 days. Courtesy of the trade that sent him from the Texas Rangers to the Los Angeles Dodgers last July, Darvish also has the advantage of having been barred from a qualifying offer and is thus spared from ties to draft-pick compensation.
So to determine which of them is more worthy of a big-money contract, a deeper dive into their pasts, presents and futures is warranted.
Where They've Been
Darvish was only 18 when he began his pro career with the Nippon Ham Fighters of Japan's Nippon Professional Baseball back in 2005. Seven years later, he was the proud owner of a sparkling 1.99 ERA over 1,268.1 NPB innings.
That begat a $107.7 million investment—a $51.7 million posting fee plus a $56 million contract—from the Rangers to bring Darvish to MLB in 2012. The right-hander flourished as a rookie with a 3.90 ERA in 191.1 innings and achieved a career peak with a 2.83 ERA in 209.2 innings in 2013.
Since then, Darvish has experienced his share of highs and lows.
Injuries limited him to 22 starts in 2014 before he missed the entire 2015 season after undergoing Tommy John surgery. Knowing that, it's understandable if teams have misgivings about handing over a nine-figure deal to a pitcher whose elbow has already been surgically repaired.
But for these clubs, it's worth some comfort that Darvish hasn't missed many beats over the last two seasons.
He returned in 2016 to post a 3.41 ERA in 100.1 innings. Then came a 3.86 ERA in 186.2 innings last year. Along the way, he's struck out 10.7 batters per nine innings while walking 2.8 batters per nine innings.
* Per Baseball Reference, minimum 800 IP between 2012 and 2017.
Arrieta's career has humbler beginnings. He was a Baltimore Orioles fifth-round pick in 2007, reached the majors as a 24-year-old in 2010 and then struggled to get off the ground with a 5.46 ERA across parts of four seasons.
The Orioles effectively gave up on him in 2013, sending him to the Chicago Cubs in an early-July trade centered on Scott Feldman. Fast-forward four-and-a-half years, and there's Arrieta standing at the end of the 2017 season with a 2.73 ERA as a Cub.
Arrieta already had a great arm, but the Cubs changed how and what he threw. They raised his arm slot and moved him to the third base side of the rubber. They also freed his slutter, a cutter/slider hybrid that had been sort of a pitch non grata in Baltimore.
"When I go away to righties, when I try and elevate it and I want to expand it off the plate, it's more of a cutter," Arrieta told Jorge L. Ortiz of USA Today in 2015. "If I want to use it underneath a lefty's swing or in the dirt for a chase pitch to a righty, I'll use more of a slider, take some velocity off it slightly and increase the break of it."
Arrieta achieved his peak in 2015, and what a peak it was. He put up a 1.77 ERA in 229 innings overall and finished the year with a microscopic 0.86 ERA over his final 20 starts. Included within was a dominant no-hitter against the Dodgers in August.
Alas, the only way to go after a season like that is down.
Arrieta regressed with a 3.10 ERA across 197.1 innings in 2016 and fell further with a 3.53 ERA across 168.1 innings in 2017. He's holding steady as an above-average K/9 artist, but his BB/9 rate and HR/9 rate have settled around average.
Where They're Going
The extreme upside Arrieta displayed in 2015 was no fluke.
He pitched off a fastball that sat at a career-best 94.6 mph. And since he prefers a sinker to a four-seamer, batters also had movement to contend with. He also didn't skimp on movement with his slutter or curveball, yet he nonetheless kept his location on point.
Well-rounded dominance resulted. He walked only 1.9 batters per nine innings. When batters did swing, he held them to an excellent 76.3 contact percentage. When hitters made contact, he limited them to an MLB-best 84.0 mph in exit velocity.
The trouble is, there's a fair deal of distance between the guy Arrieta was then and the guy he is now.
His 2017 fastball averaged only 92.1 mph, 2.5 ticks below where he was in 2015. He's also been weaning himself off his slutter, as he threw it only 14.2 percent of the time in 2017. These things help explain why his contact rate shot above the league average, as well as why his exit velocity climbed to 87.2 mph.
In Arrieta's defense, none of this got in the way of his being an above-average starter. But any team that signs him will be hoping for something more like the 2015 version of Arrieta. That's a lot to ask.
Mind you, Darvish has his own red flags.
Although he used his trusty slider for 25 percent of his pitches in 2017, its whiff rate fell to a career-worst 14.5 percent. It's still pretty to look at, but that doesn't erase concerns over whether it's past its prime as his go-to out pitch.
Teams also can't be enthused about Darvish's track record as a big-game pitcher.
He got only one more out (10) than he gave up runs (9) in his two World Series starts for the Dodgers against the Houston Astros. Altogether, he owns a 5.81 ERA in 26.1 postseason innings. Despite issues of his own—including 16 walks in his last four outings—Arrieta owns a comparatively better 3.08 ERA in 52.2 postseason innings.
What can be said in Darvish's defense, though, is that there was weird stuff going on in the World Series.
It was alleged that slicker balls were making it tough for all pitchers to throw good sliders. On top of that, one Astros player told Tom Verducci of Sports Illustrated that Darvish was tipping his pitches.
Furthering Darvish's defense, his arm appears to be in tip-top shape.
He returned in 2016 with a career-best 93.3 mph fastball, only to beat that mark with a 94.2 mph fastball in 2017. He's also maintaining a deep arsenal. He featured a four-seamer, sinker, slider and curveball in 2017, plus a few changeups and splitters on the side.
Even if his slider is losing something, what he has is more than enough to keep getting by just fine. To wit, his contact rate is staying safely below the league average, and he finished 2017 having allowed just 85.7 mph in exit velocity.
Survey Says: Darvish
To be clear, there's been plenty of interest in both these pitchers throughout the winter.
According to Jeff Wilson of the Star-Telegram, Darvish is said to be weighing returns to either the Rangers or Dodgers. He's also considering the Cubs, New York Yankees and Minnesota Twins.
Arrieta could still return to Chicago. The Milwaukee Brewers also have interest, according to Jim Bowden of The Athletic. Others have speculated the St. Louis Cardinals, Philadelphia Phillies and Washington Nationals could be fits.
Of course, either hurler will require teams to invest significant money in a significant risk. They're both older pitchers, after all. The breed isn't known for reliability.
But between the two, Darvish takes the proverbial cake.
It would be a different story if Arrieta were still functioning like the otherworldly ace he was in 2015. But by all accounts, he isn't the same pitcher anymore.
Even if Darvish doesn't have any upside left, the pitcher he is now is roughly equivalent to the pitcher he's always been. Maybe his slider isn't the same, but he still boasts great stuff and improved control.
True, he'll likely cost more money than Arrieta. But it's a fair trade-off that he won't require a team to lose one or more draft picks.
Either way, let's end with a plea for all pitching-needy teams out there: Would somebody please sign these guys already?