The Giants’ Rotation Is One of Baseball’s Unlikeliest Success Stories

Like the rest of us, Aaron Sanchez’s 2020 caught him by surprise. A couple of weeks after a September 2019 anterior capsule surgery on his right shoulder — no easy thing to return from as a pitcher — he was optimistic when speaking with reporters, telling them, “I will pitch next year.” But he was non-tendered by the Houston Astros, and as the winter months came and went, he remained unsigned. Then the pandemic wiped out nearly four months of the 2020 season, and by the time baseball returned, teams weren’t in the mood to pay up for the remaining free agents. It wasn’t until February 21 of this year, 552 days after his most recent pitching appearance, that a team finally signed Sanchez to its big league roster.

That team was the San Francisco Giants, for whom Sanchez made his fifth start on Tuesday and threw 4.2 innings of two-run, one-hit baseball that included five walks and six strikeouts. The lack of certainty surrounding both his health and effectiveness entering the 2021 season seemed destined to make Sanchez an odd fit for the team that took a shot on him, but in San Francisco, his kind is actually right at home. The Giants’ rotation is filled with pitchers who have some kind of major injury in their recent history. In many cases, the return from those injuries hasn’t been graceful; some of those pitchers have found themselves moving to the bullpen in an effort to reclaim some of their value. Many were free agents last winter, with no guarantee they’d be given a starter’s job with their next team. Somehow, the Giants built a rotation out of these guys. And a month into the season, that rotation might be the best in baseball.

Okay, the word “might” is doing some work there. Looking ahead at the team’s next 138 games, you wouldn’t actually project them to out-pitch clubs like the Padres, Dodgers or Mets. But from a pure run prevention standpoint, and looking only at the 24 games they have played this season, San Francisco has been the best. Their 2.17 ERA is tops in baseball, their 3.05 FIP fourth, and five of the six pitchers to start a game this season own an ERA under 2.25.

This is a very San Francisco Giants pitching staff. They strike out hitters at only an average rate, but balance that by doing a good job limiting walks. The starters also rank second in HR/9 (0.64), as spacious Oracle Park has helped to curtail the team’s HR/FB rate (8.9%, second-lowest in the majors) and the pitchers themselves have done their part to keep the ball out of the air in general (51.5% GB rate, the highest in the bigs). Limit free passes, force hitters to put the ball on the ground, and minimize the risk of fly balls clearing the fence, and you’re doing a lot of things that are going to make a pitching staff successful.

How the group as a whole is pulling this off, though, isn’t as interesting to me as the individuals driving that success. A couple of the rows in the above table don’t look out of place. Gausman had an excellent season last year and has generally trended upward since leaving Baltimore after a trade midway through 2018, and Webb is a third-year pitcher whose ERA is finally keeping pace with his solid peripherals. The other four, however, weren’t remotely as easy to predict success for.

DeSclafani, who tossed a three-hit shutout on Monday, has surpassed 130 innings in a season just once since 2016 due to various injuries, and lost his rotation job with the Reds last year when his production fell off a cliff and his ERA ballooned to 7.22 in 33.2 innings. Cueto, meanwhile, made just 13 starts total from 2018-19 because of Tommy John surgery, then got roughed up for a 5.40 ERA in 12 starts last season. Wood was limited to 35.2 innings by a shoulder injury in 2019, then to just 12.2 innings by poor performance with the Dodgers last year. And finally, there is Sanchez, who was last seen working a 5.89 ERA in 131.1 innings in 2019, which followed back-to-back seasons in which he missed large chunks of time due to finger injuries. A comeback season by any one of these pitchers would be an impressive achievement by this team. To have all four pitching this well is unbelievable, especially given the fact that three of them are brand new additions who cost a combined $13 million to sign over the winter.

Any of these starters could be worth a deeper breakdown sometime down the road, but because we’re still looking at just a few appearances by each one, I’ll stick to briefly explaining what’s made each successful early on, and what makes them compelling to follow in the near future. I’ll start with Sanchez. If you’ve followed his career to this point, you probably remember him for breaking into the majors with two very hard fastballs that both averaged well over 97 mph. Over time, that velocity gradually dipped, to around 95 mph in 2016 and then around 93 mph in 2018-19.

This year, in his first action since his surgery, his fastball is averaging less than 90 mph. Now, that sounds really bad, but it might not actually be as detrimental to him as you’d think. Keep in mind, even when Sanchez threw really hard, he wasn’t very good at getting whiffs — his career strikeout rate is only 18.6%, and it’s topped 20% only once since his rookie year. In other words, he always had the strikeout proficiency of a guy throwing 90 mph. Now that he actually is throwing that velocity, you might expect the strikeouts to have tanked further. But you’d be wrong.

Sanchez’s strikeouts haven’t dropped off with the decrease in velocity, but even better, his walks have. Before he walked five Rockies in 4.2 innings on Tuesday, he had walked just four batters in his first 19.2 innings of the season. That gave him a walk rate of just 5%, and while we can’t just discount his most recent start, his first four games are a very encouraging step for someone who was walked nearly 12% of the hitters he faced from 2017-19. Combine that with a 60.3% groundball rate — his best since 2015 — and you can start to see a version of Sanchez that has a real chance to succeed, in spite of his diminished stuff.

The story is similar for Wood, another pitcher who has had to work his way back from serious shoulder issues. With just two starts under his belt, the southpaw boasts the smallest sample size in this group, but also some of the best results — his xwOBA is in the 94th percentile, as is his xERA. Like Sanchez, Wood has found success early on by cutting down on walks and dramatically improving his groundball rate. Unlike Sanchez, though, Wood hasn’t compromised on velocity to do so. His average sinker is registering 91.4 mph this season, his best figure since 2017. He’s thrown that in tandem with a slider he just began throwing in 2020, but which has shown incredibly promising results so far. Opponents are chasing the slider at 48.3% rate, and are missing it on 47.4% of their swings.

The slider replaced Wood’s curveball, which he’d thrown as his only breaking pitch since he reached the majors in 2013. The curve was a good weapon for Wood until 2019, when it was suddenly his worst offering during an injury-scarred season in Cincinnati. It allowed the highest wOBA of any of his pitches that year, and its whiff rate fell to its lowest point ever. The following season, it was scrapped, and the emphasis Wood has placed in the slider shows how much he trusts it. After never throwing his curveball more than 30.7% of the time in any given year, he’s thrown sliders on 39.2% of his pitches so far in 2021. Again, we’re talking about just two starts here — both of which came against the Marlins — but the new arsenal is worth keeping an eye on going forward.

The sample for Cueto, currently on the Injured List with a Grade 1 lat strain but expected back in the second week of May, isn’t much bigger than Wood’s but has been impressive nonetheless. Through three starts, Cueto has his best strikeout rate since 2014, his lowest walk rate since ’16, and his highest whiff rate ever. The whiff rates against his four-seamer, slider and sinker are all up at least 11 points from last season, despite the fact that he’s throwing a career-high rate of strikes.

There are reasons for caution, of course. Cueto’s not having allowed a home run through three games gets a bit more suspicious once you know his groundball rate is currently at a career low, and his hard hit rate is up nearly nine points from his career average. But we are talking about someone who spent much of his career in Cincinnati maintaining a well below-average HR/FB% despite pitching in a bandbox, and at 35 years old, his average fastball velocity is actually the highest it’s been in five years. Baseball is just more fun when Cueto is pitching well, especially when it looks like this:

Somehow, Cueto isn’t the last former Reds pitcher we have to talk about. I already mentioned the complete game shutout DeSclafani threw on Monday, but what I didn’t mention was that three of his previous four starts with the Giants also resulted in one run allowed or fewer. After 30 innings, he ranks fourth among qualified pitchers in ERA, and 14th in FIP. When he was healthy in Cincinnati, DeSclafani was capable of putting together impressive hot streaks, and this one ranks up there with some of his best.

At the time he signed, DeSclafani seemed like a good fit for the Giants as a fly ball pitcher hoping to find an accommodating home. So far, consider that part of the mission accomplished — DeSclafani is allowing a HR/FB rate of just 8%, down from 16.3% over his final four years in Cincinnati. But that’s not all there is to this. At the risk of sounding like a broken record, DeSclafani has also dramatically increased the number of strikes he’s throwing, the number of groundballs he’s inducing, and the number of whiffs he’s compiling.

Every team enters the offseason with room on the fringes of its pitching staff to take a flier on a bounce-back candidate. The Giants went several steps beyond that, practically constructing an entire rotation out of them. The odds that they all continue to throw like Cy Young candidates for the entire season are next to nothing, but again, I’m not here to decide exactly how good the Giants’ pitching staff is. We can’t know that for a little while longer. All we know now is that they’ve pitched like baseball’s best rotation for a month, and there hasn’t been a lot of smoke and mirrors to it, either. Considering where many of these pitchers are coming from, and what their expectations were coming into the season, that’s nothing short of astonishing.