New Red Sox acquisition Lucas Giolito might be Andrew Bailey's next miracle

Lucas Giolito, the most recent big-name addition for the Boston Red Sox, has seen far better days in professional baseball than he has been through these past few seasons. He seriously struggled in 2022 -- he put up career-worst marks in WAR, K/9 (9.85), fastball velocity (92.7), and Ks since 2018.

Giolito was unable to bounce back in 2023, and finished with a worse WAR and maintained and a ghastly 4.88 ERA. Most notable though, was the amount of home runs he conceded. He was a victim of the long ball 41 times across his 184.1 innings.

There were only two players who gave up more than 40 home runs last season -- Giolito and his former teammate Lance Lynn. They were also in shared company as the only pitchers with 2 HR/9 or greater.

It's a far cry from when he was in the Cy Young conversation in the AL from 2019-2021. And yet, the Red Sox were "one of if not the first team to reach out and show interest."

When I first examined the Giolito signing, I was confused, knowing he had bounced between three teams last season and had not looked as sharp as he once had. But the Red Sox had just hired Andrew Bailey, a coach known for being able to change a pitcher's career after working with them. The most prominent example is Kevin Gausman, who had a career 4.30 ERA before joining Bailey and the Giants in 2020.

How Kevin Gausman's success pertains to Lucas Giolito's with Red Sox

Gausman was not the ace that he is now before he landed on the Giants' pitching staff. Once Gausman had spent a year under Andrew Bailey's tutelage, his BAA (.259 - .229), wOBA (.332 - .283), SLG (.454 - .389), and BB% (7.1% - 6.5%), all saw a decrease, while his K% increased 6.9% from 25.3% to 32.2%.

Gausman has only continued the upward trend from there, finishing this season third in AL Cy Young voting. Now, the Red Sox have Bailey and he has a new project to take on with Giolito.

When comparing Gausman's 2019 season with Lucas Giolito's 2023, some similarities stand out. Their best pitch, according to Run-Value, was their off-speed stuff. For Gausman, his splitter, and with Giolito, his changeup. According to Baseball Savant, both Gausman and Giolito had a below-average fastball and breaking ball, but their other off-speed pitches were above-average. The fastball velocity hovered around 93, 93.1 for Giolito, and 93.9 for Gausman. They both struck out 25% of the batters they faced and struggled to keep the ball on the ground, with Giolito sporting a GB% of 15% and Gausman with 34%.

What made Gausman far more effective in 2020 was making a clear change to his splitter. It saw an increase in velocity (from 83.5 mph to 84.1 mph) and most importantly an increase in spin rate of 134 RPM (from 1583 RPM to 1717 RPM). His increase in spin created an extra inch of downward vertical break and it was a massive difference if you look at Gausman's numbers with the splitter in 2019: BA .231 K% 33. And in 2020: BA .106, K% 46.5.

Giolito's changeup has the same potential as Gausman's splitter. Giolito also relies heavily on his off-speed, so it's a solid pitch for his arsenal. He creates 31.7% CSW (Called Strike + Whiff%) with it and has a .209 BAA when throwing it. His changeup's downward vertical break of 30.7" is in the 90th percentile of all changeups. Similar to Gausman's splitter in 2019, it created a spin rate of 1543. The problem Giolito ran into was that he couldn't prevent the home run ball even with his best pitch. With a FB% of 48.3% -- 20% greater than the league average -- something is amiss.

But most importantly, Giolito has done it before, something Gausman cannot say pre-2020. In 2020, Giolito had a .157 BAA and induced a SwStr% of 24.2%, which was 10% above the league average. The groundwork of an elite pitch is there and Bailey has shown he can unlock that especially with pitchers who are off-speed focused.

He's a serious innings eater, too, with the seventh-most innings pitched in MLB since 2019. Also, his height gives him a big advantage. He's in the 86th percentile in extension among all pitchers. What makes extension so effective is that it can allow pitches to feel like they are coming in at a velocity greater than what they truly are. In Giolito's case, his extension reaches 6.9 feet long, so opposing hitters are facing him at 54 feet as opposed to where the rubber normally lies at 60 feet, six inches.

There's. clear confidence from both Giolito and the organization with this pact. Giolito included a player option after the first year for a reason. He believes in his talent and expects to be worth more than what he is being paid by season's end. There's a foundation of an elite arm and Bailey has shown he can unlock a pitcher's best offering, which is why the Red Sox could see a very good 2024 out of their new right-hander.