LAKE BUENA VISTA, Fla. -- Over the years, the Rays earned a reputation as one of the best places in baseball for pitchers to go and get better. It’s played out again and again: a talented arm plateaus elsewhere for whatever reason, arrives in Tampa Bay, and revives his career or blossoms into a breakout star. 

Is Zach Eflin that next guy?

The Rays essentially bet $40 million this offseason that the veteran sinkerballer is that pitcher. And while the Orlando native’s full-circle journey has provided a feel-good storyline for his first few days in camp, there is a baseball side that certainly factored more into the Rays deciding to make Eflin the richest free agent acquisition in franchise history. 

Few teams evaluate their pitchers better than the Rays, and few teams are better at unlocking upside that talented guys might not have realized elsewhere. They clearly see something in Eflin. 

“He’s a guy that we’d like to think is on the verge of really doing some special things,” manager Kevin Cash said.

Here are a few reasons why:

The underlying numbers

Though highly-touted going back to his days as a prepster, Eflin performed like a roughly Major League-average starter over parts of seven seasons with the Phillies, going 36-45 with a 4.49 ERA (95 ERA+). His results were almost exactly MLB-average in 2022 (101 ERA+), before transitioning into an effective relief weapon for Philadelphia’s postseason run. His sinker-heavy arsenal doesn’t miss bats at a high clip, and he’s battled through recurring knee injuries.

But those numbers don’t tell the whole story. Looking under the hood, Eflin’s peripherals suggest there might be an elite pitcher in there waiting to be unleashed (all 2022 rankings):

• Avg. exit velocity: 96th percentile

• Hard-hit percentage: 94th percentile

• Walk rate: 91st percentile

• Extension: 83rd percentile

• Expected ERA: 75th percentile

Eflin is able to produce so much weak contact because his pitches move a lot. His sinker, four-seam fastball and curve -- which emerged as his primary out-pitch last year -- all rate very well in terms of horizontal movement.

“Hopefully,” Cash said, “he just continues to get better.”

The command

“In an era of power and velocity, he’s an artist,” Rays president of baseball operations Erik Neander said of Eflin in the offseason. Art is subjective, but Eflin is definitely stingy -- and he seems to be getting better at limiting free bases.

Walk rate, by year:

• 2019: 6.8 percent (2.6 BB/9)

• 2020: 6.1 percent (2.3 BB/9)

• 2021: 3.6 percent (1.4 BB/9)

• 2022: 4.8 percent (1.8 BB/9)

“I love that trait about myself,” Eflin said. “I love challenging hitters. I love seeing what guys can do and what I can do against them. Walking is kind of giving in, caving, in my mind. I understand pitching around certain guys in certain situations. But I believe the day I start walking people is the day I'll probably retire.”

If nothing else, that baseline skillset was attractive to a Rays rotation that lost one of the game’s top strike-throwers, Corey Kluber, to free agency.

The team they can put around him

Being a contact-heavy pitcher in a hitter-friendly home ballpark, Eflin long underperformed his underlying metrics, and especially as he’s matured as a pitcher over the past three years. Since 2020, Eflin’s ERA (4.08) is more than a full half-run higher than his FIP (3.57) across 240 1/3 innings. His .321 opponent average in that time is likely skewed by some luck and Philadelphia's defensive issues behind him; the Phillies ranked as the Majors’ second-worst defensive team (-73 outs above average) in that span. The Rays ranked as MLB’s eighth-best (fourth in the American League).

While the Rays’ infield defense did slump in 2022, that was at least partially attributed to the injuries that forced key infielders Wander Franco and Brandon Lowe off the field for long stretches. The club sees real potential for year-to-year improvement there, with both back healthy this spring.

The benefits Eflin should receive on balls in the air seem even easier to predict. The Rays have had baseball’s best defensive outfield since 2020 (64 OAA), and had the AL’s best last year, while the Phillies ranked as the MLB’s second-worst both in ’22 and over the past three seasons. Eflin should also get a boost making his home starts at Tropicana Field (5th-most pitcher-friendly park, per Statcast), compared to hitter-friendly Citizens Bank Park (fifth-most offense-friendly).

"I don't think we're asking Zach to do anything different than be the guy he's been,” Cash said. “We have a very strong group of pitchers that we can put around them. And they can all complement each other.”