For years, it seemed no amount of pitching injuries could topple the Tampa Bay Rays; whenever one man went down, they had someone waiting in the wings to take his place and get the job done. Often, a virtual unknown, at that.

For their American League East rivals in Boston, it defied logic and evoked a lot of envy. The Red Sox’s struggle to develop homegrown arms predates the Rays’ very inception in 1998, and many of the Sox superstars who pitched the club to their four championships this century were brought in via trade or enormous contract: Pedro Martinez, Josh Beckett, David Price, Rick Porcello, Craig Kimbrel, Chris Sale.

Over the last half-decade, in particular, Boston watched helplessly as their pitching staffs fell apart. Year after year, promising seasons plummeted down the drain because the organization didn’t have enough depth to sustain mounting pitching injuries. So when Lucas Giolito’s season ended a week into spring training games, evaluators declared the pitching staff sunk before its maiden voyage.

Instead, the Red Sox entered Monday with a respectable 21-19 record and in third place in the division, a game and half ahead of the Rays.

What a difference pitching makes. “I think today coming into the series, I was like, ‘Finally we’re pitching better than others,’ and we haven’t done that in a while,” Alex Cora said Monday afternoon.

The pitching staff entered Monday leading the Majors with a 2.75 ERA, the club’s best mark through 40 games since the Live-Ball Era began in 1920. The Sox are currently the only team with a sub-3.00 ERA, according to the club’s media relations, they’re only the 15th team to record an ERA that low through their first 40 games. They’ve pitched an MLB-leading six shutouts, already one more than they compiled all last season.

The starting rotation leads the Majors with a 2.45 ERA, also the franchise’s best mark in the Live-Ball Era, and the fifth-best mark through 40 games by any team this century. (The 2019 Rays narrowly edged them with a 2.44 ERA.) Sox starters also rank third in WHIP (1.05) and opponent average (.217).

Ask any Sox pitcher to talk about their improvement this year, and the answer is immediate and identical: Andrew Bailey.

The former Sox reliever and their new pitching coach, known affectionately as “Bails,” is heading up a transformed pitching development unit. As the above stats indicate, the results thus far are not only promising, but historic, even if Bailey is too modest to take the credit players are constantly giving him.

“The guys are throwing the ball really well,” the pitching coach told the Herald proudly before Monday’s series opener. “Lot of baseball games to play, but we’ve been able to withstand some injuries. The guys that we’ve brought up have done amazingly well at fitting right in and sticking to their plans, asking the right questions, so I couldn’t be more proud of the work that the group’s putting in.”

“The right questions” for Bailey don’t necessarily have “right answers.” Baseball is, after all, somewhat mysterious, impossible, and unknowable.

“It’s a game, so generally, players are curious, they want to have success, they want to know if it’s sustainable,” he explained. “And sometimes there’s ebbs and flows, and we have to adjust, but when we understand and players understand what they do really well and sets them apart from the group, and kind of their outlier characteristics as a pitcher, they can relentlessly attack the zone with their strengths. That’s what we want them to do.”

Bailey and Co. went into this year well aware of the club’s pitching reputation, and motivated to shock the competition.

“Our goal at the onset of the season was, we want teams to come in here or us to go to an opposing stadium and have them know, we’re gonna come at you with our best stuff,” he said. “We want to be viewed within the industry as such, and so far the guys have done an amazing job.”

Among the standouts is a newcomer whose signing early in the offseason barely made a ripple.

“I didn’t know him personally at all,” Bailey said of Cooper Criswell. “But he’s awesome, just kind of a carefree guy. He’s very curious, very focused, understands what he needs to do, funny, really good fabric-of-the-clubhouse, and that’s the kind of person we want, just good people. He fits that mold.”

He’s also dominated since the Red Sox called him up from Triple-A. Over six games (five starts) for Boston, Criswell the 27-year-old righty owns a 2.10 ERA across 25.2 innings. Over his five starts, it’s a 1.93 ERA, the third-best mark on the staff before the series began, and no more than two earned runs allowed in any outing. The Red Sox are 5-0 when he starts, a feat they hadn’t accomplished for a pitcher since Nick Pivetta (2020-21), and John Burkett (2002).

“Coop’s been awesome,” his coach said. “He’s been super open since Day 1 in the offseason when we signed him. Extremely hard-worker and coming into camp, was open-minded with roles, versatility, usages, his arsenal in general. And then to go out and have success and continue to dominate lineups has been awesome to watch. Really, just watching him compete has been so much fun.”

Start No. 6 will be a bit different, though ideally with results along the lines of his first five. Criswell is scheduled to start Thursday’s series finale against the team that claimed him off waivers in July ’22, then designated him for assignment last November. He made one start for them that first season, and 10 relief appearances in the second; over 36.1 innings in a Rays uniform, he allowed 22 earned runs (24 total).

In other words, he’s not the same Cooper Criswell the Rays DFA’ed.

“For sure, I mean, it’s exciting,” the righty said. “I feel like you don’t want to look too far into it as far as it’s just another game. Go out there with the same game plan we’ve had the last five starts. Attack the strike zone with all four of my pitches, try to keep everyone off balance, but for sure, a little extra excitement going into it knowing it’s my former team. For sure looking forward to it.”

“I think any time you play against a team that you were a part of, there’s always a little bit of uneasiness or extra motivation,” Bailey agreed. “He’ll be competing. I expect him to be going out and performing as he has so far.”

Criswell is more than happy to spread the gospel of Bailey.

“Tampa Bay, great pitching staff over there, always have great years pitching,” the righty said, “but I really, I feel like all this goes back to getting Bailey over here and getting his plan in, and really attacking his plan, everyone buying in.”

“With Bailey here, everyone’s buying in. Love his philosophy. The catchers, everyone, in general’s, on the same page,” Criswell explained. “Throw your best stuff in the zone. It’s the baseball norm to throw your fastball the most, but if it’s not your best pitch – we’re throwing our best pitches whether it’s off-speed or not. In those counts, hitter’s counts, we’re still attacking with our best stuff whether it’s off-speed or fastball. Really, just buying into that.”

“It sounds simple, everyone wants to go out there and do that,” he said of Bailey’s mantra: throw your best stuff.

The execution is, of course, far more difficult, but Criswell and his fellow pitchers are thriving because their coach is helping them be the best versions of themselves, not trying to transform them into something else. So far, the results speak for themselves.

Criswell is eager to see where Bailey’s road leads the Red Sox.

“Hopefully, for the years to come, everyone’s talking about the pitching staff the way the Rays have been talked about in years’ past,” he said with a smile.