Kirby is the son of former Florida International University baseball player George Sr. and his wife Linda.

In 2016, George graduated from Rye High School in New York.

In 2016, the Mets chose him in the 32nd round, but George chose a baseball scholarship to Elon University. 

In the summer of 2018, Kirby used a spot in the Cape Cod League to add to his profile. While successful with Harwich with 28 strikeouts in 15 innings (giving up two runs), it gave him an idea of what he needed to work on.

“I had to use all my pitches this summer. The changeup was working very well,” George said. “It was a good experience because it’s something I need to get used to, just being able to pitch against all those guys.”

Kirby has the desire to be really good. And he has the tools and work ethic for that to work out.

In 2019, pitching for Elon, Kirby struck out nearly 18 batters for every walk he issued as a college junior. He totaled 107 strikeouts and six walks in 88.1 innings. What’s so ridiculous about that was no other pitcher, at any NCAA level, was even close to Kirby's strikeout-to-walk ratio.

"It kind of punches you in the face when you look at it,” scouting director Scott Hunter said. "You have to ask if it’s real.”

In other words, is Kirby's strike-zone dominance a fun bar trivia stat, or is his approach truly transferable to pro ball?

"With all the technology and all the analysis and video stuff we have, it is,” Hunter said. "I don’t think there’s anybody in the country who has sniffed his strikeout-to-walk rate and it’s something we really value here.”

While some scouts will critique the level of competition that Kirby faced in the Colonial Athletic Association and don’t expect him to miss many bats against better competition, it’s impossible to ignore his strike-throwing ability. There’s also his impressive 2018 in the Cape Cod League, where Kirby worked as a reliever and posted a 1.38 ERA over 13 innings, striking out 24 and walking only one. (BA - June 2019)

June 2019: The Mariners chose Kirby in the first round (#20 overall), out of Elon University in Elon, NC. Kirby agreed to a $3,242,900 signing bonus, via scout Ty Holub.

Kirby is the first player ever selected in the first round out of Elon, a private liberal arts university with an enrollment of about 6,700, which competes in the Colonial Athletic Association.

2019 Season: Kirby made a name for himself as a control artist at Elon University and parlayed that into being a first-round pick last June. 

George spent 2020 at the Mariners’ alternate training site remaking his body to add velocity and power to his arsenal.

In 2021, the Baseball America Prospect Handbook rated George as the 7th-best prospect in the Mariners organization. But he moved up to #2, early in 2022.

2021 Season: Kirby finished the year with a 2.76 ERA, tossing 62 innings over 14 starts and striking out 74 batters while allowing 14 walks. In 2022, the 23-year-old is expected to follow Logan Gilbert as the next young Mariners starter to make an impact in Seattle.

Feb 17, 2022: Mariners best prospect drafted out of college – George Kirby, RHP (No. 3, MLB No. 33)

The second of three straight college right-handers taken by the Mariners in the first round, Kirby became the first-ever first-rounder from Elon University in 2019. He entered pro ball known as an extreme strike-thrower, thanks to his 1.9 BB/9 rate in his three years at Elon (to go along with a 9.7 K/9 rate and 3.30 ERA). And he rose into the first round thanks to his 10.9 K/9 rate and 0.6 BB/9 rate in his Draft year.

Striking out 25 and walking none in 23 IP during his pro debut did nothing to hurt his rep. And all he’s done since is throw much harder while still filling up the zone (2.0 BB/9 in 2021).

March 3, 2022: Those who intently read scouting reports and prospect rankings by now know all about George Kirby’s velocity spike into the high-90s, the deceiving arm speed that he sells his off-speed pitches with and, of course, the pinpoint command that has yielded among the lowest walk rates in the Minors.

Yet he hasn’t always possessed that precision. In fact, his biggest pitching weapon in youth was an all-over-the-place offering that has slowly receded from the pro ranks: the knuckleball.

“It wasn't commanding in the strike zone well, but people were swinging and missing because I threw hard at that age and no one had ever seen a knuckleball before,” Kirby said at the Mariners’ Spring Training facility, where the Minor Leaguers opened camp.

No, he doesn’t use the knuckler in-game anymore . . . but that doesn’t mean he couldn’t if he wanted to.

“Absolutely,” Kirby said. “It’s nasty.”  The confidence with which Kirby spoke of his favorite pitch of yesteryear was emblematic of his approach to the 2022 season. Seattle’s No. 3 prospect and baseball’s No. 33 overall, Kirby has checked every player development box since being taken with the No. 20 overall pick in the 2019 Draft. And he is widely viewed as one of the more advanced pitching prospects in the game.

A “quiet assassin” of sorts, as referred to by scouts and teammates, Kirby embodies that persona well beyond the mound.

“I've never been scared to face anyone older than me,” Kirby said. “My plan is always just attacking the zone and seeing if they can beat me. I've been doing that for years and it's working out pretty good.”

“When you're talking to George right here, he's laid back, chill, really relaxed,” said fellow pitching prospect Isaiah Campbell. “But that's the golf course; when he gets on the mound, he's a competitor—a different animal.” 

Kirby is coming off a 2021 in which he climbed from High-A Everett to Double-A Arkansas at midseason and reached 67 2/3 innings over 15 starts, an accumulation that would’ve been higher had he not experienced right shoulder fatigue in July. Yet when healthy, Kirby continued to wow, compiling a 2.53 ERA and striking out 80 for a 29.1% rate. His walk numbers remained among the best in the Minors; just 15 to 274 batters (5.5%).

What the Mariners have been most impressed with is Kirby’s ability to maintain his elite command while experiencing a significant increase in velocity. When the club drafted him out of college, Kirby was sitting at 92-93 mph and topping out at 95. In 2021, he averaged 96 mph and was touching 100.

“I think just the older I get, I throw a little harder,” Kirby said. “I definitely put a lot of work in my body just trying to get really healthy. The velo has come and it hasn't hindered my ability to throw strikes either, which is a great feeling.”

He complements the heater with a curveball and a slider, both plus pitches, and a changeup that he’s deliberately turning to more this spring. All of them are lighting up green on the Mariners’ pitch-tracking tools.

“It’s going to be a big weapon for me this year,” Kirby said of his changeup. “I've been just trying to throw it as much as I can; catch play, throw in all different kinds of counts during bullpens and live BP, so it's just been feeling really good. I’m trying to look for 2:30, 3 o’clock spin direction, something that just dives off the plate, and I think I did a pretty good job of that. I’ve just got to make it believable in the zone first, and that way, I'll get a lot more whiffs on it.”

Kirby will be the headliner of the next wave of talent in the Mariners’ pitching-heavy farm system, which was most recently ranked No. 2 in baseball, per MLB Pipeline. The club won’t rule out his shot at the Opening Day rotation, but it seems more likely that it won’t throw him in the ringer right away. 

Kirby has never thrown more than the 90 1/3 innings during his sophomore year at Elon in 2018, but a leap to the 120-130 range could be a realistic target for 2022. Yet delicately managing those while keeping Kirby on the mound deep into September will be the most vital component to his player plan. Because the Mariners intend to compete for the postseason this year . . . and they plan on Kirby being a big part of it. (D Kramer - MLB.com - March 3, 2022)

MLB debut (May 8, 2022): When Mariners starter George Kirby walked back to the dugout after an electric first inning, fans at T-Mobile Park were on their feet.

Kirby, the club’s top pitching prospect, struck out the first batter he faced in his big league debut against the Rays. Then, after allowing a quick base hit, he answered with back-to-back strikeouts to end the inning, returning to the dugout as cheers echoed across the ballpark. That energy never let up.

Kirby was brilliant in his debut on a chilly, but sunny afternoon in Seattle, completing six scoreless innings, and allowing four hits while striking out seven on 81 pitches. “It’s great,” Kirby said. “For myself, and then just the guys believing in me, too, to go out there and do my job on the mound — I’m just happy.”

Even when the 24-year-old’s day was complete, a “George Kirby” chant broke out from a group of fans behind home plate. Kirby’s parents and sisters, as well as more family and friends, were in attendance to share in the moment. That group included a cheering section of 15-20 friends from his playing days at Rye High School in New York and Elon University in North Carolina.  (Lauren Smith)

Kirby has a 94-100 mph FASTBALL and tops out at 102 mph with explosive late life up in the zone. He generates his velocity with little effort and locates his fastball to both sides of the plate with plus-plus command, making it a swing-and-miss pitch even when batters are geared up for it.

His heater is a 70 grade because of his ability to elevate it when necessary. He has a 79-80 mph downer CURVEBALL that is 55 grade. He improved an 85-87 mph SLIDER. It is an above-average 60 grade pitch with depth and a sweepy break. The curve and slider tend to blend into a slurve, on occasion. He has an impressive 84-86 mph fading CHANGEUP, which he throws with conviction and consistently lands in the bottom of the strike zone and is a 50 grade.

Kirby appeals to evaluators of all types, thanks to the quality of stuff and the ease with which he does it, blowing up all metrics like velocity, movement, command, swing and miss, and lack of hard contact. He can now run his fastball up to 100 mph, turning what was a low-90s heater into one that sits in the upper-90s range consistently. He has two distinct breaking pitches, both of which are plus at times, and he sinks a solid changeup as well.

The velocity gains have done nothing to hamper Kirby’s ability to drop the ball on a dime, as the right-hander walked just 2.0 per nine in 2021. The only thing that’s holding him back is experience, and he did miss some time with shoulder fatigue, but he’s looking more and more like a frontline starter. (Spring 2022)

George is a good athlete with excellent body coordination and repeats his delivery for elite control. He has averaged 1.5 walks per nine innings in his minor league career and his misses are very small. Kirby’s rare mix of power and precision gives him the potential to be a No. 1 or 2 starter as long as he stays healthy. (Kyle Glaser - BA Prospect Handbook - Spring, 2022)

George has earned plus or better grades on his fastball, changeup and slider, and just a tick lower on his curveball.

In 2021, he won the Best Pitching Prospect, Best Fastball and Best Control categories in the High-A West, making him the only pitcher this season to win three categories in one league. (Baseball America - Sept., 2021)

George was one of the prospects invited to the Mariners’ alternate site in Tacoma in 2020, and his progress began to show in big ways during the following spring training in 2021. That’s when he unveiled a fastball that had jumped way, way up, all the way to 102 mph.

“It felt great,” Kirby said of his uptick in velo. “When that happens, your arm just feels so good. Everything comes out nice and easy, you’re not really trying to overthrow, and it just comes out.”

Beyond his velocity spike, Kirby’s changeup also made impressive strides. Scouts liked it as his best secondary pitch as an amateur, but a change in the way he throws the pitch—based on analytical feedback—has turned it into an even more potent weapon.

The sheer separation in velocity between his fastball and changeup, which is usually around 10 mph, is excellent enough. But now a tweak in the way Kirby grips the pitch has created a version with deeper break.

“Just the idea of having a 10 mile per hour difference is meaningful,” Mariners pitching coordinator Max Weiner said. “When he’s able to do that and then move the ball toward the outer part of his hand, (while) being driven by the pinkie and ring finger, he’s able to generate meaningful side spin. So he’s pushing the ball to the side, which is creating the depth and less horsepower behind the pitch and giving him the velocity separation.”

Kirby’s breaking pitches have come forward, too. His slider has added more sweeping break, and the depth of his curveball gives him another pitch with vertical movement. Combined, Kirby’s arsenal gives him pitches he can use to all quadrants of the strike zone.

“It’s tough, and I think it’s unique because it could change day by day,” Everett manager Louis Boyd said. “There are times when his curveball just seems unhittable, and then his slider will have an insane amount of sweep to it. And now he’s throwing changeups to righthanded hitters. It’s got to be tough as a hitter to not know what his out pitch is, because he’s got four of them. When he locates the fastball at the top of the zone, it doesn’t need to be the off-speed to be an out pitch, so it’s pretty special.”

The most impressive part, however, is that none of the added stuff has come at the expense of his signature command and control.

“To George’s credit, he really evolved, and I think he would say the same thing,” Weiner said. “He’s really evolved his approach from bulk strikes into really quality, strategic strikes, where he’s going to really safe spots in the zone and around the zone.

“That means that instead of moving pitches around for the sake of moving them around, he’s really being intentional about targeting locations where he has extra room to miss, and he’s giving himself margin for error. And I don’t think it takes too long to watch him to realize he doesn’t need all that room. When that skill set and that approach converges on a singular point like that, the results are pretty exciting.”

So when word began to get around in spring 2021 about just how much Kirby’s stuff had jumped—without any sacrifice in control or command—the industry quickly had another name to add to the list of high-end prospects in a system that entered the year ranked only behind the Rays. Multiple evaluators from rival teams have pegged Kirby as a top-of-the-rotation starter, thanks to his combination of athleticism, stuff, and command.

“His stuff is explosive, and beats hitters at the top of the zone,” one scout said. “I have him at the top of the rotation with a unique power and precision package.” (Josh Norris - Baseball America - Aug 2021)

While Kirby is known more for his command than anything else, he has more than enough raw stuff at his disposal. He delivers a four-pitch mix from a 6-foot-4 frame, starting with a fastball with good running life. He’s worked on adding strength which will lead to more consistent velocity as well. Kirby throws both a curve and a slider, with the former slightly ahead, and both have the chance to be out pitches. He does a nice job of selling his sinking changeup with excellent arm speed.

All of Kirby’s stuff plays up because of his command, which might be as good as any pitcher in the Minor Leagues. He walked virtually no one during his last season at Elon. And then walked literally no one over 23 innings of his pro debut in 2019. His combination of improving stuff and elite-level control all point to him moving very quickly up the organizational ladder. (Spring 2021)

George has 70 grade Control. Now he has to show he can maintain his velocity uptick over the course of a full season in a competitive environment. If he can, he’ll be a potential mid-rotation starter or better. (Bill Mitchell - Baseball America Prospect Handbook - Spring, 2021)

The 6-foot-4 Kirby has four pitches that all have the chance to be at least above-average when all is said and done. It starts with his fastball with good running life. As Kirby adds strength, there could be more consistent velocity, similar to how Gilbert has developed. Kirby has two distinct breaking balls, with his curve slightly ahead of his slider now, but both show flashes of being potentially plus. He has feel for his sinking changeup as well.

To call Kirby a strike-thrower would be an understatement. As a junior at Elon, he led all Division I pitchers in strikeout/walk ratio (17.8) and walk rate (0.6 per nine innings). Then he didn't walk a single batter in 23 innings during his pro debut. He was very fastball-reliant in college and will have to continue to refine his secondary stuff, but he has all the makings of a mid-rotation starter who can get to Seattle in a hurry. 

Where Kirby stands out most is his plus-plus control. He has a clean arm action and plus command, allowing him to put the ball wherever he wants in the strike zone. (Spring, 2020)

George is an elite strike throwers—one of the best in the game! While there are pitchers with louder pure stuff than the 6-foot-4, 201-pound righthander, Kirby is among the most likely 2019 draft prospects to make a Major League impact because of his clean arm action and plus command.

Kirby looks the part of a solid, middle-of-the-rotation or back-of-the-rotation starter.

In 2019, George racked up 107 strikeouts and just 6 walks in 88 1/3 innings at Elon. He led all NCAA Division I pitchers with a stunning 17.8 strikeout-to-walk ratio and the fewest walks per nine innings at just .611. 

“It kind of punches you in the face when you look at it,” Mariners scouting director Scott Hunter said of Kirby’s numbers. “You actually have to ask if it’s real. With all our technology and analysis and different video stuff, it is. I don’t think anybody in the country even sniffed his strikeout-towalk rate. Obviously, it’s something we do here and we value. He fit in perfectly.”  (Johns - mlb.com - 6/3/19)

2019 Season: George Kirby, RHP (No. 6)

Kirby made a name for himself as a control artist at Elon University and parlayed that into being a first-round pick in the 2019 Draft. He showed just how good that command was by not walking a single batter in 23 innings during his pro debut.

Seen as a safe pick who could ride his pitch-ability quickly up a ladder, his first full season could show that he’s more than that.

2021 Best Control – Best Control: George Kirby, RHP, Mariners (65)

In 2019, Kirby led NCAA Division I in strikeout/walk ratio (17.8) and walk rate (0.6 per nine innings) at Elon while pitching his way into the first round of the Draft. In his pro debut, he whiffed 25 batters without a single free pass in 23 innings. He has quality stuff, too, with four pitches with the chance to be solid or better, including a fastball that's still gaining velocity and can reach 98 mph.

2021 Season: The Mariners chose Kirby with the 20th pick in the 2019 draft, making him the highest-selected player ever from Elon University. He's since rewarded their faith by developing into one of the best pitching prospects in the sport.

Kirby split the season across High-A and Double-A, posting a 2.53 ERA and a 5.33 strikeout-to-walk ratio. He's more than a statistical wonder; he's upped his velocity without sacrificing control. He has walked fewer than two batters per nine innings as a professional. His combination of stuff and polish should allow him to become the first of a few incoming arms to debut for the Mariners in 2022.  (R.J. Anderson - Jan. 13, 2022)

Aug. 24, 2022: Virtually all the scouting reports, commentary from coaches and even a self-reflective description from George Kirby entering his rookie season centered on one theme: He throws a lot of strikes.

Yet Kirby took that skill to another level on Wednesday afternoon against the Nationals, thrusting himself into the MLB record books by beginning the matinee at T-Mobile Park with 24 straight strikes.

According to STATS, Kirby set a new high-water mark to begin a game dating back to 1988, when pitch tracking first began. The previous record was 21, achieved by the Pirates' Joe Musgrove on Aug. 30, 2018. Before that, only the Braves' Ervin Santana had reached 20, doing so on April 9, 2014.  (Daniel Kramer)

Sept 2, 2022: Mariners right-handed starter George Kirby was named AL Rookie of the Month for August.

Kirby went 4-0 in his five starts with a 2.15 ERA and a 1.32 FIP last month. His Aug. 24 start was the only one he didn’t win, but that day saw him match a couple of personal bests (seven innings, nine K’s) and set an AL/NL record by opening the game with 24 consecutive strikes.The 24-year-old righty finished August with 34 strikeouts and only three walks in 29 1/3 innings. He is the second Mariner to earn this honor in 2022, joining Julio Rodríguez, who has won it twice. Kirby is the first Mariners pitcher to be named Rookie of the Month since Michael Pineda in 2011. (B Murphy - MLB.com - Sept 2, 2022)

2022 Season: George Kirby had one of the best seasons on the Mariners in 2022, earning an A grade.

I think one of the great things that the Mariners did this year with Kirby was being strict on limiting his pitches thrown. He got to exactly 100 pitches just once, which came in his most dominant outing against the Athletics. He would go seven, allowing just three hits, walking one, allowing a single run, and striking out a career-high nine hitters.

Other than that, they kept him between 79-97 pitches in 19 of his 25 starts. The others were the 100 I previously mentioned, along with 74, 71, 69, 51, and 39. The 51 actually came in a beautiful five-inning game against the Rangers, which Game Score ranks as his 7th best game of the year.

What’s incredible about Kirby is how he mixes control with the ability to keep the ball in the ballpark. He had 15 BB in his first 22 starts, amassing 117.2 IP. Seven of those games had zero walks, and in the other 15 he had only one. He did struggle at the end of the year, but one of those (OAK) was pitching through sickness. The other was his last start against the Tigers, in which he walked three and gave up a homer.

That homer, on OCT 3, stopped a 14-start streak going back to June 27th without allowing an HR, the longest ever by a rookie pitcher. 73 IP and zero homers allowed. Oddly enough, he gave up four homers in that June 27th start.

 Kirby was dominant for the better part of the season. Just over a K per inning, just over five innings per start, and an incredibly low walk rate that led ALL OF BASEBALL until those last three starts. You see his numbers, a 3.39 ERA and a 1.208 WHIP, and think “Hmmm, that’s pretty good for a Rookie.” You’d be right… but it should’ve been even better.

Kirby’s FIP was 2.99, his ERA+ was 109, and his BABIP against was .332, 42 points above the league average. A lot of balls seemed to fall because they were dropped perfectly, not because they were hit well.

We have to talk about his postseason as well. Kirby became the first player in history to make his relief debut happen in the playoffs, and get a save during that debut. He shut down the Jays during the comeback game, locking down the Mariners WC series win. Then, against the Astros, he threw seven innings of scoreless ball, allowing just six hits, no walks, no runs, and K’ing five hitters.

George Kirby was one of the biggest positive surprises on the Mariners this year, and I think we all loved watching him. It’s easy to give him an A on the season, as the Rookie deserves every bit of that grade. It seems like special things will be coming quickly, and often, from Kirby, and I cannot wait to watch him pitch in Seattle for the rest of the decade.  (Christopher O'Day - Oct. 20, 2022)

Let’s start with the new changeup.

“I’m doing a different grip. It’s more like a split-change,” Kirby said. “It’s something I can throw with more intent, a little more deceptive coming out of my hands like a heater. Just trying to fool the hitters a little bit more, and it’s something that’s become kind of natural for me as I’ve been working at it. I’m excited to get in some games and see what it does.”

Kirby did indeed throw a lot more innings in 2022 than he did as a minor leaguer in 2021, so how did he think he held up? (Seattle Sports’ Wyman and Bob - Feb. 17, 2023)