A common phrase thrown around all spring is that “spring training stats don’t matter.” That’s partially true. While of course the numbers don’t actually count, I think spring data absolutely does matter, especially with pitchers.
Have they gained/lost velo? Added or improved a pitch? Changed a grip/shape? We learn all this and more due to spring training data. We then take this analysis and use them in fantasy drafts, articles, chats with friends, and so on.
If I’m being honest, a lot of my draft process — especially in a toss-up scenario or in the later rounds — is going to be based on these small sample sizes of data we see in spring. And thus far, it’s worked. So let’s dive into a few spring stocks I’ve seen surging over the past few weeks.
Note: ADP and Rostered% via FanTrax
Richard Fitts, RHP, Boston Red Sox
Fitts has been ultra-impressive ever since he made his major league debut with Boston last season, where he tossed 20.2 solid innings, allowing just 4 earned runs (all in his last appearance) and striking out nine.
The next step for Fitts in his development as a starter was to generate more whiffs at the major league level. He excelled at doing so in the minors, especially with his secondary pitches (near or above 30%), but saw his total whiff rate drop to a measly 15.2% in the show.
Fitts’ whiff rates by level (2024), via Baseball Prospectus:
| Pitch Type | AAA Whiff% | AAA xWhiff% | MLB Whiff% |
| FF | 18.6 | 27.0 | 16.4 |
| SL | 28.9 | 38.0 | 14.9 |
| SW | 28.9 | 44.0 | 13.0 |
| FS | 33.7 | 41.0 | 14.3 |
In an effort to maximize his whiff-ability, Fitts got into the lab and added a couple ticks onto his fastball. Yes, plural. His average fastball velo has seen a major increase this spring, topping out at 99 mph and sitting in the 97 range. For reference, his average fastball velo sat 94.5 mph last season and topped out at 97.2 in the majors.
In my opinion, Fitts’ best pitch is his sweeper, and it seems Andrew Bailey and the Red Sox pitching development system agree, more than doubling it’s usage this spring. The pitch graded out really well in the minors last year and has only gotten better. His slider and splitter have also taken steps forward.
Additionally, Fitts has added a sinker, curveball, and now most recently a kick-change to his growing arsenal.
In his final spring outing, Fitts dominated Mexico’s Sultanes de Monterrey, allowing no earned runs over six innings, generating 12 whiffs and striking out five batters.
With notable injuries in the Red Sox’ rotation — Brayan Bello, Lucas Giolito, and Kutter Crawford all set to miss time at the start of the year — Fitts finds himself in the fourth rotation spot for Boston to start the year. He’s a must-draft in any serious fantasy league.
Fitts’ ADP has been cut significantly and is now in the 690 range… still a bargain if you ask me! His rostered% (39%) is the highest it’s ever been and has seen over a 31% increase since the second week of March.
Clay Holmes, RHP, New York Mets
Clay Holmes‘ stock as a starting pitcher has never been higher in his career, and it’s all thanks to his tremendous performance this spring.
Holmes has tossed 19.1 innings of two-run ball, allowing just seven hits, and striking out 23 batters over that stretch. He leads all qualified arms with a .109 BAA this spring and his 0.78 WHIP is ranked fourth. He also ranks inside the top 10 in ERA, FIP, and K%.
As I noted in this article, Holmes now utilizes a 6-pitch mix (SI/CH/SW/SL/FC/FF) that can both generate an absurd amount of whiffs and induce ground balls… a deadly combination. His new kick-change is elite, and that’s been clear in the games where statcast is available. He’s also added a cutter, and both the slider and sweeper have taken steps forward.
Holmes will be given plenty of run in the starting rotation. New York’s Opening Day rotation, if not a weak point (on paper) heading into 2025, is already banged up. Veterans Frankie Montas (strained lat) and Sean Manaea (strained oblique) both went down in February. Top pitching prospect Christian Scott (Tommy John surgery) is likely out of the picture in 2025 as well.
Mets’ manager Carlos Mendoza officially named Holmes the Opening Day starter over a week ago, which has led to over a 30% increase in rostered%.
José Alvarado, LHP, Philadelphia Phillies
Alvarado, 29, is looking to bounce back in a big way in 2025. Last season, he posted a 4.09 ERA/3.80 FIP in 61.2 IP, well over half a run above his career numbers. Most notably, his K rate dropped by a whopping 12.8%.
Good news for Philly fans: it’s safe to say Alvarado is back. He’s come into camp determined, making nine scoreless appearances, allowing just three hits and striking out 20 batters — good for the most Ks among relievers this spring and a 58.8% K rate.
It’s the pure stuff that’s looked different, too. His sinker topped out at 102.4 mph this week, a career-high, and has consistently sat in the 100 mph range. The curveball and cutter have also returned Stuff+ grades that are through the roof… most recently over the 145 mark!
Veteran right-hander Jordan Romano is still listed as the Phillies’ closer, per FanGraphs’ roster resource, but I would expect Alvarado to be throwing in a lot of meaningful innings this season. He projects to be the #1 left-hander out of the bullpen after Matt Strahm went down with shoulder inflammation. Tanner Banks is his only competition.
My advice: buy stock while you still can. His Rostered% keeps ticking up each week, this week sitting at 33%, over a 30% increase since the start of March.
Hayden Birdsong, RHP, San Francisco Giants
Birdsong, 23, was marvelous in the minors to start the year, pitching to a 2.51 ERA and striking out 31.1% of batters he faced in 57.1 innings before being promoted to the majors. It was there where he struggled, posting a 4.75 ERA/4.67 FIP, 1.39 WHIP, and an alarming 13.7% BB rate.
He’s put that behind him entering camp, tossing 12 innings of one-run ball (including his current 10 IP scoreless streak), allowed just six hits, and has struck out 18 batters. His 41.9% K rate ranks fourth among major leaguers (min. 10 IP). Perhaps the most impressive part? He has not walked a batter yet and has thrown an incredible 89/106 pitches for strikes (83.9%).
Outside of the obvious fact Birdsong’s BB rate (0%) ranks first among all arms this spring, his FIP (1.25), xFIP (2.29), K/9 (13.5), WHIP (0.50), and K/BB (18) all sit inside the top ten among qualified big league arms.
While the Giants did opt to go with 26 year-old righty Landen Roupp in the rotation to start the year, Birdsong’s stellar spring performance landed him a spot on the Opening Day roster in a bulk bullpen role. I expect to see a lot of him this year.
His Rostered% shot all the way up to 71% with nearly a 40% increase since the start of the month.
Adapted by Kurt Wasemiller (@kurt_player02 on Instagram & Threads, @kuwasemiller.bksy.social on BlueSky)