RADIO
Elliott looks at pitchers with surprising starts recently. These SPs could emerge as fantasy baseball waiver wire targets for Week 22 in 2025, or just mirages.
Welcome back to the "Are You For Real?" series as we dive into Week 21 of the 2025 fantasy baseball season. For those unfamiliar, this is a weekly column where we examine starting pitchers who had surprisingly strong starts over the past week and put them under the microscope to determine whether they're legitimate or just smoke and mirrors.
This week we head west, as we'll be breaking down three pitchers who play for western division teams in MLB. First, we'll deep dive Jason Alexander's recent hot streak in Houston. Then, we'll look at Jack Leiter's dominance on Saturday against Cleveland. We'll finish it off by putting Nestor Cortes under the microscope after one-hitting the Dodgers.
Roster percentages are taken from Yahoo! and are accurate as of August 25.
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Jason Alexander, Houston Astros – 18% Rostered
2025 Stats (prior to this start): 43.2 IP, 4.74 ERA, 4.67 FIP, 8.9% K-BB%
08/20 @ BAL: 5.1 IP, 8 H, 2 ER, 1 BB, 3 K
Alexander continued his hot run with the Astros on Thursday, holding Baltimore to just two runs over five and a third innings. Alexander has picked his game up as of late, posting a 1.54 ERA through August thus far. It’s been an up and down year for Alexander, who began the season with the Athletics but was DFA’d in May and claimed by Houston. Have the Astros found something in Alexander?
An undrafted free agent out of college, Alexander signed with the Angels at age 24, making him old for rookie ball and ultimately old for all the levels throughout the minor leagues. He bounced around the minors for a few different organizations before finally making his big league debut at 29 with Milwaukee in 2022.
That was the last time Alexander pitched in the majors prior to this season, though he was still toiling away in the minors waiting for his shot. Alexander works with four primary pitches, a sinker, a changeup, a four-seam fastball, and a sweeper. He has thrown the occasional cutter or slider this season, but he’s thrown under 10 pitches total for each offering, so those aren’t a big part of his game.
His most used pitch this season has been the sinker, throwing it 38.3% of the time. He used it slightly less on Thursday against the Orioles, throwing it just 31% of the time. A 91.1 mph offering, Alexander’s sinker is on the softer end of things in terms of velocity, ranking in just the 12th percentile for fastball velo. Batters have clobbered this pitch as well, hitting .325 off Alexander’s sinker along with a .458 SLG and a .372 wOBA.
The expected stats are somehow even worse, with a .344 xBA, .493 xSLG, and a .394 xwOBA. Alexander also has a comically low 4.6% whiff rate with his sinker. Sinkers are not known for being strikeout pitches, but a sub-5% whiff rate is microscopic. Between the low velocity and poor outcomes it would be easy to write off Alexander’s fastball as a dud, but he does have some exceptional movement with this pitch.
Alexander’s sinker has 32.2 inches of drop, well above the league average. He’s excelled at keeping the pitch down and inducing groundballs, putting up a 57.9% groundball rate with his sinker this season, along with a 1-degree average launch angle against. Alexander has consistently put up plus groundball rates throughout his time in the minor leagues, and I think he could be an above average groundball pitcher in the major leagues.
Alexander’s next most used pitch has been the changeup, which he’s thrown 32.3% of the time this season. The changeup has been Alexander’s best pitch, stymieing batters for a .164 AVG, .373 SLG, and a .259 wOBA on the year. The expected stats support these results as well, with a .174 xBA, .330 xSLG, and a .253 xwOBA. It’s also been an excellent strikeout offering, with Alexander sporting an impressive 41.4% whiff rate with his changeup this season. He only got six whiffs in this start against Baltimore, but five of them were with the changeup.
An 80.3 mph offering, Alexander’s changeup is noteworthy for its exceptional movement. He has plus vertical drop and horizontal break with the pitch, giving it a unique shape that can be tough for batters to pick up. Here are a few examples of the pitch.
— Elliott Baas (@ElliottBaasBB) August 25, 2025
— Elliott Baas (@ElliottBaasBB) August 25, 2025
Looks good there, and Alexander has increased his changeup usage since coming to Houston, throwing the pitch 33.6% of the time with the Astros versus 28.8% with the Athletics. His changeup has performed even better in Houston as well, with opponents hitting a paltry .119 with a .254 SLG since Alexander came to the Astros.
The changeup looks like an effective offering that Alexander has wielded to both lefties and righties this season, and should continue to serve him well on the mound. I don’t think this pitch alone is enough for Alexander to hack it as a full-time MLB starter, but it’s good enough that he could at least be a reliever long term. Not bad for an undrafted free agent that debuted at 29.
Alexander’s next most used pitch has been the sweeper, which he’s thrown 17% of the time this season. A 78.6 mph offering, Alexander’s sweeper has been thoroughly handled by opponents. Batters are hitting .304 with a .565 SLG and a .405 wOBA off Alexander’s sweeper. With just a 25.8% whiff rate, Alexander’s sweeper is woefully below the mark in terms of strikeout potential.
He got zero total whiffs with the pitch on Thursday as well, throwing it 15% of the time in that start. His sweeper usage has decreased by 2% since coming to Houston, and ultimately I think that’s a good thing for Alexander. The sweeper is soft and ineffective, and if a pitcher can’t get batters to chase a sweeper, why even throw it? An 18.9% chase rate just isn’t going to cut it for a breaking ball.
One pitch that Alexander has begun using more often is his four-seam fastball. He only threw the four-seamer 8.2% of the time with the Athletics, but has thrown it 11.3% of the time with Houston, including 23% usage in this start. A 92.1 mph offering, the four-seamer is a little harder than Alexander’s sinker, but obviously still well below league average.
Interestingly, batters have really struggled against this pitch, hitting just .167 with a .333 SLG and a .260 wOBA. The expected stats suggest that these results are not sustainable, with a .307 xBA, .490 xSLG, and a .376 xwOBA. Alexander doesn’t have much gas to his heater, but he does have 13.4 inches of arm side run with his fastball. That gives it a unique shape that deviates from what hitters anticipate from a typical four-seam fastball. I don’t think plus movement will save this from being a below average offering that Alexander sort of mixes in in addition to the sinker.
Verdict:
Ultimately, I’m not sure there’s a major league caliber starter here. Alexander does have a plus changeup, but poor fastball velocity and a downright bad sweeper really hamstring his repertoire. His sinker does a good job at getting groundballs, and he’ll likely need them as plenty of batters will reach base against this pitch.
Alexander sort of has some funky movement with his pitches, but it’s not enough to sustain him three times through the order. I think his future is in the bullpen as a changeup/groundball specialist. That being said, Alexander is pitching well enough right now that I think he’s streamable in the right situation. His next scheduled start is for Thursday at home against the Rockies, and it doesn’t get much better than that for matchups. I wouldn't plan on him being a long term piece, however.
Jack Leiter, Texas Rangers – 33% Rostered
2025 Stats (prior to this start): 108.2 IP, 4.06 ERA, 4.61 FIP, 9.3% K-BB%
08/23 vs. CLE: 7 IP, 2 H, 0 ER, 0 BB, 10 K
Leiter had the best start of his young career on Saturday, fanning ten Guardians en route to his eighth victory of the season. The former second overall pick, Leiter had lofty expectations coming out of college, but hasn’t quite lived up to them yet. Was this the start of Leiter tapping into that talent, and taking the next step in the major leagues?
Most baseball fans know Leiter’s backstory already, but if you’re unfamiliar, Leiter was a college phenom alongside Kumar Rocker at Vanderbilt, and Leiter was taken second overall by Texas in 2021. The son of accomplished former big league pitcher Al Leiter, Jack was a huge prospect in the Rangers system, and was viewed as a future frontline starter. Leiter works with a five pitch mix consisting of a four-seam fastball, slider, changeup, sinker, and curveball.
Leiter’s most used pitch this season has been the four-seam fastball, and that was no different on Saturday. Leiter used the pitch 48% of the time against Cleveland, nearly 12% higher than his season-long usage rate of 36.5%. The fastball was on for Leiter, who earned six of his 12 whiffs with it in this start.
Averaging 97.3 mph on the gun, Leiter brings some serious heat with his fastball, even touching 99 mph in this start. Leiter also has an exceptional 6.9 inches of extension, which is even more impressive since Leiter is only 6’1”. That amount of extension improves a pitch’s perceived velocity, because the higher a pitcher's extension, the shorter the distance between where the ball is thrown and home plate.
It’s not all about the velocity for Leiter either, as he averages 2419 RPM in spin rate and has averaged 17.5 inches of induced vertical break with the pitch. That amount of break gives the pitch exceptional rise. Here’s a look at his pitch movement profile (four seamer in red).
That type of movement can be tough for batters to both read and square up, making the pitch difficult to hit. And it has been difficult for batters against Leiter’s four-seamer this season, as opponents are hitting just .185 with a .309 SLG and a .293 wOBA off the pitch. The expected stats suggest that a little regression may be coming, as Leiter has a .224 xBA, .421 xSLG, and a .344 xwOBA against his four-seamer.
Leiter keeps the ball up the zone where batters have a tough time catching up to the heat and movement. His 23.3% whiff rate is good for a fastball, and Leiter is capable of getting plenty of swings and misses with this pitch. Don’t expect 10 strikeouts on a regular basis, but he can rack up whiffs with this pitch. Leiter possesses an outstanding four-seamer that should be able to serve as the anchor to his arsenal.
The four-seamer is great, but what else does Leiter have up his sleeve? His next most used pitch this season has been the slider, which he’s thrown 24% of the time. He only threw it 12% of the time in this start, and his slider usage has been trending down. This began on a July 11 start against the Astros, where Leiter only threw it 12.6% of the time. Since July 11 Leiter has only thrown his slider 16.4% of the time, an 8% reduction.
Why the change? Perhaps it’s because Leiter’s slider hasn’t been an effective strikeout pitch. Batters are only hitting .234 off the slider, but Leiter also has a pedestrian 27.3% whiff rate. Usually there is a much bigger gap between the whiff rate on a pitcher’s primary fastball and primary breaking ball, but for Leiter it’s just 4%. The slider has painfully average movement and Leiter has lived in the zone with it with a 53.6% zone rate.
The slider isn’t a bad pitch or a liability for Leiter on the mound, but it’s also nothing special and perhaps Leiter is toying with his pitch mix to try and get better results. Leiter put up some nutty strikeout numbers in the minor leagues, but hasn’t been able to replicate those results in the majors. Perhaps a new approach can get him closer to those levels, though I doubt we’ll ever see strikeout rates around 30% for Leiter in the big leagues.
If Leiter isn’t throwing his slider as much, what is he throwing instead? That would be the changeup, which went from 14.2% usage prior to July 11 to 20.5% usage since July 11. A 90.7 mph offering, Leiter’s changeup is harder than some pitcher’s fastballs. Leiter also gets 31 inches of drop with the pitch, which is solidly above average. Here’s an example from this start.
— Elliott Baas (@ElliottBaasBB) August 25, 2025
That was a particularly hard one, but it has good strong movement and has been effective against batters this season. Opponents are hitting just .203 against Leiter’s changeup along with a .328 SLG and a .284 wOBA. The expected stats suggest that Leiter has earned these results, with a .208 xBA, .346 xSLG, and a .292 xwOBA. He also has a strong 32.2% whiff rate with the changeup, making it a good strikeout offering.
He has mostly thrown the changeup to lefties, but he has mixed it in to righties as well this season. This isn’t a standout pitch in the same way Leiter’s four seamer is, but this is a solid changeup that could serve as a nice complement to the fastball. Again, don’t expect strikeouts on this level on a regular basis, but I think he could sustain a 22-25% strikeout rate with this arsenal.
The four-seamer, slider, and changeup have been his three primary pitches, especially since July 11 when he began throwing more changeups. He does have a sinker that he throws 14.9% of the time. The sinker pales in comparison to his four-seamer in terms of effectiveness. Batters are hitting .268 off the sinker with a .380 SLG and a .321 wOBA.
That doesn’t seem so bad, but Leiter has a .334 xBA, .610 xSLG, and a .430 xwOBA with this pitch as well. Batters have pulverized the ball for a 92 mph average exit velocity and a 16-degree average launch angle against. Leiter’s sinker has below average vertical drop and doesn’t generate the groundballs we’d want to see from a sinker, with just a 32.8% groundball rate. Leiter has been throwing the sinker less and less throughout the year, and I think that’s a wise choice given the rest of his repertoire.
Leiter also throws an 81.6 mph curveball, but only 9.3% of the time. His usage was up in this start, throwing it 13% of the time. He’s gotten some interesting results with this pitch, with opponents hitting .259 with a .481 SLG and a .341 wOBA. He’s surrendered plenty of power with the pitch, and his .502 xSLG suggests that he’s deserved these results.
The curveball does not have exceptional spin or drop, but has a strong 32.3% whiff rate. He’s mostly used the curveball against lefties, either as a first pitch surprise or when in even or ahead in the count. Leiter could use a better breaking ball as his slider isn’t the strongest, and maybe the curveball could be that pitch for him. It does seem like a solid offering for his battles against lefties along with his four-seamer and changeup. Overall, Leiter has been much better against left-handed batters, posting a .267 wOBA versus lefties and a .332 wOBA versus righties.
Verdict:
When everything is working for him, Leiter is must see TV. The young fireballer possesses a deadly four-seam fastball, notable not only for its 97.3 mph velocity, but for its 17.5 inches of induced vertical break, giving it a unique combination of velocity and movement that has confounded opponents to a .185 AVG against. Leiter even gets 6.9 inches of extension with his delivery, improving the pitch’s perceived velocity. A 97 mph fastball from Leiter might seem like 99-100 to an opposing hitter. Leiter’s fastball has everything we’d want to see from a four-seamer, and he should be able to use this pitch as a great foundation towards success.
Whether he finds that success will depend upon the effectiveness of his secondary stuff. Leiter is breaking ball away from being a topline starting pitcher, but I’m not sure any of his current offerings are enough. His most used breaking ball has been an 87.7 mph slider, which he’s been using less and less over the last six weeks. It hasn’t been a great pitch, with the most concerning number being a pedestrian 27.3% whiff rate.
His changeup has been a little better with a 32.2% whiff rate and looks like it could be his best secondary offering, but the fastball and changeup alone aren’t enough to carry him to consistent success. I think when the fastball is on for Leiter he can’t be touched, like on Saturday, but those starts may not happen very often. From a start by start basis we’re going to see ups and downs at this stage of his career. Leiter is still a work in progress, but a very talented one. I think he could be a nice add if you’ve missed out on the recent waiver wire rush around guys like Hurston Waldrep, Nolan McLean, and Shane Bieber, but he likely won’t be as consistent or reliable as those guys because they have deeper arsenals.
Nestor Cortes, San Diego Padres – 19% Rostered
2025 Stats (prior to this start): 23 IP, 5.87 ERA, 8.50 FIP, 6.6% K-BB%
08/23 vs. LAD: 6 IP, 1 H, 0 ER, 0 BB, 3 K
Cortes got some World Series redemption against those pesky Dodgers on Saturday, holding them to just one hit over six innings of shutout ball. The crafty lefty has had a year filled with injuries and a trade, but he’s finally healthy and ready to contribute down the stretch for San Diego. Can he do the same for our fantasy teams?
Originally a 36th round pick by the Yankees back in 2013 out of high school, it’s safe to say that Cortes was not a big prospect coming up through the minors. He was passed around the league a few times before finally finding success with the Yankees in 2021, where he became a reliable southpaw for them. Between 2021-2022 Cortes posted a 2.61 ERA and 0.98 WHIP in 251.1 innings, impressive numbers.
He was even solid last season with a 3.87 ERA in 174.1 innings, but was out from April 6 to August 3 with a strained elbow flexor. Cortes works with a five pitch mix, consisting of a four-seam fastball, cutter, changeup, sweeper, and sinker. He’s only thrown five sinkers all season, so it’s mostly been about the other four pitches for Cortes.
His most used pitch this season has been the four-seam fastball, but that wasn’t the case on Saturday. Instead, Cortes relied on his cutter more often, throwing it 38% of the time against Los Angeles. The cutter is Cortes’ signature pitch, with it serving as a key piece to past success. Here's an example from earlier this season.
— Elliott Baas (@ElliottBaasBB) August 25, 2025
An 86.7 mph offering, Cortes’ cutter is noteworthy for its exceptional movement. He gets 10.8 inches of induced vertical break and 4.9 inches of glove side movement. Here’s a look at his 2025 pitch movement profile (cutter in brown).
A cutter with that type of movement can be incredibly difficult to read and square up for opposing hitters, and Cortes has gotten some excellent results with the pitch this season. Batters are hitting just .150 off Cortes’ cutter with a .350 SLG and a .284 wOBA. He only has a 21.9% whiff rate so he’s not getting a ton of swings-and-misses with the pitch, but that was never really the case for Cortes’ cutter anyway. When the cutter is working for him it’s inducing lazy flyballs for his fielders to put away with ease.
Cortes does have a 25-degree average launch angle against his cutter this season, along with a 54.5% flyball rate. Flyballs are the least likely batted ball type to land for a hit, so it can be a favorable approach for a pitcher to induce a lot of them. It can be risky as flyballs also tend to lead to the most power outcomes, and Cortes has an ugly 1.48 HR/9. Pitching his home games in San Diego should help keep the ball in the yard, but home runs could be a issue for Cortes going forward with this flyball-heavy approach.
The cutter was working for him, but what about the heater? A 90.4 mph offering, Cortes is one of the softest throwing starters in the majors, ranking in just the 6th percentile for fastball velocity. Obviously, Cortes isn’t going to blow anyone away with heat. He’s survived in the majors thanks to some funky movement on the four-seamer, with a whopping 19.4 inches of induced vertical break, tied for ninth-most in the majors.
Cortes has only averaged 2248 RPM with his fastball this season but has a 98% active spin rate, which means that 98% of the spin on his fastball was contributing to its movement. Basically, Cortes is optimizing his spin rate to get the most out of what would otherwise be considered a mediocre fastball. Again, this makes the pitch difficult to read and square up for opposing hitters. Let’s peek at that movement profile again (four seamer in red).
That is a good fastball shape with tons of rise, though batters have handled Cortes’ four seamer well thus far. Opponents have a .350 AVG, .875 SLG, and a .543 wOBA off Cortes’ fastball this season, including seven home runs allowed in just six starts. Those numbers were influenced by an eight-run, five-homer shellacking at the hands of the Yankees at the beginning of the season.
I don’t think Cortes’s fastball is quite this bad, and the expected stats agree with a .250 xBA, .692 xSLG, and .440 xwOBA. Still ugly power numbers, but it’s a small sample size. I wouldn’t expect Cortes to allow this many homers over the course of the season, but I do think it will remain a problem for him to some degree, as it has long been an issue for him.
The fastball and cutter are Cortes’ bread and butter, but one pitch that was working for him on Saturday was the sweeper. He only throws it 12.4% of the time, but he threw it 19% of the time against the Dodgers in this start. He also racked up five whiffs on eight swings, good for a monster 63% whiff rate. A 78.2 mph offering, the sweeper is a softer, loopier pitch compared to the cutter.
It has below average drop and break for a sweeper, and doesn’t usually rack up whiffs like we saw on Saturday. Cortes only has a 28.6% whiff rate with his sweeper, and I’d consider anything sub-30% underwhelming for a breaking ball. Batters have really struggled against this pitch however, with a .091 AVG, .091 SLG, and a .131 wOBA against. Cortes currently has a BABIP against his sweeper compared to a career .299 BABIP against, so I think it’s fair to say that regression is coming.
The sweeper has become a bigger part of Cortes’ game over his last two starts, throwing it 19% of the time in each appearance. Perhaps he and the Padres are playing with his pitch sequencing a bit and trying the sweeper more often, but it’s too early to say. I don’t think increased sweeper usage like this would drastically change Cortes’ possible outcomes.
Cortes also works with a changeup, though he only threw it 10% of the time against the Dodgers compared to 13.9% season usage. An 82.4 mph offering, Cortes’ changeup has performed very well in a limited sample this season. Batters are hitting just .143 against the pitch with a .214 SLG and a .153 wOBA.
Cortes also has an outstanding 46.7% whiff rate with his changeup this season, along with an 82.7 mph average exit velocity and a -7-degree average launch angle. Batters have barely hit it, and when they do, they’ve sent it weakly into the dirt. These are great outcomes, but it’s unlikely that Cortes is able to keep this up with his changeup, especially the whiff rate. He’s never had a whiff rate higher than 32% with his changeup, so it would be foolish to expect him to maintain anything close to 46.7%. The changeup could be a fine offering for Cortes against righties, but it’s not a standout pitch.
Verdict:
Is Nestor Nasty again? A few things were working for him in this start, mainly his cutter and sweeper. He commanded the cutter well in this game and did a good job navigating a tough Dodgers’ lineup. The cutter has above average drop and break and does an excellent job of inducing flyballs. A flyball-heavy approach can be risky and Cortes has had home run issues throughout his career, but San Diego might just be the perfect home for him.
I’m still worried about his chronic Gopheritis and he just gave up three homers in the start before this one. The sweeper got five whiffs with a 63% whiff rate, but he likely won’t be racking up big strikeout totals with it anytime soon. The sweeper is soft with poor movement and only really works when the cutter is working, but that's Cortes in a microcosm.
His 90.4 mph fastball may not impress anyone on the gun, but he does get remarkable movement with 19.5 inches of induced vertical break. That unique fastball shape leads to more flyball outs, which could lead to more home runs as well. Cortes will likely never reach the heights of his 2021-22 campaigns again, but he could be a solid streaming option.
My issue with Cortes is that he’s got both a low floor and a low ceiling. He’s given up nine home runs in six starts this season and is liable for a blowup in any given start. At the same time, when he’s at his best he still doesn’t produce big strikeout numbers as evidenced by just three in this game. He’s not someone I’d want to pick up and keep, but I’d stream him in the right matchup. His next start is scheduled for Friday at Minnesota, and I think he’s usable in that game.
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