Dynasty Due Diligence: September 2026

Series Overview

This series aims to help readers conduct routine due diligence in their dynasty leagues. It makes use of up-to-date OOPSY Peak projections and my own arbitrary whims to discuss a handful of players, both prospects and major leaguers, who may have seen their perceived value shift recently. Any reference to how a player projects using the FanGraphs auction calculator uses these settings (15-team 5×5 SV 2 C) with OOPSY DC (ROS).

MLB Players

Vladimir Guerrero Jr., Blue Jays. OOPSY Peak Projection Per 600 PA: 11% BB 14% K 24 HR 7 SB 142 wRC+ -12 DEF 3.7 WAR

With Fernando Tatís Jr. rebounding from an ice-cold start, and even Cal Raleigh showing signs of life lately, Guerrero Jr. is the last slow-starting 2026 slugger left standing. He has not showed any signs of life of late, with a 71 second-half wRC+, even worse than his already extremely disappointing first-half 100 wRC+. His projections have come down somewhat across the board, but OOPSY ROS and Steamer ROS remain high on him, with 143 and 142 wRC+ projections, respectively. THE BAT X and ZiPS are slightly less optimistic, but they still see him as a top hitter. There’s only so much one down season can move a projection for a 27-year-old with a track record approaching 5,000 plate appearances as one of baseball’s premier bats.

It’d be nice to see a strong finish, with Guerrero at least reaching the 4 home runs OOPSY and Steamer expect of him the rest of the way–which would be equivalent to a full season home run pace in the mid-20s. Given the down year, he’s shaping up to be one of the best dynasty bargains of the offseason, though he’s now more of a second or third round pick rather than a first round pick.

Verdict: Guerrero Jr. is still my top dynasty first baseman so I’d be down for any challenge swaps of the first baseman for first baseman sort. Ben Rice is the only one who comes close from the perspective of OOPSY or Steamer.

Joshua Báez, Cardinals. OOPSY Peak Projection Per 600 PA: 8% BB 29% K 28 HR 30 SB 118 wRC+ -5 DEF 3.2 WAR

Báez has had a boom-bust debut, with six home runs, a 5 BB%, and a 35 K% across 63 plate appearances. OOPSY Peak has liked the debut overall, in part driven by the elite 78 MPH average bat speed he has shown in the majors. His peak projection is particularly juicy from a fantasy perspective, with a 118 wRC+, 30 stolen bases, and 28 home runs per 600 plate appearances, which would make him a dynasty building block only limited by a weaker on-base percentage.

Verdict: I’d move Randy Arozarena and a good prospect like Zyhir Hope for Báez.

Henry Bolte, Athletics. OOPSY Peak Projection Per 600 PA: 9% BB 28% K 19 HR 32 SB 119 wRC+ 1 DEF 3.8 WAR

In any park, Bolte’s power and speed would be noteworthy, but Sacramento elevates his contribution to the next level. Like Báez with less home run power and more defensive value, he looks the part of an emerging dynasty cornerstone piece, with 20-home-run power and 30-stolen-base speed, and strong outfield defense that further cements his playing time. A K% pushing 30% is plenty acceptable for Bolte and Báez considering the rest of their profiles. Usually, rookie everyday power-speed threats are off limits in dynasty leagues, but Bolte’s modest eight home run output over 376 plate appearances might mean he is still attainable in your dynasty league.

Verdict: Bolte is similar to Báez in my book but I think he is still a bit underrated so I’d just try Randy Arozarena straight up at first here.

José Ramírez, Guardians. OOPSY Peak Projection Per 600 PA: 10% BB 13% K 19 HR 36 SB 115 wRC+ 5 DEF 4.2 WAR

Ramírez had one of my least favorite preseason OOPSY projections, with a 118 wRC+, lagging the other projection systems. Ironically, he has underperformed even OOPSY’s lower mark, with a 101 wRC+ so far in 2026. In the past he has been the poster child against xwOBA given its exclusion of spray angle, an approach that ostensibly underrates Ramírez’s pull-hitter tendencies. This year, that narrative has been turned on its head: he has posted a .343 xwOBA, significantly ahead of his .318 wOBA, forcing xwOBA skeptics to reconsider their stance.

In any case, it is a testament to how good Ramírez is that he has still been a strong fantasy contributor even with diminished power as he has already exceeded 30 stolen bases. At this point, Ramírez may be undervalued in a dynasty context given his age and his superficially down 2026. At 33, he’s unlikely to return to his peak , but he should still be a top 30 dynasty hitter for a few more years.

Verdict: I’d move Colson Montgomery, Bryce Rainer, and Kevin Alcántara to land Ramírez.

Coby Mayo, Orioles. OOPSY Peak Projection Per 600 PA: 9% BB 27% K 26 HR 5 SB 120 wRC+ -1 DEF 3.4 WAR

Mayo has had a breakout second half, with 7 HR and a 142 wRC+ over 123 PA, pushing his season wRC+ to 104. His short-term value has been somewhat limited by semi-frequent benchings versus right-handed pitchers, but he’s been good enough that the benchings have been happening less often of late. He looks destined to eventually fulfill the expectations he carried as a prospect, well on his way to becoming an annual threat to pop 30 home runs. He has been below average but passable at third base, which should help keep him in the lineup regularly for the rest of 2026 and beyond.

Verdict: I’d move Michael Busch for Coby Mayo and a good prospect like Andrew Fischer. OOPSY Peak prefers Mayo but I’d want an extra piece to make up for Mayo’s riskier playing time outlook.

Bryce Miller, Mariners. OOPSY Peak Projection Per 198 IP: 22% K 7% BB 4.20 ERA 2.6 WAR

Miller’s 2026 has been a tale of two halves: in his first eight starts, he was one of the best pitchers in baseball, with a 33 K%, a 3 BB%, and a 1.71 ERA. In nine starts since then, he has been one of the worst pitchers in baseball, with a 16 K%, a 10 BB%, and a 6.65 ERA. If he had achieved the same 2026 numbers in less extreme fashion, nobody would have batted an eye as his overall numbers are in alignment with his preseason projections.

Given his Jekyll and Hyde act, his rotation spot would already be forfeit if not for a groin injury to Emerson Hancock. Miller is a good cautionary tale against putting too much weight on a player under or over-performing their projections by a huge margin, even if the under or over performance is supported by good underlying statistics. While he doesn’t have much leash this year if he continues to struggle, he is a good 2027 bounceback candidate, when he’ll project as a clear top 50 SP with the help of T-Mobile.

Verdict: I’d move Michael Soroka or Brandon Pfaadt for Miller.

Paul Skenes, Pirates. OOPSY Peak Projection Per 198 IP: 29% K 6% BB 2.99 ERA 5.3 WAR

Skenes has had a down season, with a career-worst 3.97 era. His more skill-based metrics, xFIP (3.32) and K% minus BB% (22%), are still elite, only mildly down relative to career norms. His Stuff+ is also slightly down from career norms, encapsulated by a fastball that has lost around one mile per hour in average velocity.

Skenes has been human enough this year to have been surpassed by Tarik Skubal, Jacob Misiorowski, and Cristopher Sánchez, but after those three, there’s no pitcher I’d rather have in a dynasty context; Chris Sale is too old and Garrett Crochet is too big of an injury risk, otherwise they’d be in the conversation too. It’s difficult to worry too much about Skenes’ struggles when his K%, BB%, and HR/9 are so close to where they are projected to be; there’s only so much lost effectiveness one can confidently attribute to moderately diminished stuff.

Verdict: I’d move Dylan Cease for Skenes. OOPSY Peak has them close-ish but Skenes is much younger.

Ben Joyce, Angels. OOPSY Peak Projection Per 70 IP: 25% K 11% BB 3.43 ERA 1.4 WAR

Joyce looks all the way back from shoulder surgery, with trademark legendary velocity, and an excellent 120 Stuff+. He has seized hold of the Angels closing job, fulfilling a prophecy that has long been foretold. He doesn’t miss enough bats to rank among the game’s upper echelon of closers, but he looks like a top 20 closer for the rest of 2026 and beyond.

Verdict: I’d move Emilio Pagán or Jacob Latz for Joyce.

Mason Montgomery, Pirates. OOPSY Peak Projection Per 70 IP: 31% K 9% BB 3.01 ERA 2 WAR

In the second half, Mason Montgomery has somehow been the best reliever with the initials MM, with a 39 K% minus BB% and a 0.92 ERA (compared to Mason Miller’s 36 K% minus BB% and 2.04 ERA). He has steadily ascended the saves hierarchy in Pittsburgh, fighting off competition in Dennis Santana, Gregory Soto, and Luke Weaver to claim sole posession of the throne. With a strong finish, he could be a top-five dynasty reliever heading into 2027. Perhaps he already is.

Verdict: I’d move Riley O’Brien and Yoendrys Gómez for Montgomery.

Edwin Díaz, Dodgers. OOPSY Peak Projection Per 70 IP: 31% K 10% BB 3.12 ERA 1.8 WAR

It has been a disaster year for Díaz, who will end up missing most of the year with various injuries, first a surgery to remove loose bodies from his elbow, and more recently, a minor neck issue that he is almost ready to return from. Díaz appears to have dodged long-term health issues, but he has been far from his usual ultra-effective self when he’s actually been on the mound, with a 5.26 xFIP and an 11 K% minus BB%, both easily career worsts.

Normally, he’s the kind of player I’d try to buy low on: someone with a long track record of dominance and a much smaller track record of struggles. His projections are more great than spectacular at this point, however, slightly trailing other names on the Dodgers, Edgardo Henriquez and Tanner Scott. I’d still be open to acquiring Díaz, but I’d be cautious about it. I’d prefer Mason Montgomery at this point, for instance, but Díaz could still enter 2027 as a a top 10 dynasty closer with a strong September and October.

Verdict: I’d move Raisel Iglesias for Díaz.

MILB Players

Here, I’ll give a rundown of OOPSY Peak-related developments in the prospect sphere. Each player’s projected peak full season WAR is shown in parentheses. Outside of shallow formats, each of these guys is worth considering adding if they happen to be available.

Ryan Sloan (3.9 Peak WAR) and Anthony Eyanson (3.8 Peak WAR) have both improved their already strong projections with stellar second-half performances, with peak WAR projections similar to current WAR projections for Logan Webb and Sonny Gray.

Jarlin Susana (3.8 Peak WAR) is not far behind them as OOPSY Peak’s fourth favorite pitching prospect. Susana looks fully recovered from shoulder surgery, emerging with his otherworldly stuff intact.

Next up is River Ryan (3.4 Peak WAR), whom OOPSY Peak rated as the Dodgers second best prospect before they traded him to the Tigers as the centerpiece for Tarik Skubal. He has a chance to make some starts for the Tigers in September.

Moving further down the list, David Shields (2.7 Peak WAR) and Dylan Brown (2.7 Peak WAR) have both emerged as top 25 pitching prospects per OOPSY Peak. Each has a good shot to make the 2027 OOPSY Top 100 with a strong finish. FanGraphs has highlighted elite command as well as the need for Shields to add velocity to project as more than a backend starter in the majors. FanGraphs has also described Brown’s stuff as fringy, so it remains to be seen if his dominance will keep up as he climbs the minor league hierarchy. 

On the hitting side, Rainiel Rodriguez (5 Peak WAR) has claimed the top spot from Eli Willits (4.5 Peak WAR) on the back of a scorching hot last couple of months, highlighted by a 168 wRC+ over his last 202 Double-A plate appearances. Caleb Bonemer (4.2 Peak WAR) has joined the top five hitting prospects, as well, with his massive power display across the minor leagues this year; OOPSY Peak projects him for 28 HR/600.

Max Clark (4 Peak WAR) has seen his OOPSY Peak projection improve since his debut, as he has shown solid bat speed and been above average at the plate (112 wRC+) across 118 plate appearances.

Sebastian Walcott (3.9 Peak WAR) is on the cusp of OOPSY Peak’s top 10 hitting prospects; he has been very good in his return from an elbow injury, with a 146 wRC+ across 129 Double-A plate appearances.

Catching prospect Franklin Primera (3.9 Peak WAR) is the biggest surprise name currently in the OOPSY Peak top 25 hitting prospects. He’s a catcher, limiting his fantasy appeal somewhat, but it looks like he can really hit. His exit velocities have been solid as well, with a 104.2 MPH EV90 per Prospect Savant. Another catching prospect, Boston Smith (3.6 Peak WAR) hasn’t slowed down since joining the Mariners at the trade deadline, with nine home runs across 103 plate appearances.

George Lombard Jr. (3.4 Peak WAR) has done his best Anthony Volpe (3.4 Peak WAR) impression since claiming the Yankees shortstop job, with a 90 wRC+ over 87 plate appearances; OOPSY Peak is bullish on both shortstops long-term.

Recent Mariners call-up, Lazaro Montes (3.8 Peak WAR) has ascended to the top projected prospect by both peak wRC+ (137) and peak HR/600 (34). OOPSY Peak also continues to be fond of Cardinals shortstop prospect, Miguel Hernandez (3.3 Peak WAR), Diamondbacks catching prospect, Carlos Virahonda (2.7 Peak WAR), and Blue Jays corner infield prospect, Sean Keys (3 Peak WAR).