It's been the kind of year that reminds us just how much can change over the course of six months, which is a lesson some of us had to re-learn after the pandemic-shortened 2020 season.

I've chronicled the changing Dynasty value of various players along the way, but the evaluations depicted here have a greater finality to them given that they'll be cryogenically frozen for the next six months. Our 2022 assessments will begin with them, in other words.

To be clear, these aren't the players who've seen their value change the most over all of 2021. They're just the ones most worth highlighting since the last edition of Dynasty Stockwatch in early August.

Players who've gained the most value
Sandy Alcantara SP
MIA Miami • #22 • Age: 29

2021 Stats

W-L

9-13

ERA

3.05

WHIP

1.06

INN

194.2

BB

49

K

189
While Sandy Alcantara has been a success basically since he first arrived in the majors, the knock on him had always been that, for all his mind-bending stuff, he didn't miss enough bats. Well, that's out the window now. He's currently enjoying an eight-start stretch with a 16.3 percent swinging-strike rate that would rank second among all qualifiers. It hasn't come at the expense of his usual workload either. Six of those eight starts have been seven innings or more, and three have been eight or more. If the transformation is legitimate -- and it would be awfully difficult to fake -- he's become everything you could want in an ace. Now, it's just a matter of the Marlins supporting cast catching up.
Frankie Montas RP
NYM N.Y. Mets • #47 • Age: 31

2021 Stats

W-L

12-9

ERA

3.57

WHIP

1.21

INN

174

BB

53

K

192
If there's any pitcher who's managed to hang with Sandy Alcantara over the past two months, it's Frankie Montas. But actually, his transformation goes back further, to when he doubled up his splitter use in July. It's the pitch that put him on the map in 2019, and it's led to a 2.34 ERA, 1.07 WHIP and 10.8 K/9 over his past 13 starts. Hard to say why he wasn't emphasizing the pitch previously. Perhaps it's one he'll occasionally lose and have to regain the feel for, making his full-season statistics more indicative than this latest stretch. Still, we know now that the 2019 breakthrough was legitimate, which wasn't so clear given his struggles last year and early this year.
Jorge Polanco 2B
SEA Seattle • #7 • Age: 31

2021 Stats

AVG

.272

HR

31

RBI

90

R

91

OPS

.836

AB

551
Another 2019 breakout whose abbreviated 2020 undermined whatever confidence we had in him, Jorge Polanco has taken an even bigger step forward this year, combining excellent contact skills with one of the lowest ground-ball rates in the league. It's worth pointing out that he was batting .225 with a .686 OPS as late as June 1, perhaps still feeling the effects of offseason ankle surgery, but it makes the turnaround all the more impressive. Since then, he's batting .295 with 26 homers and a .909 OPS in just 93 games, overtaking established studs like Xander Bogaerts and Jose Altuve along the way.
Logan Webb SP
SF San Francisco • #62 • Age: 28

2021 Stats

W-L

10-3

ERA

2.79

WHIP

1.10

INN

132.1

BB

32

K

141
It took him a while to get going between injuries and an unsteady role, but ultimately, the hype Logan Webb received in spring training has proven to be more than justified. In 14 starts since returning from a strained shoulder July 9, the 24-year-old has a 2.16 ERA, 0.98 WHIP and 9.4 K/9, going six innings or more in 11 straight. His 61.1 percent ground-ball rate would rank a distant first among qualifiers, and his 2.76 xFIP would rank second, behind only Corbin Burnes.
Tyler O'Neill LF
BAL Baltimore • #17 • Age: 29

2021 Stats

AVG

.280

HR

28

SB

13

OPS

.883

AB

435

K

157
It's a weird profile that Tyler O'Neill brings to the table -- particularly with the 32.1 percent strikeout rate -- but he's made it work all season and especially since the start of August, a stretch that has seen him hit .311 (47 for 151) with 11 homers, four steals and a .984 OPS. The 26-year-old has long tantalized Fantasy Baseballers with his Popeye physique and surprising athleticism, but only this year have the Cardinals committed to playing him every day -- and you see the results. His average exit velocity and hard-hit rate are both at the top of the scale, which is how to make a strikeout rate like his work.

Prospects who've gained the most value

MJ Melendez, C, Royals

AA/AAA: .278 BA (410 AB), 38 HR, 90 RBI, .993 OPS, 71 BB, 105 K

You think a catcher like Salvador Perez leading the majors in home runs is impressive? Melendez, another catcher, is doing the same in the minors. Never has that happened before, a catcher leading both the majors and minors, much less within the same organization. The Royals overhauled their hitting development department prior to last season, which led to Melendez reworking his swing at the alternate training site. Still, it's hard to believe this is the same guy who hit .163 with a .571 OPS two years ago.

Nick Yorke, 2B, Red Sox

A/A+: .325 BA (378 AB), 14 HR, 20 2B, .928 OPS, 52 BB, 69 K

The Red Sox went off the board in taking Yorke 17th overall two years ago, presumably so they could pay some of their later picks more, but their faith in him has been handsomely rewarded in his first full professional season. He was actually slow out of the gate, too. Take out the first month, and he'd have hit .361 with all 14 of his home runs and a 1.048 OPS. The contact hitting was expected, but the power was a pleasant surprise. He's only 19, too, so it's not like he was beating up on younger competition.

No ad available

Matt Brash, SP, Mariners

A+/AA: 6-4, 2.31 ERA, 1.14 WHIP, 97 1/3 IP, 48 BB, 142 K

Brash may have finished the year with a couple bumpy outings, but the impression was already made, his slider now being regarded as one of the best in all the minors. You can judge for yourself:

It isn't all he has going for him either. The fastball pushes triple digits, and the changeup looks good enough to get him a third time through the order. The Mariners let him go more than five innings in six of his final seven starts at Double-A, so they're not slow-playing him. Pretty good for a guy traded straight-up for nothing reliever Taylor Williams last year.

Vinnie Pasquantino, 1B, Royals

A+/AA: .300 BA (437 AB), 24 HR, 37 2B, .957 OPS, 64 BB, 64 K

One of this year's more underrated stats is that Pasquantino closed out the season with the exact same number of extra-base hits and walks as he had strikeouts (64). It tells you just how advanced he is as a hitter, and it seemed like he was finally beginning to attract some attention when the Double-A season came to an end. It took so long because the Royals had another breakout first baseman a step higher on the organizational ladder (Nick Pratto), which made Pasquantino seem like an also-ran. Worth noting, though, that the Royals have begun experimenting with Pratto in the outfield.

Daniel Espino, SP, Indians

A/A+: 3-8, 3.73 ERA, 1.12 WHIP, 91 2/3 IP, 39 BB, 152 K

No ad available

Espino was a name prospect hounds were aware of coming into 2021, but because he had only 23 2/3 minor-league innings to his name, he wasn't exactly a hot commodity in dynasty leagues. The road is littered with failures who once met the description of "20-year-old with stuff," after all.  In Espino's case, though, the theoretical has now been realized. His ERA may have been a bit on the high side, but his 14.9 K/9 led all minor-leaguers with at least 15 starts. Cleveland has shortened his arm action to address durability concerns, but he still hits 101 on the radar gun.

Players who've lost the most value
Trevor Story SS
BOS Boston • #10 • Age: 32

2021 Stats

AVG

.247

HR

23

SB

19

OPS

.802

AB

489

K

131
Trevor Story hasn't exactly been useless this year, but he has fallen short of expectations and hasn't been able to the right the ship even while inexplicably getting to finish out his contract year in Colorado. Now, he enters free agency almost certain not to return. With a career .242/.311/.444 slash line away from Coors Field and coming off the season he's had, it's hard to envision Story ever returning first-round value again, so hopefully you had the foresight to move him already.
Nolan Arenado 3B
STL St. Louis • #28 • Age: 33

2021 Stats

AVG

.255

HR

33

OPS

.810

AB

561

BB

45

K

89
To some degree, Nolan Arenado is our window into what's about to happen to Trevor Story, except that Arenado's consistently low strikeout rate made him even less dependent on Coors Field's BABIP-boosting effects. Still, it's clear he's not the same hitter without them. He's still a valuable one -- must-start, even -- but instead of being the player you build around, he's a low-OBP slugger who figures to go off the board in the Round 6-8 range in redraft leagues. Combine a high fly-ball rate with a middling hard-hit rate outside of Colorado, and this is what you get.
Zac Gallen SP
ARI Arizona • #23 • Age: 29

2021 Stats

W-L

2-10

ERA

4.53

WHIP

1.32

INN

109.1

BB

45

K

125
More than the performance itself, it's the state of Zac Gallen's elbow that clouds his immediate future. Sure, he's made it back from a ligament issue and has pitched without disruption since mid-July, but it feels like we're watching a different guy than the one who transitioned so easily to the majors in 2019 and 2020. His swinging-strike rate has gone from among the best to among the worst, and he seems to have lost all feel for the cutter. If surgery isn't in his future, then what the heck is going on with him?
Trent Grisham CF
NYY N.Y. Yankees • #12 • Age: 28

2021 Stats

AVG

.236

HR

14

SB

10

OBP

.325

OPS

.725

AB

420
There were mild concerns at the start of the year that Trent Grisham could fall victim to the new "deadened" baseballs, given his relatively weak quality of contact, but those concerns were swiftly put to rest when he hit .301 with an .898 OPS over the first six weeks. Looking back, though, it kind of seems like that's exactly what's happened. His decline partly corresponds to a heel injury suffered in late May, but the free fall came a few weeks after his return, which suggests to me it was unrelated. He may still have a future because he takes his walks and runs well, but that future is a murky one.
Jeff McNeil 2B
NYM N.Y. Mets • #1 • Age: 32

2021 Stats

AVG

.252

HR

7

OPS

.683

AB

365

BB

27

K

54
You may have entered this season with questions about Jeff McNeil's power projection given that his 2020 decline happened over such a short span, but the batting average you probably figured you could take to the bank. Apart from the month of July, though, when he hit .351, the fourth-year player hasn't gotten anything going at the plate. It's difficult to pinpoint exactly what's gone wrong, unless he's just another casualty of this year's environmental changes. Clearly, power hitting is off the table now, so if he's not a lock to bat .290 or better, his grip on a starting role could be a fleeting one. He'll be 30 next year, believe it or not.