Waiver Wire: Zack Eflin's for real

You may recall I took inventory of the dynasty landscape at the quarter-way point of the season, giving you my picks for the players and prospects who had gained or lost the most value.

Here we go again.

Another quarter of the season gone, we're halfway home now, which means we're due for another audit. For the most part, the players I selected in mid-May have lived up to it. I may have jumped the gun on Matt Olson, who has restored some of his value in the weeks since, but the shifts in value for those 15 players and prospects more or less hold.

So I'm focused more on the ones who've seen a permanent shift in value since then. If we already knew Gerrit Cole was one of the biggest gainers six weeks ago, it doesn't help to repeat it now, does it?

Same rules apply, though. I made these selections as sagaciously as I know how, recognizing that any moves you make in a dynasty league can have far-reaching implications. This isn't some pie-in-the-sky, throw-caution-to-the-wind-type experience. I need to feel confident these players actually fit these descriptions.

So that you can feel confident acting on it.

Players who've gained the most dynasty value

There's no substitute for proven-ness, so while other prospects rated similarly to Juan Soto at the quarter-way point, his successful transition pushes him into another stratosphere of value. In fact, given his 19 years of age, his advanced plate discipline and the high floor that normally goes with it, not to mention the likelihood he's a cheap keeper after a quick climb up the minor-league ladder, he may be a top 10 dynasty asset already, depending on your league's salary structure.

Learning to elevate the ball has transformed Brandon Nimmo from a flop of a prospect to an OPS monster, his .970 mark ranking behind only Mookie Betts, Mike Trout, J.D. Martinez, Jose Ramirez and Nolan Arenado. Those might be the first five hitters drafted next year. There's little reason to doubt it, too, given Nimmo's longstanding ability to get on base. The BABIP might be a little high, but considering he's the 13th-best hitter in standard points leagues since entering the lineup May 9, it's safe to assume you've stumbled into a must-start outfielder.

We had reason to suspect Eddie Rosario was good at the quarter-way point, but subpar plate discipline and a sluggish April made it an open question. After back to back months with an OPS over 1.000, though, it's fair to say he has ascended to a level we didn't even think possible, his production to date validated by a perfectly reasonable BABIP and a home run-to-fly ball rate that's actually lower than last year's. Over the past 365 days, he's batting .304 with 34 homers, 44 doubles and an .895 OPS, so we're talking a top-12 outfielder, in all likelihood.

Jose Berrios was denied a seat at the table shared by Blake Snell and Patrick Corbin in the last dynasty check-in because he had a 4.50 ERA at the time. But that was at the end of a three-start rough patch when his stuff mysteriously abandoned him, resulting in a combined four strikeouts. Between his other 13 starts, he has 10.6 strikeouts per nine innings. He has a 2.05 ERA in his past eight starts, all at least six innings and five at least seven innings. He's a 24-year-old ace at a time when aces are going the way of the dodo, and that's a beautiful thing.

You know who technically ranks sixth in OPS given that Nimmo doesn't have the at-bats to qualify? It's Eugenio Suarez, who has not only validated his breakthrough 2017 but continued to build on it, cutting down on his strikeouts in a way that hasn't at all compromised his power. With no obvious red flags in the underlying stats, he has eighth-highest point-per-game average among all hitters, and at 26, he's just getting started.

Prospects who've gained the most dynasty value

Jo Adell, OF, Angels

The Angels selected Jo Adell 10th overall in last year's draft, so it's not like no one had heard of him prior to this year. But he has emerged as the clearest success story from his draft class so far, delivering an OPS over 1.000 at each of his two minor-league stops while combining for 16 homers and 11 steals. It's the sort of the dominance that will earn a player a spot on the short list of prospects to monitor and might even move Adell into the top 10 at the start of next year.

Alex Kirilloff, OF, Twins

A high pick in 2016, Alex Kirilloff got some dynasty buzz early last year but ended up needing Tommy John surgery, which is enough to bury any prospect still working his way through the lower minors. He has come back strong, though — and by strong, I mean a .333 batting average, 14 homers and .987 OPS. Scouts loved his bat but had questioned his power ceiling, so the fact he's flashing so much already bodes well for his future.

Cavan Biggio, 2B, Blue Jays

A holdover from the quarter-way list, Cavan Biggio certainly hasn't done anything to damage his value since then, and while it's cool he's on the same team as Vladimir Guerrero Jr. and Bo Bichette, themselves sons of former major-league stars, you have to understand he wasn't a prospect on any level, much less like those two, coming into the season. He has made himself into one, though, with a power explosion that, combined with his plus plate discipline, gives him a chance of becoming a Ben Zobrist-style utility player in the majors.

Chris Paddack, SP, Padres

The Marlins made prospect hounds' heads explode when they traded Chris Paddack for Fernando Rodney during an obviously futile playoff push in 2016, but Tommy John surgery quickly made the young right-hander an afterthought. In nine starts since returning, though, he has looked like the best pitcher in the world, striking out 79 compared to just four walks in 46 1/3 innings to give him a 1.75 ERA at high A Lake Elsinore of the hitter-friendly California League. Our heads should be exploding all over again.

Nathaniel Lowe, 1B, Rays

Nobody had heard of this guy before this year, but that's kind of the point, right? When he's hitting .355 with 15 homers and a 1.035 OPS at the midway point — with plus plate discipline and ratios that are almost identical between high Class A and Double-A — it forces you to sit up and take notice. That sort of low-key dominance reminds me of Paul Goldschmidt when he was gearing up for his major-league debut. The only question is if the Rays are open to moving Jake Bauers to the outfield, where he played some in the minors.

Players who've lost the most dynasty value

It's amazing to think that just two years ago Rougned Odor was one of the most coveted assets in dynasty leagues, flashing the kind of power never before seen from a 22-year-old second baseman. But his poor plate discipline and swing-for-the-fences mentality have him so lost now that you have to wonder how much longer the Rangers will devote everyday at-bats to him, particularly with Jurickson Profar demanding playing time.

You could take a glass-half-full approach with Miguel Sano, trusting that his recent demotion to the minors will be the kick in the butt he needs, but have you actually tried shopping him in a dynasty league? Few are assigning much value to an ex-prospect with health concerns, weight concerns, maturity concerns and off-the-field concerns, not to mention a persistent inability to put the bat on the ball. It's not over, of course, at age 25, but the boom-or-bust scale is tipping decidedly toward the latter.

We had an inkling Miguel Cabrera was aging himself out of relevance, but Josh Donaldson was coming off an MVP-caliber second half and playing for a long-term deal, offering every indication he still had something left in the tank. And maybe he still does, but the very fact it's a maybe now justifies his place on this list. He wasn't setting the world on fire even before this endless battle with a calf strain, which will now sideline him for at least another three weeks, and with the injuries beginning to stack up at age 32, you're right to be asking if it's the beginning of the end.

Now five years into his big-league career, the Diamondbacks have taken to sitting Jake Lamb against lefties, giving him just 27 plate appearances. Nucleus players are supposed to get more opportunities as they develop, not fewer, which perhaps means the Diamondbacks don't consider him such anymore. As a platoon player who no longer plays half his games in a favorable hitting environment, this former All-Star thought to be in the prime of his career is quickly fading at a traditionally deep position.

Jake Junis only established himself as a dynasty asset this year, our thirst for innings-eaters so palpable that there was a time just a couple weeks ago when he would have cost you a pretty penny, especially in leagues where players are kept relative to where they were drafted. But watching him surrender 10 home runs over a four-start span is enough to sober up even his most ardent supporters. He throws strikes better than most, but the fact is he's a fly-ball pitcher with below-average strikeout potential and only one off-speed pitch. For that sort of pitcher in today's game, it's a tightrope walk. There are no guarantees here, and you've probably missed your window to sell high.