The Seattle Mariners obtained right-hander Luis Castillo from the Cincinnati Reds on Friday night in the first major move ahead of Major League Baseball's Aug. 2 trade deadline. In exchange, the Mariners sent four prospects to Cincinnati: shortstops Noelvi Marte and Edwin Arroyo and right-handers Levi Stoudt and Andrew Moore.

The Mariners, currently the American League's second wild card team, are attempting to make the postseason for the first time since 2001. Castillo should reinforce a rotation -- both this season and next -- that already includes reigning Cy Young Award winner Robbie Ray and quality youngsters Logan Gilbert and George Kirby. His addition comes at a steep prospect cost for the Mariners, but that goes to show how serious top exec Jerry Dipoto is about snapping the sport's longest playoff drought.

On the Cincinnati side of things, Castillo's departure is the latest (albeit not the last) part of an ongoing rebuild that dates back to last winter. The Reds are in full talent accumulation mode at this point, and it's fair to write that they netted a handsome return for their ace and his season and a half of remaining team control.

We here at CBS Sports are nothing if not judgmental, and that means offering near-instant analysis on big trades this time of the year. Below, you'll find "grades" for both the Mariners and the Reds, along with explanations for those assessments. 

With that out of the way, let's begin by recapping the deal:

Mariners receive

  • RHP Luis Castillo

Reds receive

  • SS Noelvi Marte

  • SS Edwin Arroyo

  • RHP Levi Stoudt

  • RHP Andrew Moore

Mariners grade: A

This is the kind of trade you make when you haven't made the playoffs in more than two decades. Seriously, though, this is a welcomed sight in a few respects, beginning with how it rewards a passionate (and tormented) Seattle fan base and extending to how it runs counterculture to the league as a whole. 

Teams are far too happy these days to take a postseason berth for granted. Their executives will make a marginal upgrade or two on the margins. If the chips fall as they may and it's enough to get into the playoffs, great; otherwise, why risk losing out on some sweet, sweet surplus value for anything less than a division title?

The Mariners are not going to win the AL West. They'll enter Saturday as far behind the Houston Astros as the San Diego Padres are the Los Angeles Dodgers. Adding Castillo does shore up their postseason odds, and, more importantly, it makes them a more dangerous October opponent. 

Keep in mind, the new playoff format does away with the one-and-done Wild Card Game; the top two seeds in each league will get a bye while the others play a best-of-three series at the better team's stadium. The Mariners now have a better chance at hosting that series and can trot out a three-game rotation that includes Castillo, the reigning Cy Young Award winner, and Logan Gilbert, one of the most promising young starters in the sport. That's a tough set of match-ups for the Toronto Blue Jays or any other team looking to sail onward.

Presuming that the outgoing package, as good as it is, would not have been enough to net either Juan Soto or Shohei Ohtani, then Castillo was the most impactful player the Mariners could have gotten back. To wit, the 29-year-old Castillo may well get the Game 1 assignment. After missing the start of the season because of shoulder woes, he's recovered to post a 2.86 ERA (160 ERA+) and a 3.21 strikeout-to-walk ratio in 14 starts. Since the start of the Pandemic Era, he ranks seventh in Wins Above Replacement among starters. He's under team control through the end of next season, too, and despite the aforementioned shoulder problem, he's made a full slate of starts every year dating back to 2018. The Mariners should feel optimistic that Castillo can provide them with a lot of quality starts between now and winter 2023.

Castillo's signature pitch is his changeup. It's one of, if not the best of its kind and he's often used it as his primary offering throughout his career. Yet Castillo's cambio hasn't been his attention-grabbing pitch so far this season; that honor instead goes to his four-seam fastball, which has averaged 97 mph and has generated a .125 batting average-against and a 38.7 percent whiff rate, the highest among pitchers with at least 300 four-seamers thrown to date. Castillo also sinks his fastball and throws a slider, but for our money, it's the four-seamer and changeup that makes him good.

Most people would have agreed entering Friday morning that it would be great to see the Mariners make a splash and that Castillo was the best pitcher on the market. Now that the cost is known, there's likely to be some disagreement now on whether or not this trade was worth whatever comes next. It was a lot to give up, no doubt, and this trade will limit Seattle's ability to make further moves, this summer and heading forward. Castillo's addition could end up being the difference between the Mariners winning a playoff series (or more) and not.

We're giving the Mariners an A because we think teams -- particularly those who aren't the usual suspects -- prioritizing the potential for deep playoff runs is healthier for the sport, and because we quite like Castillo as a pitcher. We would understand anyone giving them a worse mark because of the sheer amount of talent they gave up for a relatively short-term fix.

Reds grade: A

It's become vogue for struggling teams to hit the reset button by trading every player who is either nearing free agency or banking seven-plus figures. There's no easier way for a general manager to carve out additional job security than invoking a five-year rebuild plan. That way, the owner saves oodles of money and the exec doesn't have to deliver results. Just trust the process, man. Skepticism bordering on cynicism is warranted whenever a team embarks down that path. 

The worst, most craven of these situations -- the ones where the clear goal is to save the owner some money at the expense of the team -- look a lot like what the Reds did over the offseason. They rushed to dump catcher Tucker Barnhart for a non-prospect and they surrendered lefty Wade Miley on waivers to the Chicago Cubs. Both moves were inexplicable, even at the time, and suggested the Reds would be taking the long, hard, cheap road back to relevancy. (It didn't help matters that the owner's son, a replacement-level suit, mouthed off toward fans early in the season.) This trade, on the other hand, is rebuilding done right. 

The Reds extracted the two best prospects from a good Seattle farm system in exchange for a year and a half of Castillo in a market-setting deal that feels ripped from the past. Teams these days generally do not recoup this much prospect capital for pitchers who are so close to free agency. Factor in Cincinnati's selection of Cam Collier in the draft, easily the best value in the first round, and the Reds have added three high-grade position player prospects to their farm system in a matter of weeks.

Granted, it's never easy to trade a pitcher of Castillo's caliber, especially when he stands out as one of the franchise's biggest recent scouting and development wins. (The Reds acquired Castillo from the Miami Marlins in 2017 for Dan Straily; Castillo made 137 starts for the Reds thereafter, as compared to Straily's 56 with the Fish.) Doing so now, and for this return, is a defensible baseball decision on multiple levels. 

Castillo, though largely durable throughout his career, did miss the start of the season because of shoulder woes. His looming free agency means the Reds needed to make a call, either extending or trading him; the former felt like a dubious decision given the Reds' placement on the win curve and the risks associated with giving a veteran starter -- even a very good one -- a long-term contract worth their market value.

Marte, 20, entered the spring ranked by CBS Sports as the sport's 11th best prospect. He's spent the year in High-A, where he's faced competition that is on average close to three years his senior. That hasn't stopped him from batting .275/.363/.462 or tallying 34 extra-base hits (including 15 home runs) and 13 stolen bases in 85 games. 

Marte combines big raw power with a feel for contact and for the zone. He's never struck out in more than 22 percent of his plate appearances over a full season, yet he's reliably worked walks in at least nine percent of his trips to the plate. If there is an area of concern with his offensive game, it has to do with his propensity for wearing out left field. His 55 percent pull rate would rank as the third-highest in the majors, behind only Daulton Varsho and Byron Buxton. The Reds may work with Marte on using the whole field so he's tougher to defend, or they may conclude that there's no defense for him clearing the wall; either way, he has enough working in his favor tools- and performance-wise to think he'll develop into an above-average hitter.

The biggest drawback with Marte is his defense. He made 30 errors in 99 games last season, and he's already up to 24 mistakes in 81 contests this year. The Reds will likely task their instructors to work with him on his internal clock and smoothing his rough edges, as there's no physical reason he can't improve at the six. Should that fail to take, he'll likely have to slide over to third base. Marte's bat gives him a wide berth, and it's possible he develops into a star-caliber player regardless of where he stands.

Arroyo, 18, had his fans in the 2021 draft because of his combination of youth (he won't turn 19 until late August) and defensive polish. He's a no-doubt shortstop who has the hands, feet, and arm to be an asset at the position for the long haul. The question mark with his game has been his bat, but he's a switch-hitter who has held his own despite being significantly younger than his competition in his first full professional season. Indeed, Arroyo led a team that included well-regarded prospects like Harry Ford and Jonatan Clase in hitting by batting .316/.385/.514. That bodes well. 

Arroyo's glove gives him a high floor. If he continues to progress as a hitter, the Reds will have landed two starting-caliber left-side infielders in a single trade. 

Stoudt, 24, is a small right-hander who is positioned to be the first member of the package to reach the majors. He's already appeared in 21 games at the Double-A level, albeit to less-than-optimal results. This season, he compiled a 5.28 ERA in 87 innings, with much of that damage owed to one of the higher home-run rates on his club. Stoudt has better stuff than those marks indicate, including a mid-90s fastball, but there's a better-than-fair chance he ends up pitching in relief as a big-leaguer.

Moore, 22, should not be confused with the former Mariners pitcher of the same name. Whereas the other Moore was a command-and-control starter prospect, this Moore is a pure reliever who pumps gas with a mid-to-upper 90s fastball. He struck out 58 of the 133 batters (44 percent) he faced with the Mariners this season. He could occupy a high-leverage role if he can continue to throw strikes at an acceptable level.

The Reds, who also dealt outfielder Tyler Naquin earlier this week to the New York Mets, should remain active on the trade front between now and Tuesday's deadline. Industry sources have informed CBS Sports to expect the Reds to move right-hander Tyler Mahle and resurgent utility infielder Brandon Drury before the buzzer sounds.