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Just as Greg Wellemeyer did in looking at two catching prospects and two second-sackers, I’m back to offer an in-depth look at a pair of prospects at the hot corner as a companion to Bret Sayre’s dynasty-oriented look at the position, in the same format as I did in looking at our first-base matchup of Trey Mancini vs. Bobby Bradley. We hope that you’re enjoying the series, as it’s aimed at helping dynasty-league owners in the decision-making process that quite often occurs when trying to differentiate between two prospects, whether it be during draft time or in trade talks.

Today, we take a look at the top two prospects on Bret’s third-base rankings (and two very popular trade targets in dynasty leagues this offseason), the Red Sox' Rafael Devers, who checked in at no. 11 and Rockies farmhand Ryan McMahon, who was ranked at no. 16 by our fearless fantasy overlord.

Batting Average
Devers, then 17, hit for a sparkling .322 batting average in his first 302 plate appearances as a professional, split between the Dominican Summer League and the Red Sox' Gulf Coast League affiliate in 2014. He moved up to the South Atlantic League in 2015, where he hit .288 in his first taste of full-season action over 508 plate appearances–good for 18th in the league and the fourth-highest mark by a teenager.

McMahon owns a lifetime .297 batting average as a professional, with all three of his seasons coming in favorable home hitting environments; first at Rookie-level Grand Junction of the Pioneer League in his draft year of 2013, where he hit .321, and then at Low-A Asheville, where he hit .282 in 552 plate appearances in 2014 before moving on the various bandboxes of the California League in 2015 and hit for a .300 average with Modesto in 556 plate appearances. In Grand Junction and Modesto, McMahon’s BABIP hovered around .400.

Devers was issued a 60 grade for his hit tool by former Prospect Team member Tucker Blair early in the 2015 season, and McMahon was given a 55-grade hit tool by Wilson Karaman in his multiple viewings during Cal League action in 2015.
Advantage: Devers

On-Base Percentage
Devers walked a reasonable 35 times in short-season ball, a rate of 11.6 percent, before showing a complete aversion to walks in Low-A ball, where he walked just 24 times all season. His walk rate of 4.7 percent was the 13th-worst in the league among hitters who received 300 or more plate appearances. As a prospect playing in his age-18 season, it’s certainly far too early to write off Devers as a hacker with no plate discipline, but it’s hard to see that low of a walk rate and not be at least a little concerned.

McMahon hasn’t exactly been a master of patience in his young professional career either, walking in just under 9 percent of his plate appearances in 2015. In 2014, he did walk more than twice as often as Devers did while playing in the South Atlantic League, with the caveat that the Rockies prospect was a year older than Devers while playing at the level.
Advantage: McMahon

Home Runs
Devers was given $1.5 million to sign by the Red Sox in 2013 largely based on his power potential, and while most feel comfortable giving him a plus-plus raw-power grade, the monster power hasn’t manifested itself in games to this point in his young career, as Devers hit 11 home runs over 115 games in 2015. His 38 doubles were the second most in the league, and he was the only teenager in the top 10.

McMahon is also more of a doubles hitter at this point in his career, although his 18 home runs in the Cal League in 2015 did place him among the top-10 in the league. His 43 doubles were most in the league, and it marked the second consecutive season where McMahon clubbed 18 home runs (in almost the same amount of plate appearances).

Advantage: Devers

Stolen Bases
Devers stole three bases in five attempts in 2015. McMahon, a former quarterback at a high school (Mater Dei, in Orange County, CA) that is known for producing them in droves, certainly has the athleticism to steal bases, but he simply hasn’t done so at an adequate rate as a professional–evidenced by his six successful stolen bases in 19 attempts in 2015. It’s probably not a good idea to expect either of these guys to add much value with their legs as they mature.
Advantage: McMahon, very slightly

Other than some less than flattering references to Devers’ future waistline, my exhaustive research was unable to turn anything up regarding a current nickname for the Red Sox prospect. McMahon did not disclose a nickname to the Grand Junction Daily Sentinel in 2013 when asked, but did reference a love for beach volleyball and presumably long, romantic walks after. No nicknames have surfaced since then, at least that I could find.
Advantage: Neither, Disappointingly

Injury Risk
Other than a minor stress fracture in Devers’ foot suffered during instructional work in 2014, there have been no notable injuries for either player.
Advantage: Neither

Both Devers and McMahon feature intriguing potential with the bat, but they also both could be moved off of third base–even before reaching the majors. For me, Devers is the more likely of the two to be moved, as his body could simply outgrow the position as he matures. McMahon could be moved off of the position due to the Rockies already having a pretty damn good third baseman in Nolan Arenado, who has already established himself as one of the league’s best (no. 4 on Bret’s rankings), despite being just about three and a half years older.

Devers’ potential with the bat could be that of a batter who hits for close to a .300 average with a home run total in the neighborhood of 35 and plies his trade in the middle of a productive Red Sox order in a ballpark (and division) that is conducive to his power. McMahon’s upside is likely more of a .280-ish hitter with 20-25 home runs, a better play in OBP leagues who sees his runs-scored and RBI totals boosted by his home ballpark. While Devers’ walk-rate was a concern in 2015, McMahon’s strikeout rate of 27.5 percent in High-A ball could portend trouble as he faces more advanced pitching at Double-A Hartford in 2016. If it creeps up too much further north, his lifetime OBP of .372 will almost certainly come down.
Risk: McMahon, Upside: Devers

Estimated Time of Impact
As was touched on earlier, Devers played the 2015 season as an 18-year-old in his first full professional campaign. The Red Sox have little reason to rush Devers to the big leagues and he likely won’t see Fenway until sometime in 2018 at the earliest; I feel that mid-2019 is a far likelier scenario. McMahon will reach Double-A in 2016, but with Colorado’s historical tendency to conservatively move prospects up the ladder–and the presence of Arenado–it’s hard for me to envision McMahon seeing the majors in any role in 2016, with mid-2017 or early-2018 as more realistic timeframes.
Advantage: McMahon

Give me McMahon between the two, as I think it’s entirely possible that Devers moves to first base before he reaches the majors and doesn’t quite reach his 35-40 home run potential–“only” hitting 25-30 per season.

While I certainly acknowledge the possibility that the Rockies could offer Arenado a large contract extension and keep him after his team control expires after the 2019 season, I believe that trading Arenado prior to his free agency (and sooner than later for that matter) represents Colorado’s best chance to import the quality pitching needed to once again be relevant in a very competitive National League West. It’s obviously very hard to decipher what the Rockies' plans are–in both the short and long-term–but I haven’t gotten the impression that the Rockies ownership has been thrilled with the large contracts that were given out to players like Troy Tulowitzki and Carlos Gonzalez over the years, and even franchise icon Todd Helton to an extent, and they may not want to put themselves in the same position with Arenado, who isn’t likely to sign for anything that resembles a hometown discount with Scott Boras as his agent.

A trade of Arenado is viewed as an unlikely proposition as of now, but by the time McMahon is ready, it could be viewed as a likelier scenario, and I think that should be accounted for when discussing McMahon’s dynasty value, just as a possible move to another position in order to accommodate Arenado currently is. If McMahon ends up being the one traded for pitching help, I still feel that he can be a top-10 option at the position, even without the Coors Effect(™).
And the winner is… McMahon.

Thank you for reading

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Clearly, Ryan McMahon's nickname should be "Ice", like Ice McMahon, which is kinda like "Iceman" which recalls the beach volleyball scene in Top Gun.

Also, this made me feel much better about dealing for McMahon in recent days.
I like where you're headed with this. I considered all types of Jim/Vince McMahon references, but yours is much better.
With absolutely no justification for my opinion, I'm going to say that this is horse crap and Devers is leaps and bounds better to own in a dynasty league. So there.
I like your moxie