Astros Power Arm Martes Emerges as Top Prospect

Astros right hander Francis Martes started the year in extended spring training and Kiley McDaniel had him graded as a 35+ FV. Martes was one of the lesser pieces in the big Jarred Cosart/Colin Moran trade and he was in Rookie-level ball at the time of the trade. From last year to early in 2015, Martes’ velocity jumped, his breaking ball jumped from fringy to at least plus, all of which has helped his above-average changeup play even better. Last week, Kiley graded Martes as the top prospect in the minor leagues that wasn’t in his pre-season Top 200, falling somewhere among the top-50 prospects in baseball and earning at 55 FV grade.

Martes went out to Low-A from extended spring this year, then to the hitter-friendly High-A Cal League where he dominated again until the 19-year-old scorching hot prospect got the promotion to Double-A on Monday. Here’s my observations from two looks at Martes earlier this year in extended spring training, in April/May when his whirlwind season was just getting started and very few scouts were paying attention.

Physical Description

Listed at 6-foot-1 and 225 pounds, Martes’ listed height and weight appear fairly accurate. Martes has a thick, stocky build. He is barrel chested, with an exceptional amount of natural strength through his upper and lower body. He will have to keep an eye on his weight moving forward. There is minimal projection for any good growth remaining, as Martes is likely close to being physically maxed-out.

Fastball: 65/70

Previously a low-90s offering that scraped the mid-90s, Martes has added velocity once again this off-season. His fastball now sits comfortably between 95-97 mph, almost never dipping below 93 and topping out as high as 98 mph. The fastball jumps at hitters when he maintains full extension out front, making it appear even faster than its already near elite velocity. Additionally, the fastball features wicked late life, making it often difficult to barrel. He also maintains his velocity exceptionally well throughout starts. Martes still needs the expected work on consistent fastball command, but the pitch flashes elite potential that will challenge batters at the highest level.

Curveball: 60/70

Thrown with elite velocity, Martes’ 83-84 mph breaking ball is absolutely nasty. Martes stays on top of it, getting consistent tight rotation. There is excellent depth and sharp late-breaking action on the pitch. Even the rare cement mixer (breaker with lesser bite) is an above-average weapon. Martes appears comfortable throwing it as both a chase pitch and sneaking it in the zone for strikes. He will occasionally backdoor the pitch in the strike zone to break up predictable sequencing. He commands the offering exceptionally well. Martes’ breaking ball is a nasty swing-and-miss offering that will quite simply torment batters at the highest level.


A reaspectable third offering, Martes’ changeup sits comfortably between 88-89 mph. The changepiece plays well off the fastball, keeping hitters off-balance and guessing. Martes has a feel for the offering, maintaining arm speed to sell the pitch, giving it legit swing-and-miss potential moving forward. It features average downward dive with occasional fade at its best. Overall, the changeup is a projectable offering with solid MLB average potential.

Command: 45/50

Despite having electric velocity and being just 19 years old, the profile already features a respectable amount of control and command. Martes challenges the opposition, routinely getting ahead in the count by throwing quality strikes. He utilizes his entire repertoire, sequencing well to avoid predictable patterns and pitching backwards, throwing secondary pitches when behind in the count, to keep the opposition guessing. Martes’ profile currently has a chance for above-average control and command, but it’s still early in his development and these types of power pitches usually end up with the control a notch ahead of the command — or, at least early in their careers.


Martes delivers the ball from a standard 3/4 arm-slot. The delivery is almost effortless with clean and quick arm action through the release point. His arm slot generates solid natural downward plane to the plate. Martes is an exceptional athlete, although I suppose you have to be though to replicate his rather unorthodox delivery. Taking ingredients from Luis Tiant, Johnny Cueto and Anibal Sanchez, Martes’ delivery features many moving parts, yielding a great deal of deception. After beginning his windup with his hands high above and behind his head, Martes steps back towards first-base with his front foot, before elevating his leg into a high tuck. Although it’s not as exaggerated as some of the above-mentioned names, Martes will then occasionally rotate his torso until he’s facing third base, at which point he uncoils and delivers the ball to the plate.

Similar to Jose Valverde, Martes finishes hard, rotating his hip and landing aggressively to the first-base side of the rubber. Despite having so many moving parts, Martes repeats his delivery and landings exceptionally well. Regardless of the offering thrown, Martes does a great job maintaining his arm slot and arm speed. He fields his position and holds runners exceptionally well, delivering the ball to the plate from the stretch rather quickly, typically between 1.2-to-1.3 seconds.


The term bulldog is thrown around too frequently in the baseball world; however, Martes fully embodies the attributes of a bulldog with his aggressive mound presence. “Controlled anger and chaos” is perhaps the best way to describe Martes’ demeanor. He owns the mound, often psyching out opposing batters with his electric velocity and advanced command. Despite his angry and aggressive demeanor, Martes is approachable. He enjoys the game of baseball and he has strong desire to succeed at the big-league level. Martes is highly regarded by his teammates and coaching staff as a hard worker and a great teammate. He responds well to constructive criticism and has shown the aptitude to polish his craft. There are no off-the-field issues, or potential red flags, as Martes features solid makeup.


A relatively unknown name coming into this season, Martes is now a top-100 prospect. When I first took an interest in amateur scouting, I remember asking my mentor how I’d know when a potential prospect had “it” — the ingredients of a potential difference-making star. Aside from the various attributes one might find in the scouting handbook, my mentor offered these words: “You just know. You immediately want to write the report and the report writes itself. You feel as if you’ve found something special and you can’t wait to tell everyone about it.” Francis Martes embodies all of what my mentor said quantifies as having “it.”

The fastball and curveball could challenge batters at the highest level right now, and the changeup isn’t too far behind. As far as a timeline is concerned, Martes is probably a year away from contributing at the big-league level. Overall, I’m bullish on Martes and I see a potential frontline starter should he stick in the rotation. There have been whispers of Martes potentially moving to the bullpen; should that happen, I see the entire profile playing up, yielding an elite top-tier closer. Not too shabby, especially when you consider the fact that Martes was essentially the “throw-in/project” from Miami in the Jarred Cosart trade.

James Chipman is a prospect writer for FanGraphs, The Detroit News and A resident of Orlando, FL, he frequently views prospects in the Florida State League, Gulf Coast League as well as Grapefruit League and Extended Spring Training. He can be followed on Twitter: @J__Chipman.

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8 years ago

Nicely done, Mr. Chipman, and welcome to FanGraphs.