Twenty-two year old Ketel Marte is the brightest talent on an aging Mariners roster. A switch-hitter with gap power, electric speed, and great range, Marte is in line to be Seattle’s starting shortstop for the foreseeable future. It’s a competitive gig, as the bones of Brad Miller, Chris Taylor, and Nick Franklin can attest, but now that Marte’s here, he has every chance to become a franchise player. If he’s the guy who arrived in Seattle last summer, a player who knows the strike zone, mashes mistakes, and puts leather on anything hit up the middle, he’s going to be a Mariner for a long time.
But what if he isn’t?
Let’s back up a bit. In February of 2015 nobody considered Marte a budding star. He was one of the Mariners top farmhands—that and two bucks will get you a bad steak—but he wasn’t exactly drawing comparisons to Addison Russell or Francisco Lindor. Young for his level, Marte had impressed evaluators with his ability to put the bat on the ball from both sides of the plate, and even conservative scouts called him a plus runner. But he was rocky at short. His footwork was clunky, his focus drifted, and he never drew praise for his arm strength. Combined with a lack of power and a willingness to expand the zone, it was clear that Marte had holes in his game.
They were on display again in the PCL last season, even while Marte hit the snot out of Triple-A pitching. Beneath a shiny batting average, Marte was very much a developing product. He made the occasional mental error, his feet would get tangled as he ranged to his right, and everyone in the PCL knew he strode to the dish ready to swing. On one occasion, Fresno pitcher Brady Rogers was charting a game with teammate Luis Cruz. As Marte walked up for his first turn at bat, Rogers looked towards Cruz and said "I bet he swings at the first or second pitch every time he comes up tonight." It turned out to be four out of five, but close enough. While Marte wasn’t often guilty of chasing fastballs above the letters or changeups in the dirt, he rarely waited for a second offering to catch the strike zone.
It’s also worth pointing out that even as Marte thrived at the plate, the M’s weren’t sure he was ready to play shortstop at the next level. As it became increasingly obvious that his bat belonged in the majors, the Mariners brass searched for his eventual defensive home. He played a little second and was even sent to center field. As you might expect from a career infielder, he was raw, losing a couple of fly balls in the lights and running inefficient routes on drives in the gap. Despite his obvious inexperience, and even with an, ah, shaky defender entrenched at short, the Mariners still ran Marte out to center in two of his first ten big league games.
If the player described above only vaguely resembles the Ketel Marte we saw in Seattle last year, that’s no accident. In two crucial respects, Marte improved his game significantly from almost the moment he donned the blue and teal. First, he started taking walks. He walked in 7% of his plate appearances in Tacoma, which was itself an improvement over his career walk rate. In Seattle, his BB% shot up to nearly 10%, which is more impressive than it looks at first blush. Per Joe Sheehan’s newsletter from February 7th of last year, the average walk rate in Triple-A is about 19% higher than in the big leagues; Marte’s improvement isn’t unprecedented, but it’s certainly against the grain. He was also a better fielder. His actions at short looked cleaner than they were in Tacoma, and his range was a breath of fresh air following Miller’s wobbly throwing and step-and-a-dive approach to fielding grounders up the middle.
So, which Ketel Marte can the Mariners count on?
On the conservative side, it’s fair to wonder how much of his big league breakout was real. The walks in particular have a hue of fool’s gold to them. He’s never walked much before, and given how rarely players markedly improve their plate discipline numbers—it’s not like that was a strong suit of the previous player development regime, either—it feels flukey. The expanded big league strike zone neuters most hitters; Marte went the other way, and while his feel for the strike zone wasn’t a weakness, it’s unusual to see a player suddenly take pitches he recently found so alluring. It’s not impossible to develop a better sense for the strike zone, but it was odd to see the lightbulb turn on right when it did, and we should want to see more than 250 plate appearances before we call it a repeatable skill.
Marte’s defensive improvement won’t automatically carry over either. Perhaps counter-intuitively, defenders have hot and cold streaks just like hitters, and it’s certainly possible that the Mariners have already seen the best of what Marte has to offer in the field. Even with his success last summer, many evaluators still believe that his long-term future lies at the keystone.
But Marte’s situation isn’t a case where the pessimists can yell "regression!" and totter off to their local comment section. Marte was 21-years-old, and talented 21-year-olds have a knack for getting better as they grow into their adult frame. It’s fair to look at Marte’s elevated walk rate with some skepticism, but it’s also reasonable to mention that his contact profile doesn’t have any red flags. He didn’t chase junk out of the zone. He looked at more pitches than your average big leaguer. He laid off pitcher’s pitches. When he swung, he made a lot of contact. Those are all good things.
That discerning eye feeds well into the rest of his game. He hit .283/.351/.402 last summer, and while you can lift an eyebrow at the totals, the numbers aren’t obviously unsustainable. Yes, he had a high BABIP, but a .345 figure isn’t outrageous for a switch-hitter who makes a lot of contact, particularly for a player who excels in part by hitting grounders and running like hell. It’s tempting to say that he won’t hit for as much power as he did last year but again, he was just 21: he’s only going to get stronger and become more comfortable facing big league pitching. If his offense were to actually improve, and if he demonstrates that he can handle short, the club would clearly have a star on its hands.
So, will the Mariners get the flawed-but-talented Marte, or the building block he looked like last summer? A fair assessment of his profile and recent production finds roughly equal merit in both options. As is often true in such cases, the answer likely lies in the middle. Realistically, Marte’s power and plate discipline numbers will go backward. His UZR will probably not shine as brightly as it did in last summer’s brief sample. Fewer grounders will find holes. Opposing catchers may even throw him out.
But most guys who succeed at Marte’s age do so because they’re really good. Eighty-five percent of 2015 Ketel Marte is one heck of a ballplayer, and even evaluators who are down on his skillset would have to concede that he’s not a finished product. Ultimately, Marte is a legitimate breakout candidate, and if he’s anything like the player he was last summer, he could help shift the power dynamic in the AL West.