Sometimes it takes players a little longer than others to find their stroke. In 2015, MLB Pipeline rated J.P. Crawford the 5th best prospect in the game. He was considered the best defensive infield blue-chipper in baseball with a 60-grade arm and even more impressive 65-fielding tool.

The defense is beginning to show its legs at the big league level. Crawford appears poised to cement himself this season as one of the better defensive shortstops in pro ball.

That being said, it’s Crawford’s bat that will need to pop if the Mariners are to lock him in as the shortstop of the future. After all, Javier Baez, Trevor Story, Corey Seager, Carlos Correa and Francisco Lindor are all positioned to become free agents after the 2021 campaign. Furthermore, Marcus Semien is slated to hit the open market after 2020. With money to burn, Jerry Dipoto’s itch will be primed and ready to scratch.

Crawford, now 25, likely has all of 2020 and 2021 to prove his bat can provide enough value to staple himself into the Mariners’ next competitive window.

After an already impressive May, June saw Crawford run a slash of .338/.413/.569 with a 161 wRC+. He had nine extra base hits, walked 12 percent of his at-bats and struck out less than 18 percent of the time. Crawford has always had an advanced approach at the plate, garnering plenty of walks and posting above average strikeout numbers.

It was all coming together. Crawford had turned the corner. On June 26, he was pacing a 5.8 fWAR/600 ABs — a figure that would have very comfortably placed him inside the top five shortstops in the league for an entire season. Crawford had over a month and a half of remarkable production under his belt, but it didn’t last.

His offensive game cratered a bit after that, failing to post a wRC+ over 70 during any other month. That being said, Crawford had already flashed what he was capable of. If he can become just 80 percent of the player he was from May through June over the course of an entire season, he’s a 110 wRC+ shortstop and being mentioned among the likes of Lindor (114 wRC+), Baez (114 wRC+) and Seager (113 wRC+).

Although he’s played in portions of three big league seasons, Crawford has only accrued 621 big league at-bats. In those abbreviated stints, he’s posted 2.1 fWAR. Let’s take a look at how some other notable 2015 top shortstop prospects fared in their first 650 at-bats.

What do all these players have in common? All six, with the exception of Crawford, have now posted campaigns with a wRC+ of 110 and 2.8 fWAR or better. It could be a matter of time.

Players like Seager, Lindor, Ozzie Albies and Alex Bregman were top prospects in 2015 as well, and it certainly clicked for them a lot quicker than others. And for as many guys that blew up, there’s always going to be those that fizzle out. Other top shortstop prospects from 2015 like Orlando Arcia, Franklin Barreto, and Javier Guerra haven’t yet been able to forge their status at the big league level. But as the numbers show, sometimes it can take time for guys to grow into their future profile.

So why are we to believe Crawford is on the precipice of a breakthrough? For one, Crawford is still younger than everyone on that list, with the exception of Adames and Moncada. But more importantly, after some drastic pre-2019 swing adjustments, he should be in a much better place to produce. In short, his mechanics were an absolute mess.

Take this for example from 2017.

The biggest take away here is there’s so many moving parts. Crawford is just about dead in the water before the ball even leaves the pitchers hand. His hands are incredibly high mid-stride, and still moving up and toward the pitcher as he’s preparing the anchor his plant foot. With the foot down and the hands still back, they’re forced to lag behind. Hell, the bat is almost perpendicular to the body by the time he’s looking to explode through the ball. The hips are already opening well-before the hands are afforded the opportunity to drop into a good slot. The result is a swing with very little leverage, loft, and tons of lost torque through the ball. It’s all arms and very little core, subsequently creating a loopy swing. That loopy swing was one of the reported reasons Philadelphia was willing to move him for Jean Segura pre-2019.

Here’s another:

This, from last July. After a fantastic start to the season, Crawford begins to drift back into bad habits. You can see the hands creep up, away from the ball, as the pitch is being released, rather than dropping into a lower, more aggressive slot. They’re simply moving in the wrong direction. The bat flattens out, and again, the swing becomes loopy as he’s unable to keep his hands inside.

But as mentioned previously, there were times last year where Crawford’s swing looked sound and incredibly powerful for his size. He creates pretty good bat speed for a guy of his build. Crawford mentioned last season that he had worked hard on the net drill Robinson Cano was so famous for. The drill is simple; place a net on the outside part of plate, and don’t touch it during your swing. It allows the player to keep his hands inside and explode through the ball, torching balls on the inner-third of the plate. Here’s a great example of that.

The hands stay inside, allowing Crawford to turn and burn on a pitch middle-in. The pre-swing mechanics still aren’t perfect, as the bat still lays pretty flat across his shoulders, but it’s a lot cleaner. Keeping his hands back further than conventional thinking may be how Crawford ends up tapping into the power he naturally lacks from his size. He creates a ton of torque and rotation with his size, good for upping his bat speed. But as mentioned above that has to come within the confines of a good timing mechanism and mechanics. In this example, it works. The foot gets down, the hips wait for the hands, and the hands stay inside allowing for good loft and explosion through the ball.

This, really, is the penultimate example of what Crawford could be. The hands, hips, and plant foot are in lockstep allowing a ton of force behind the swing. The hands are quiet and set, and drop into a good slot as he loads into his core. Again, it’s not perfect, but this may be how Crawford accesses the best version of his in-game power.

This ball left the bat at over 105 mph and traveled into the second deck of Citizens Bank Park, still among the hardest balls he’s ever hit. Crawford ranks among the bottom of the league in exit velocity and barrel percentage, but for my money, those figures are beguiling and possibly a result of some truly jumbled mechanics.

Crawford’s exit velocities dipped over the course of the season. In May and June, Crawford had an estimated fly ball distance of just 250 feet, but posted a strong line drive percentage. It’s worth noting, luck was on his side too, producing a BABIP of .396. His 36 percent fly ball percentage (FB%) over that time was healthy as well. He was driving the ball with authority.

This drastically changed over the course of the rest of the season as his mechanics and health took turns deteriorating. From July through September, Crawford averaged over 300 feet in estimated fly ball distance, but his BABIP plummeted, bottoming out at .161 over final 20 games of the season. His FB% dropped to under 30 percent, and his ground balls spiked, peaking at over 55 percent during one particularly dreadful 30-game stretch.

Simply put, Crawford is an extreme example of being a product of your mechanics. If the swing is clean, Crawford has the ability on the diamond to become an all-star type middle-infielder. If the hands and swing get lazy, he’ll have a difficult time posting anything close to what he’s capable of.

Crawford will be a very interesting player to watch during spring training and early on this season. He’s been very vocal in his desire to win a Gold Glove in 2020, but it’s his bat that will truly make or break his future value to the organization. It’s not hard to foresee a .275/.350/.470 hitter in there.

Time will tell.