In many ways, the Fernando Tatis Jr. we’ve seen in 2020 is the same awesome player he was as a rookie. The power. The speed. The rocket arm. The tools have all been there. But Tatis is also different -- and better -- in one key area.

At age 21, with fewer than 450 big league plate appearances under his belt, the Padres' shortstop is already showing signs of becoming a more polished and disciplined hitter. And that should be a scary thought for the rest of the league.

Granted, he’s still striking out a ton like he did in 2019, but that didn't stop him from hitting .291/.391/.673 over his first 14 games this season. His xwOBA through Thursday was a terrific .385, up from .357 last season, and he slugged a leadoff homer on the first pitch in the bottom of the first inning Friday against the D-backs for his fifth round-tripper of the year.

Here’s what he’s done to improve, and why it matters. (All stats below are through Thursday.)

He’s laying off bad pitches

While it’s much easier said than done, knowing which pitches to swing at and which to take is one of the fundamental aspects separating good hitters from poor ones.

As is the case with many young hitters, Tatis saw a lot of pitches out of the zone last season, as pitchers tried to take advantage of his aggressiveness. Of all the pitches he saw, 56.2% came outside the strike zone, which was tied for the 17th-highest mark in MLB (min. 1,000 pitches).

Tatis acquitted himself fairly well on these offerings, as his 29.8% chase rate wasn’t much higher than the league average (28.8%). That said, the shortstop wasn’t doing himself any favors by chasing nearly 30% of the time, as he hit just .112 with a .131 slugging percentage in at-bats that ended on a pitch outside the zone. He also walked in only 8.1% of his plate appearances overall.

Tatis was especially susceptible to swinging at pitches down and away. Of the 786 pitches he saw outside the zone, 406 of them were down and away, and his chase rate on such pitches was 32.3%. He struck out 34 times and didn’t have a single extra-base hit on down-and-away pitches out of the zone.

In 2020, Tatis has looked like a completely different hitter in this regard. The youngster’s chase rate this year is just 14.2%, which is better than that of Reds first baseman Joey Votto (16.5%), a player renowned for his plate discipline and command of the strike zone. On down-and-away pitches out of the zone, Tatis’ chase rate is 18.2%.

Tatis is also making contact less when he does chase. While less contact might seem like a negative, consider that he put 47 balls in play on his 234 swings on pitches out of the zone last season and just two of them resulted in extra-base hits (both doubles).

This year, he has put only one ball in play when swinging at pitches outside the zone, which has meant longer at-bats, more walks (15% walk rate in 2020) and a higher percentage of his batted balls coming off in-zone pitches. That's a big deal, because ...

Few destroy in-zone pitches like Tatis

The extent to which Tatis has excelled on in-zone pitches during his brief MLB career is staggering, as he has posted the highest slugging percentage in MLB on these pitches since the beginning of 2019.

Highest SLG on in-zone pitches, since 2019
Min. 200 at-bats ending on in-zone pitches
1. Fernando Tatis Jr. -- .806
2. Yordan Alvarez -- .789
3. Nelson Cruz -- .780
4. Carlos Correa -- .774
5. Miguel Sanó -- .765

Some of that is due to luck, as Tatis’ lifetime xSLG on pitches in the zone is over 130 points lower, but a .670 xSLG in said situations is still outstanding, and he has managed to record a barrel -- batted balls with the ideal combination of exit velocity and launch angle for producing extra-base hits and homers -- on 16.7% of his batted balls coming on pitches in the zone, tied for 14th in MLB since the outset of 2019.

While his chase rate has dropped considerably, Tatis has remained aggressive when he sees something he likes. His swing rate on in-zone pitches this year is 66.1%, after he had a 70.5% mark as a rookie.

Tatis also has swung 36.7% of the time on the first pitch, up from 35.8% last season. In his career, he owns a .918 slugging percentage on first-pitch batted balls, with eight home runs in 61 at-bats ending on the first pitch.

Whatever Tatis is doing this season, it’s obviously working quite well. He has the highest hard-hit (batted balls with 95+ mph exit velocity) rate in MLB (min. 25 batted balls) at 66.7% and is tied for third in total hard-hit balls.

Hard-hit balls, 2020
1. Corey Seager -- 28
2. Salvador Perez -- 21
3-T. Fernando Tatis Jr. -- 20
3-T. José Abreu -- 20
5-T. Christian Walker -- 19
5-T. Eloy Jiménez -- 19
5-T. Tommy Pham -- 19

What about his strikeout rate?

Although Tatis’ plate discipline has improved, his strikeout rate has spiked to 35%, from 29.6% in 2019.

However, his K-rate has been inflated by his somewhat flukish seven strikeouts looking in 13 games, after he had 23 such K’s in 84 games last season. Of these seven strikeouts looking, two were borderline calls at the knees, and one was well off the plate inside.

While the shortstop is certainly still prone to swinging and missing when pitchers get two strikes on him, his K-rate will likely drop some moving forward.

And even if he continues to strike out at a 30% clip, his ability to mash balls in the zone, coupled with his newfound plate discipline, should keep the dynamic 21-year-old among the game’s most destructive hitters.

Plus, given the advancements he's already made so early in his career, who's to say there won't be more to come?