Analyzing Fernando Tatis Jr.‘s Breakout
Fernando Tatis Jr. has certainly made a name for himself. Often when a minor league prospect has a former MLB father, that player ends up over-hyped. In Fernando Tatis Jr’s case, he may have been under-hyped. What he has done in his short time in the majors is nothing short of amazing. The question now is: can he keep this elite level of production up and live up to the massive 14 year, $340M contract he signed this past month? Let’s dive in and see.
Since he broke into the league in 2019 as a 20-year-old top 3 prospect, baseballs haven’t been safe around Tatis. In his rookie campaign, he slashed a mighty .317/.379/.590, good for a 150 Weighted Runs Created Plus (wRC+); with 22 home runs and 16 stolen bases in only 84 games. Not too shabby for any player, never mind a rookie not even old enough to buy a legal beer to celebrate. Rather than fall into the dreaded sophomore slump, he doubled down on that production with a .277/.366/.571 triple slash resulting in a 149 wRC+. That 2020 production does not even paint the complete picture of just how much he improved.
In 2019, Tatis hit the cover off the ball with a 90.4 mph average exit velocity, 13.2% barrel rate, and 44.1% hard-hit rate, which are all way above average. His only glaring weakness was how often he swung and missed, evidenced by his 35.2% whiff rate and 29.6% strikeout rate, which were also well above league average. This lead to a much lower .256 expected batting average (xBA) and .489 expected slugging percentage (xSLG). Couple that with an unsustainably high .410 batting average on balls in play (BABIP), that exposes there was some luck involved to go along with the elite talent.
In 2020, Tatis took a huge step forward. He cut his whiff rate by 7.2% which lead to a much more palatable 23.7% strikeout rate. Couple that with an out-of-this-world average exit velocity of 95.9 mph, 19.5% barrel rate, and a hard-hit rate of 62.2% — all three of which were the best marks in the majors — and you have a very scary hitter.
Just exactly how did Tatis go about cutting his whiff rate? Well, he became more selective and made more contact on pitches out of the zone. In 2019, pitchers got him to chase 29.9% of the time. On those swings, he only made contact on 42.1% of them. In 2020, he was able to lay off a few more of those pitches, swinging at 26.1% of them but the real improvement came from how much contact he made on those swings. He bumped his chase contact rate up to a slightly higher than league average of 60%. This change not only helped him lower his strikeout rate but also bumped his walk rate up from a roughly league-average 8.1% to a higher-end 10.5%.
All in all, this led to much better expected statistics and actually shows that Tatis may have been a bit unlucky in 2020. He posted a .306 BABIP which is only slightly higher than the league average. A player as gifted as Tatis who has elite power and 98th percentile sprint speed should be sporting a much higher BABIP. That demonstrates that some hard-hit balls were hit right at defenders and that he didn’t receive his fair share of bloop hits. Keep in mind that a 149 wRC+ is nothing to scoff at. However, his xBA of .296 and xSLG of .608 show that he was even better than his actual results.
Another area that Tatis improved significantly was his defense. In 2019 he put up a -8.8 UZR/150, -3DRS and -16 OAA. That -16 OAA ranked him in the bottom one percentile. This may be bewildering, because Tatis was regularly making highlight-reel catches in his rookie year, but he also made some rookie mistakes. In 2020, his numbers improved dramatically across the board. In 57 games at shortstop, he posted 2.6 UZR/150, 1 DRS, and a whopping 9 Outs Above Average (OAA) which was the best mark amongst all major league shortstops. He went from being the worst defensive shortstop (according to Statcast) to being the best.
The best part about this defensive explosion was that it was well-rounded. In 2019, he really struggled coming in on the ball to a tune of -13 OAA, but also struggled on balls that brought him towards first base side (-4 OAA). He did better, but not great, on balls hit towards third base and on balls that he had to move back for (0 OAA and 1 OAA, respectively). In 2020, all of those marks improved. He gained 2 OAA on balls he had to come in on, 3 OAA on balls that brought him towards first, 1 OAA on balls bringing him towards third and 4 OAA on balls he had to go back for. That is a huge improvement for any player to make, let alone a 21-year-old shortstop.
So where does he go from here? Besides making even more contact and cutting the strikeout rate down a bit more, the biggest area Tatis could improve on is by elevating his batted balls more often. A 7.6 degree career launch angle is not terrible, but it is still lower than the league average 11.9 degree launch angle. His career 1.36 GB/FB rate would ideally get closer to that 1.0, which in turn would bump up that launch angle and lead to more extra-base hits. With his elite power, he should be looking to hit as many balls in the air as possible. If he can do this while keeping the other gains he made in 2020, the sky is the limit for this young phenom in 2021 and beyond.
