2020 Review — HR/FB Rate Positive Validations

Now that we’re through understanding the xHR/FB v4.0 equations and its components, let’s finally use it to evaluate past performance and help forecast 2021 performance. Today, I’ll share a list of names who enjoyed a breakout HR/FB rate in 2020 and their xHR/FB rate validated that surge (including surprising marks from players who didn’t play in 2019). Over small samples, luck plays a greater role, so knowing which spikes were real, based on the underlying skills displayed, is more important than ever when looking toward 2021.

What follows is a list of fantasy relevant hitters who either enjoyed a HR/FB rate surge from 2019 or posted a surprise mark in 2020 after not playing in 2019. I limited the population to only those who recorded at least 30 fly balls and line drives so at least we have some sort of sample size that’s not ridiculously small. It’s subjective what I consider to be “validated” by xHR/FB rate, as I didn’t employ a hard rule on the maximum difference between HR/FB and xHR/FB to be included on the list.

You gotta love when a hitter misses an entire season due to injury and then returns the following year to post the highest HR/FB rate, ISO, and wOBA of his career. That’s exactly what Salvador Perez did. Of course, it came over just 156 plate appearances, so he could have had multiple streaks throughout his career of such hot hitting. But clearly this is a pretty good indicator that he was healthy! And that’s the most important thing.

According to the Roster Resource Mariners team page, Jose Marmolejos is currently in line to act as the starting left fielder, on the strong side of a platoon. I’m not sure that playing time outlook is going to last by the end of Spring training, but his power means that you at least need to remember he exists. Already 28, he’s no longer a prospect, but enjoyed a power breakout in the minors in 2019, which carried over in a short sample to the Majors in 2020. He didn’t strike out too often in the minors and posted solid BABIP marks, so it seems if given an extended look, he could hit enough to keep a job. The Mariners have a number of outfield options though and some top prospects waiting in the wings.

It was probably not a surprise to most, but this is just confirmation that Luis Robert’s xHR/FB rate almost perfectly matched his actual mark.

Evan White skipped Triple-A and wasn’t known to have big power, so it surprised me that he managed to post a near 20% HR/FB rate. His xHR/FB rate suggests that if anything, he actually deserved even better! Obviously, that insane strikeout rate has to come down, but it’s just a matter of swinging more at pitches inside the strike zone, as he didn’t whiff at an exorbitantly higher rate than the league.

Wow, I don’t think anyone saw this kind of power coming from Willi Castro! He did post a 14.3% HR/FB rate back at Double-A in 2018, but that came over just 105 at-bats. Outside of that stint, he never posted a double digit HR/FB rate until 2020, and it was even supported by his xHR/FB. Combine the surprise HR/FB rate (even if it’s validated by xHR/FB) with the super inflated BABIP, and you have a recipe for a major step back in 2021. That’s fairly obvious though as no one expects Castro to wOBA close to .393 again. He could still earn some fantasy value though with a touch of power and speed, which he hasn’t shown in the Majors yet, but has shown in the minors.

Jesse Winker failed to qualify for the HR/FB leaderboard, but he would have finished second if he recorded enough at-bats. While he still outperformed his xHR/FB rate by over 8%, an xHR/FB rate over 30% when he had never posted a HR/FB rate over 24% is pretty darn impressive. So yeah, over the small sample of at-bats, this power outburst was mostly for real. Can he do it again? I doubt it, but he was a legit monster in 2020.

I included Leody Taveras here because although he outperformed his xHR/FB rate, he skipped Triple-A and had never posted an actual HR/FB rate over 5.8% in the minors. Pushing both his xHR/FB rate and actual HR/FB into the teens was a surprise, at least to me. There’s some real fantasy intrigue here, but the risk stems from the high strikeout rate and his performance regressing without that Triple-A experience.

After two straight seasons with a HR/FB rate between 11% and 12%, Colin Moran’s high 20% HR/FB rate was one of the bigger surprises of the short 2020 season. Amazingly, his xHR/FB rate was even higher. Unfortunately, his strikeout rate ticked up again and he simply isn’t hitting the ball in the air enough to take full advantage of these newfound home run hitting skills.

Gosh Juan Soto is good.

It’s amusing to me to see Jose Abreu’s draft cost rise because of a career half season at age 33. Sure, he was more awesome than usual, but he’s 34 now and it would be a surprise if he established a new level of skill, rather than just enjoyed a hot two months.

It took a while, but Travis d’Arnaud is fiiiiiiiiinally making good on his former prospect promise. A rebound in fly ball rate could offset a decline in HR/FB, but his BABIP is going to crash down and I wouldn’t just forget about his checkered health past.

Brandon Belt has massively underperformed his xHR/FB rate every single season, thanks to a home park that is consistently the most unfriendly in baseball for left-handed home runs. But in 2020, he upped his xHR/FB rate enough to push his actual HR/FB rate to a career best. Man would I have loved to see him in a different uniform in a more home run friendly park.