Evaluating Increases in Home Run Rates

Much smarter folk than I have already covered just how much hitters are suffering in this new and not-improved 2022 run environment, so let’s focus on some positivity and take a look at which players have thus far seen significant power bumps in the early goings on.

Out of the hitters with at least 100 PA both in 2021 and 2022 (n=199) heading into yesterday’s action, 29 players have seen their home run rate increase by at least 0.01 HR per PA (or an extra HR per 100 PA). And just as we all predicted, Christian Walker leads the pack.

Increases in home run rates are great and all but are only a unit for describing the past. To get to the bottom of sustainability, we’re much better off looking at things like Barrel% (barrels per batted-ball event), Air% EV (average EV for FB+LD), and Air% 100+ mph (balls hit in the air at 100 mph or greater). So that’s what we’ll do!

But while the metrics above are some of the best for predicting future (and describing past) power, we’ll also be referring to some of the other Statcast-based metrics from EV Analytics that you may not be as familiar with but are also useful for getting to the bottom of a player’s power profile. From the EVA glossary:

Exit Velocity (Top 5%) – The average exit velocity of the top 5% of the hardest balls the player hit.
Exit Velocity (Next 20%) – The average exit velocity of the top 5% through 25% of the hardest balls the player hit (note this does not include balls in the top 5%).

And finally, since MLB switches out baseballs like “insert hilarious joke of your own choosing”, let’s also look at the percentile ranks for each metric to better know their value relative to their peers. Mix those percentiles with our aforementioned metrics, add some conditional formatting, and Voilà!

A chart:

After hitting 29 HR in 2019, it seemed that Christian Walker was hitting his power prime but has become a fantasy also-ran after hitting just 17 HR combined in 2020-21.  However, there were some signs of life in the second half of last season, with Walker rising to an 8.2% Brl% after a 4.7% Brl% in the first half and a 6.4% Brl% in 2020.

But that small sign has turned into a full-fledged heartbeat in 2022, with Walker running a 16.7% Brl% that is currently in the 95th percentile. So, is this a dead-cat bounce out in the desert or has the 31-year-old Walker rediscovered his power stroke?

Given the across-the-board improvements in our key power metrics, I’m more inclined to believe the latter. Walker has not only seen some of baseball’s biggest improvements in Brl%, Air% EV, and Air% (100+ mph) but his already excellent plate discipline (20.1% K%, 10.2% SwStr%, 10.5% BB%) has gotten even better as he’s decreased his monkeying around the zone.

Walker’s 45% Swing% in the Shadow zone is eight points below league average, dropping from 59% in 2021 and 57% in 2020, and his 13% Swing% in the Chase zone is down from 22% the past two seasons.

The 9 HR pops off of the page but Walker still seems average when looking at his total fantasy value, currently coming in as the #16 1B on the Razzball player rater. And the fantasy community has largely been treating him as such – Walker is just 18% rostered on Yahoo!, 9% on ESPN, and 38% on CBS. In the opinion of this humble NotBurt, this is a mistake.

Walker’s overall fantasy value might be low now but his 18 R and 18 RBI are both above average, with a .206 AVG being the anchor holding him down. But I’d bet on that rising, given his history, even with 2022’s spongeball. Walker has a .246 AVG for his career and is running a .281 xBA this season but is just getting killed by a .200 BABIP (career .296 BABIP).

As the average comes up, Walker’s value will rise and what’ll be left is a boring (but very useful) producer in four categories. But don’t just take my word for it; Walker’s low ownership from above is a far cry from how he’s being handled in the NFBC Main Event – he’s currently 97% rostered and 90% started. Sometimes it pays to listen to the big cats.

The home run rate of Brandon Marsh has significantly risen but this is not the power breakout that you are looking for. His 6.8% Brl% is down from 10.9%, his average EV on balls in the air has dropped 4 mph, and his Air% (100+ mph) is in the 56th percentile, down from the 80th. There are also drops in his Top-5% and Next-20% EVs, while his Air% has dropped five points from last season and his Pull% is down 11 points.

The above makes his new home run rate seem unlikely to continue, while a .232 wOBA, 50 wRC+, and 40.5% K% vs LHP don’t bode well for everyday playing time. And yet, compare Marsh’s ownership (Yahoo: 57%, ESPN: 28%, CBS: 60%), with that of Christian Walker. I’ll wait while you go swap them out.

Okay, I’m not waiting around any longer because it’s time to preemptively declare an official Andrés Giménez SZN! That’s right, a melon-farming SZN, son.

Giménez is currently the #60 hitter on the Razzball player rater but is rostered just 60% on Yahoo!, 30% on ESPN, and 65% on CBS. That’s right around the likes of Gavin Lux, Brendan Rodgers, and Eduardo Escobar, all of whom are having significantly worse fantasy seasons.

It’s not that Giménez has become a bomber but his 4 HR in 100 PA has already nearly matched the 5 HR he hit in twice as many PAs last season. And because of his speed and overall profile, that power doesn’t have exactly have to be Judge-ian in order for his fantasy value to blow up.

Giménez’s Brl% has risen to the 42nd percentile from just the 15th percentile in 2021, his Air% (100+ mph) is up from the 30th percentile to the 74th, and his average EV on balls in the air is up 6.5 mph, taking him from the 11th percentile to the 77th. His groundballs are down, line drives are up, and Giménez has been punishing all pitch types. He’s posted a .489 SLG and .538 xSLG vs fastballs (.380 SLG/.350 xSLG in 2021), .565 SLG and .422 xSLG vs offspeed pitches (.212 SLG/.243 xSLG in 2021), and a .563 SLG and .476 xSLG vs breaking pitches (.383 SLG/.305 xSLG in 2021).

Speed, average, and excellent defense have been his carrying tools but this power surge hasn’t exactly come out of nowhere, even if it hadn’t yet shown up in the majors, as Giménez also hit 1o HR in 233 PA at Triple-A last season. But again, because of the five-category profile, Giménez doesn’t need to hit 30 HR to be a fantasy star.

Giménez is running around a 25 HR/20 SB pace over 600 PA but even a 20/20 season would put his potential in a small group of players, with only 10 players in 2021 accomplishing the feat. But add in a .275 AVG minimum and we’re left with just four – Trea Turner, Bo Bichette, Cedric Mullins, and Fernando Tatis Jr. Giménez obviously doesn’t have their ceilings, as 20-25 HR seems to be his most likely cap, but it does go to show just how rare the profile is.

He’s still batting down in the 6th/7th spot but given the performance of his teammates recently, Giménez could be in a position to move on up sooner rather than later. Over the past month, Amed Rosario is slashing .221/.287/.279, Steven Kwan is at .224/.302/.316, and the Owen Miller experience is severely slowing down, slashing .216/.277/.365, with a .284 wOBA. The best version of Giménez is a much better fit near the top of the order and if he ascends to it, he’ll reap all the PAs that come with it, not to mention the general benefits of batting in front of José Ramírez.

An-drés SZ-N, dun, dun, dun-dun-dun. An-drés SZ-N, dun, dun, dun-dun-dun.

Corey Seager has increased his home run rate, even after moving to a home park that is a shadow of its former launching pad self (and with baseballs featuring an all-new loofah core) but call me a little skeptical. Seager’s Air% average EV is still residing in the top-10% but a Brl% in the 68th percentile has dropped from the 85th in 2021, with his Air% (100+ mph) also dropping from the 87th percentile to the 66th.

Seager is pulling the ball more than ever (43.8% Pull% up from 33.8% in 2021) and a career-high 18.2 degree LA is helping to drive his (likely unsustainable) 60.9% Air%. But while his average launch angle is up, his LA% (+38 degrees) has risen from the 24th percentile to a career-high 76th percentile. These uppercut swings can increase home runs but will crater BABIP and a big part of Seager’s fantasy appeal is a batting average that’s been over .300 in four of his eight seasons (with a .295 AVG in another).

Do you think Seager should carry along his current swinging path? Because I don’t:

Swinging for the sky might be leading to a few more home runs but the cost seems far too high for fantasy purposes, given where his value has come from previously. And looking at the Razzball player rater, his fantasy values seem to agree. Seager is currently the #61 hitter – or one spot after Andrés Giménez.