Is Pete Alonso the Greatest Home Run Hitter of All Time?

Pete Alonso is a specialist. He’s not one of those boring types, though: defensive replacement, pinch-runner, long reliever, LOOGY, the list goes on and on. He’s the kind of specialist that every team would take more of: a home run specialist. You might not notice it, because every star hitter is seemingly also a slugger these days, but Alonso isn’t like the rest of them. He’s out there for the home runs, and everything else about his game simply works in support of that.

That’s a vague statement, but I really think it’s true. To me, there’s no player in baseball today who is a more pure home run hitter. Given that we play in one of the homer-happiest eras in baseball history, and that players today train harder than at any point in the past, he might be the best home run hitter of all time.

Let’s start with a simple fact: since Alonso debuted in 2019, no one has hit more home runs. He’s 13 homers clear of Aaron Judge in second place, with a whopping 156. This isn’t a case of a pile of extra-base hits with some going over the wall, either. Of the top 15 homer hitters in that span, only Judge has a higher proportion of home runs as a share of all extra-base hits. Alonso isn’t up there spraying balls into the gap; he’s up there trying to give fans souvenirs:

Want a catch-all description for the kinds of batted balls that turn into home runs? You need to hit the ball in the air, but not too high, and you need to hit it hard. More specifically, 98.2% of home runs hit since the start of 2022 have had a launch angle between 15 and 40 degrees, and 98.5% of home runs came off the bat at 95 mph or harder. In the air, hard: it’s a simple recipe.

Across all of baseball, hitters try to do just that. Since Alonso debuted, 15.4% of all batted balls have satisfied those criteria. Alonso checks in right around 20%, in the top quintile of all major league hitters in this particular metric. He’s also great at even more likely home runs; narrow those bands to 100 mph or harder and 20–35 degrees, and he stands out just as much. Six percent of all batted balls fit those buckets; Alonso is in the 88th percentile across all batters with a 10% rate.

You’ll notice that those numbers aren’t the 99th percentile. Alonso is really good at lifting the ball, but not the best. He’s really good at hitting the ball hard, but not the best. He has something else working in his favor, though. Many home run hitters fill up on empty calories — walks and strikeouts that could never turn into home runs because they’re not even a ball in play. Strikeouts are clearly bad, and if your objective is to hit a home run, walks aren’t much better (they’re slightly better because they make it more likely that you’ll get to bat again). Alonso doesn’t have that problem.

Let’s take a look at that list of the top home run hitters again. This time, I’m going to add another column: percentage of plate appearances that end without contact. That means walks, strikeouts, and HBPs. You can see two categories of hitter in this list: powerful guys like Judge and Schwarber who walk and strike out fairly often in pursuit of launching bombs; and bat control types who hit their home runs because they put a ton of balls in play overall, like Semien, Devers, Arenado, and Ramírez:

Alonso sticks out. No one else who crests the 50% mark in terms of homers-per-extra-base-hit puts the ball in play more frequently than he does. And he’s not exactly sneaking over that 50% line, either: he’s second only to Judge in home run share, as we already discussed up above.

That combination of frequent balls in play and also frequent home runs is unique. Every other hitter who maximizes their extra-base hits like Alonso does racks up a ton of strikeouts and walks in the bargain. Everyone who has a similarly ball-in-play-oriented game does so by sacrificing at least some contact quality. I’m not saying that Arenado doesn’t hit the ball hard, but he’s not hitting it Alonso hard. You just can’t live in that happy realm of huge damage on contact and frequent contact — unless, of course, you’re Pete Alonso.

We’ve already squarely left the realm of trying to figure out who the best hitter is. Counting walks and strikeouts as equivalent handled that, to say the least. Since I’m hunting for the best overall home run hitter, though, I’m about to introduce some further evidence in Alonso’s favor that’s hardly based on WAR or anything approaching it.

One underrated factor in launching a ton of home runs is availability. You can’t hit a home run if you’re taking a day off to rest or on the shelf with a hamstring strain, or any number of other reasons that a player might miss time. I’m completely willing to believe that managing playing time lower is a great way to prevent injury, but to be the greatest home run hitter of all time, you can’t be taking days off. That means playing first base, the least taxing position on the field, and avoiding injury.

Alonso succeeds on both counts. He’s fifth in the majors in plate appearances since the beginning of the 2019 season, behind Semien (truly remarkable for a middle infielder) and three first basemen. To the extent that showing up every day makes Alonso a great home run hitter, he has that completely covered. Maybe Mike Trout would be the best home run hitter of our generation if he didn’t miss a lot of time with injury, but, well…

When you put it all together, Alonso’s record is hard to top. He lifts and elevates. He doesn’t run a gaudy walk rate or a hideous strikeout rate, which means more balls in play. He shows up every day, which means more chances to put a ball in play. Add it all up, and I feel confident in saying at least this much: Alonso is the best home run hitter of our generation.

The natural next question: how does he stack up with great home run hitters historically? Is his most recent four-year run one for the history books? In a word, no. This is hard to comprehend, but Mark McGwire hit 245 homers from 1996 to ’99, and Sammy Sosa hit 243 homers from ’98 to 2001. That’s 60 a year. No amount of massaging is going to get Alonso to that level.

That said, some amount of massaging is required. The pesky shortened 2020 season makes it hard to compare Alonso’s output to his historical counterparts. I tried two different methods to account for it. First, I took his average plate appearances per year in every other season and pro-rated his home runs up to that number. That added 29 homers, for a total of 173 in four years. That’s a top-40 performance of all time. Second, I ignored 2020 and compared his run in ’19, ’21, and ’22 to the best three-season totals. That’s a top-70 performance of all time, though well behind McGwire’s ridiculous 193 from 1997 to ’99. In either case, Alonso is a great home run hitter, but he’s not on the best four-year run of all time.

Given that, I guess I’d say that Alonso isn’t one of the top few home run hitters of all time yet, at least in terms of how many he’s hit to start his career. The fact that he’s even in that discussion at all is impressive for someone who didn’t debut until 24, though, and he has plenty of time to add to his record. He might never reach the wild levels of the late 90s home run chase heroes, but no one in baseball today looks like a better bet to churn out 45-homer seasons year after year for the foreseeable future.

If you want to make an argument that Alonso is the best pure home run hitter of all time, there’s still a case. It boils down to this: baseball players are the best they’ve ever been. Every pitcher throws 95 mph with a wipeout slider, every hitter lifts weights and watches video nonstop. Baseball is professionalized to a level that dwarfs past eras, and in that era of widespread improvement and training, Alonso is the best there is when it comes to hitting home runs.

Really, it’s all academic. Where Alonso ranks on some list of old retired home run hitters doesn’t have a lot to do with what he’s going to do tomorrow. But he’ll probably hit a home run tomorrow, or the next day if not. He’s built for it. He’s built for it more than anyone else playing right now. At the end of the day, that’s the one thing I can say for certain.