Luis Arraez Really Could Hit .400

As one would expect, records and milestones often reflect the eras in which they’re achieved. Pitching records tend to be set in low-offense eras, while offensive milestones rack up more quickly at times when runs are plentiful. As the game ebbs and flows, certain benchmarks that are achievable in one era become far more difficult, or even impossible, in another. One of these achievements, which has long fascinated fans, is hitting .400. Even as batting average became a less relevant number in the post-Deadball era (and even less so as front offices gravitated toward other metrics 75 years later), baseball observers have still rooted for someone to hit .400. I’m one of them; not everything that’s fun has to be an amazing analytical tool, and vice-versa. Hits are, for lack of a better word, cool, and the ability to rack up value primarily via batting average has become far rarer than it used to be. And if hits are cool, Luis Arraez is in super-rad territory, as the Marlins second baseman is currently sitting at .398 as we approach the season’s halfway mark.

Whether you think the most recent .400 hitter was Ted Williams, who put up a .406 average in 1941, or Josh Gibson, who put up an impressive .466 for the Homestead Grays in 69 games a couple of years later, there are very few baseball fans remaining who have a living memory of a .400 hitter. After the Splendid Splinter hit .388 in 1957, it was another 20 years until anyone came that close (Rod Carew in 1977). There were always scattered attempts, such as George Brett‘s effort to sneak up to .400 when he hit a stunning .421 in the second half of the 1980 season (he ran out of calendar, finishing at .390). The offensive outburst of the 1990s wasn’t just in home runs, but in batting average as well, and there was another mini-run of .400 attempts. From 1993 through 2000, there were a surprising number of first-half hitters above .380: Tony Gwynn (twice), Larry Walker, Nomar Garciaparra, John Olerud, Darin Erstad, Todd Helton, Frank Thomas, and Paul O’Neill. Nobody’s been at .380 in the first half more recently, and since 2010, only Justin Turner’s gone into the All-Star break with a batting average north of .370.

As I noted above, records tend to be set in eras that are friendly to those achievements. The league hit .270 in 2000. This year, that figure is .248; the league hasn’t hit .260 since 2009. The lack of .400 hitters isn’t just a change in approach, either. While players are less focused on batting average these days, from 1901 to today, no qualifying player in a season of at least 100 games has beaten .390 in a season in which the league hit .260 or under:

Simply put, no player who isn’t an inner circle Hall of Famer has hit even .370 in a low-batting average environment since the Deadball Era, so Arraez’s .398 in the first half has earned some raised eyebrows. Indeed, my colleague Michael Baumann examined Arraez’s strong start just a few weeks ago, back when he was only hitting .392. There are still a few weeks go to complete the first half of the season, but if Arraez can hold onto his current average, he would have the third-best first half batting average since Teddy:

We aren’t taking it easy on Arraez by only considering his performance through June 21, either; he’s only seven games short of Musial and is nearly a dozen past Carew.

So, will he do it? Probably not. But the scenario in which he does finish the season with a four as the first digit isn’t impossible or even implausible, just unlikely. Let’s run this through the ZiPS projections.

Like the in-season model, the full ZiPS model sees Arraez as a .334 hitter over the rest of the season. Since he’s projected to have less than half of his final 2023 at-bats (using ZiPS playing time), he would need to hit .403 over his 290 at-bats to finish the season at .400. I’m also not rounding up here; .3999999999 is not .400. Hitting .400 would mean 117 hits in those 290 at-bats, so to figure out his chances of getting those 117 hits, we could start with his .334 batting average and get a 0.79% chance of Arraez finishing at or above the .400 mark.

We could do it this way, but we’d be wrong.

ZiPS thinks Arraez is a .334 hitter but the system is aware that it’s not actually sure of that. He might be a .290 hitter or a .320 hitter or a .370 hitter. ZiPS doesn’t really know, and sees his underlying probability of a hit being a whole distribution around .334, not precisely .334. That uncertainty is what gives him a better chance than 0.79%, at least by the ZiPS’ estimation of his abilities. Because if Arraez is occasionally a .360 hitter, that’s a bigger boost to his chances than occasionally being a .300 hitter damages them.

Through Wednesday’s games, ZiPS thinks that Arraez will, on average, finish the season with a .364 batting average. That’s impressive in itself, the best batting average since Joe Mauer’s .365 in 2009 (I’m not counting DJ LeMahieu’s .364 mark in 50 games in 2020). But you’re really here for that sweet .400 fan service, and ZiPS thinks Arraez will deliver on that 2.9% of the time, or about once in 35 tries (sadly, he only gets one attempt this year). That’s unlikely but easily within the realm of possibility. Marcus Semien has hit a home run in 2.9% of his plate appearances this year; it’s not a likely result any given time at the plate, but I guarantee your mind isn’t completely blown when he knocks one over the fences. Arraez also has a 1.1% projected chance of catching Williams at .406. Nap Lajoie’s .426 from 1901 is sadly in that realm of implausibility, but I’m not greedy enough to be disappointed about that one.

Arraez isn’t likely to finish at .400, but he has a real chance. Hitting .400 is rarely easy, and these days, it would be a monumental achievement. If it were easy, then it wouldn’t matter. Plus, Arreaz has already achieved one feat that few would have ever expected: he’s made watching the Marlins bat must-see TV!