Vladimir Guerrero Jr. and the Greatest Postseasons of All Time

At the conclusion of the ALDS, I wrote an article about Aaron Judge’s postseason. Across seven games and 31 plate appearances, the Brobdingnagian slugger ran a 253 wRC+ with a slash line of .500/.581/.692. If you set a minimum of 30 plate appearances, then that 253 wRC+ ranks 14th among all postseason performances. That last sentence contains a good bit of statistical misdirection; that 30-PA cutoff eliminates most of the players in postseason history, but it’s still low enough to let an outlier like Judge shine. Still, my goal was to highlight how brilliant Judge had been while also trying to create a framework for putting postseason numbers in context. The tiny sample sizes make that really hard to do, and that was part of the point. But Judge wasn’t the only player who excelled this postseason. In that same Divisional Series, Vladimir Guerrero Jr. got 20 plate appearances and batted .529 with a 324 wRC+. Ernie Clement put up the exact same 324 mark with a .643 batting average over 16 plate appearances. I didn’t mention them in the article because of those smaller sample sizes, but I planned to keep my eye on them. They didn’t disappoint.

Guerrero batted .385 with three home runs in the ALCS, running a 250 wRC+. As you may have heard, he had a pretty good World Series, too. He batted .333 with two homers and a 192 wRC+. Put it all together, and Guerrero slashed .397/.494/.795 with eight homers, 18 runs scored, and 15 RBI in the playoffs. He got intentionally walked six times. Should we watch all eight of those homers? Of course we should. There is no excuse too slight to watch all eight of those homers.

Over the entire postseason, Guerrero posted a wRC+ of 241, leaving him just 14 points behind Judge. Going back to our minimum of 30 plate appearances, that’s the 25th-highest mark of all time. But Guerrero didn’t just leave Judge’s 31 plate appearances in the dust, he set an all-time record with 89. His sample was nearly three times bigger, and he was still just 14 points behind!

As we established, over those extra 69 plate appearances in the ALCS and World Series, Guerrero continued his excellent play, so it’s time for an update. Let me show you the graph I made a few weeks ago to show you how much of an outlier Judge was. The red circle is Judge. The green dot is Barry Bonds’ absurd 259 wRC+ performance from the Giants’ 2002 World Series run. I’ve added an orange dot to highlight where Guerrero was at that point.

“This certainly makes Judge look a bit less spectacular,” I wrote at the time. “He’s up toward the top of the heap for a player around 30 plate appearances, but he’s not standing out from the pack the way Bonds did. According to this chart, the most impressive performance in postseason history is undoubtedly Randy Arozarena’s magical, homer-filled 2020 run with the Rays, all the way to the right.” At that point, Guerrero was higher than Judge in raw wRC+, but he was at roughly the same place on the trendline. He was right near the top, but at the 20-PA mark rather than the 30-PA mark, which made it a bit less impressive. Well three sublime weeks later, we can now update this graph. Judge, Bonds, and Arozarena are no longer highlighted. The only dot I’ve highlighted is Guerrero’s and it’s not hard to see why. He stands alone. There’s a brand new dot in town.

What we’re essentially illustrating with this graph is weighted runs created – removing the plus from weighted runs created plus. The higher and further to the right you are, the more runs you’ve created. We’re turning this back into a counting stat in order to look at the players who have put up the most offensive value in a single postseason, and Guerrero just set the record. Here’s the top 10:

If you want to argue about the best single-season playoff hitting performance of all time, you have plenty of metrics to choose from. Without a PA minimum, the highest postseason wRC+ of all time belongs to Jim Mason, who homered in his one postseason plate appearance with the Yankees in the 1976 World Series. Because the league had a paltry .681 OPS that year, his home run was weighted more heavily than the three other players who homered in their only postseason plate appearance. He has a career postseason wRC+ of 1,432, quite a bit better than his regular season mark of 53.

If you set a minimum of 15 plate appearances in order to include players from the time when the World Series constituted the entirety of the postseason, then you’ve got Lou Gehrig’s 419 wRC+ when the Yankees swept the Cardinals in 1928. Gehrig went 6-for-11 with a double, four home runs, six walks! He made just five outs in four games and ran a slash line of .545/.706/1.727.

If you’re interested in win probability added, then the Cardinals get their revenge in the form of David Freese’s absurd 2011 run. His 1.91 WPA puts him on top. He was impossible to retire, and because he was batting behind the triumvirate of Albert Pujols, Matt Holliday, and Lance Berkman, who combined for an on-base percentage of .444, he was always coming to the plate with runners on base in high-leverage situations.

But if you’re just talking about sustained excellence, then the answer is clear. The crown once belonged to Bonds, then Arozarena. It now belongs to Guerrero.