The 2021 Mizuno Hot Metal BBCOR produced excellent exit speeds in our 32- and 33-inch testing. The feel was ordinary and end-cap misses were harsh, but the barrel performed. This review is for the BBCOR model.
Models Overview
Our hitters loved the exit speeds. The feel on the bat was good, but nothing to write home about. If you hit one off the end cap, you for sure felt it. But, that's the type of feedback some players prefer. In terms of straight exit speeds and overall performance in BBCOR, the B21 performed like highly recommended Rock Star.
Construction & Technology
The Mizuno B21 Hot Metal is a single-piece aluminum bat made from a single wall of aluminum. The bat wall adjusts it's thickness as it moves from the center of the bat to its outsides. This helps increase bat performance outside of the dead center of the bat. Several companies, including the CAT 8 from Marucci and Velo from Rawlings, use a similar tactic.
Performance Comparison
Compared to the 2020 Mizuno Hot Metal, there have not been a lot of changes. It is still a single piece aluminum bat with a big barrel and end load. Expect similar feel too. In either case, expect big hits if you can handle it.
Comparable Bats
There are plenty of single-piece aluminum bats with a big swing on the market today. Off the beaten path, you can find a bat like the Widowmaker from Anderson. In more traditional routes, look for something like the Omaha or 5150 from Rawlings. As well, our hitters like the Bonesaber from Warstic. Each of those bats listed does a great job on top-end exit speeds for those who can wield them well.
Also, the B21 is a lot like a CAT 8. Both have variable wall thickness and use a single piece of aluminum for the entire bat. Of course, the CAT 8 has some sting dampening technology in the handle, but in terms of barrel and performance, we think they are very similar.
Overall grade: A
Overall grade: A
Overall grade: A-
The Bottom Line
B20-HOT METAL BBCOR Baseball Bat combines Mizuno’s powerful HotMetal™ single-wall aluminum alloy with innovative CorTech™ technology, which adjusts wall thickness across the barrel to create a high-performance bat with an aggressive sweet spot. Engineered details like an Optimized End Cap create a booming sound, while also increasing the size of the sweet spot to give you the hottest one-piece bat in the game. (source)