When it comes to drivers, Mizuno isn’t usually the company that comes to the top of mind for many golfers, but starting with the ST-190, and then the ST-200 series in 2020, they have quickly changed the perception of their metal woods thanks to wins on tour and more players choosing to put them in play—most recently Brandt Snedeker as a non-contracted player.

This morning, with the update of the USGA and R&A conforming equipment lists, we are getting a sneak peek at what Mizuno will have in store for 2021 with the release of the ST-Z and ST-X drivers.

What we know

Based on the information provided in the USGA submission by Mizuno, the ST-X will only be available in right-handed (10.5 and 12-degree lofts), while the ST-Z will be available in both right (9.5  and 10.5 degrees) and left-handed (9.5 degrees only).

ST-Z

Based on the images from the USGA list and our experience with the Mizuno product line, it appears that the ST-Z is the next step in the evolution of the standard ST200 with no adjustable CG but with a customizable weight in the back of the head.

We haven’t seen any images of a moveable weight driver in this new ST series, so it could be that the G-woods are getting phased out in favor of more internally biased weighting, but since those types of drivers often take a bit more time to get just right, it could be a matter of time before a “G” type driver hits the list.

As for technology, it has Mizuno’s standard wave to create flexibility behind the face, an adjustable hosel, and based on the images, more carbon fiber used around the head compared to previous generations, especially on the sole. I would also expect to hear a new face material or design story to complete the package and to boost MOI and ball speed.

ST-X

Based on the image from the USGA list and our experience, it appears that the ST-X is the next step in the evolution of the ST200-X driver, which is the lighter weight, more upright, and draw-biased driver from Mizuno. Don’t think draw bias always means it’s for higher handicaps either, because Mizuno staff player Chris Kirk got along very nicely with his out on the Korn Ferry and PGA Tours in 2020, including a win.

The tell-tale sign is the more heel biased weight in the back of the driver and what looks to be some sort of textured area to create “visible technology” towards the heel of the clubhead.

Beyond being draw-biased, when it comes to technology, it shares a lot of similarities to the ST-Z with Mizuno’s standing wave to create flexibility behind the face, an adjustable hosel, and more carbon fiber used around the head compared to previous generations, especially on the sole, and in the case of the ST-X, on the sole.

We don’t have any information on the release of these new drivers, but considering Mizuno didn’t adjust product release schedules in 2020, I would imagine it will be doing the same in 2021, and we can expect to hear more about these ST drivers either late 2020 or early into 2021.

To see what other golfers are saying about the newly spotted Mizuno ST-Z and ST-X drivers, check out the GolfWRX forums and join the discussion: GolfWRX – New Mizuno drivers spotted on USGA Conforming List