Mizuno · Driver · 2021
ST-Z
CaddyIndex™ breakdown — what the agentic research found across each of the six performance dimensions, with cited sources.
Mid-to-low handicap golfers (HCP 0–15) with 90–120mph swing speed who want straight-line distance with low-spin tour-leaning character and best-in-class feel.
You fight a slice and need draw bias (use the ST-X stablemate), want maximum forgiveness in an oversized GI footprint, or need movable-weight adjustability for shape-tuning.
Pros
- Golf Digest 2021 Hot List Gold (3rd consecutive driver gold for the brand; part of an 8-gold sweep)
- Editorial coverage in 2021: 3rd best at protecting carry distance, 2nd best at protecting ball speed, and flat out 1st at controlling spin difference — top-quartile robot scoring
- TXG Official 2021 driver test WINNER — eliminated big-name drivers in head-to-head testing
- Topped PGA Tour driving distance (~326yd avg) at the 2021 Sony Open — the first time the ST-Z was put into play on tour by a brand staffer
Cons
- Only two loft options (9.5°, 10.5°) — no 12° head; less spread for slower swing speeds
- Single fixed back weight — no movable weight system for shape or spin tuning beyond the hosel
- Engineered for straight ball flight — limited workability for tour-aspirational shape-makers
- 4-year recency penalty — superseded by the ST-Z 220 (2022), ST-Z 230 (2023), then the ST-Max / ST-G / JPX One families
By dimension
Forgiveness
Independent reviewer testing called the head "THE most consistent driver tested in 2021" — spin rates remained at 2,020rpm across the test. Robot testing ranked the chassis 3rd best at protecting carry distance, 2nd best at protecting ball speed, and 1st at controlling spin difference — top-quartile 2021 forgiveness. Industry-awards Gold Medal cited lower spin and maximum forgiveness on off-centre hits. Balanced toe/heel carbon-composite construction with deep central back weight delivers high MOI without sacrificing low spin.
Distance
A tour staffer topped the PGA Tour driving distance stats at the launch tournament (326.1yd average) — the first player to put the head into play on tour. The chassis was ranked 2nd best at protecting ball speed across independent 2021 testing. 2nd-gen SAT2041 Beta Ti face (17% more tensile strength than 6-4 Ti) plus deep central back weight delivers low-spin / high-speed character. Top-tier 2021 distance.
Workability
Designed for straight ball flight — independent commentary positioned the head as suited for straight-line bombers rather than shape-makers. Tour-staff feedback noted the chassis "just wanted to go straight" with limited shape-imposition in player hands. Neutral central back weighting plus low/back CG pulls dispersion into the centre. Hosel offers 4° loft adjustability for tuning launch/lie.
Feel
Reviewer testing consistently called the feel "incredibly solid" — tour players specifically asked for a more solid or dense impact sensation, which the new Beta Ti face plus vibration-absorbing carbon fiber sole panels delivered. Reviewer testing noted: "this certainly isn't a 'soft' feeling club. It feels solid… when you catch it sweet in the middle, it is really satisfying." Best-in-class 2021 driver feel — forged-iron tactile DNA preserved.
Sound
Acoustic profile reads medium in pitch and fairly quiet — powerful but more muted than other drivers; more of a "ping" than a "crack." Misses are easily differentiated from pure strikes in both feel and sound, but mishits aren't harsh or unpleasant. Sound and feel were specifically targeted for improvement in this generation. Premium muted-quiet character.
Looks at address
Address profile reads as a very neutral look that strikes a fine balance between modern, cutting-edge aesthetics and classic shaping. Visible carbon-fiber sole panels with clean polished aesthetic. Industry-awards Gold panel rated the design favourably, and the chassis won an independent head-to-head 2021 driver test. Premium tour-leaning silhouette that ages well.
Sources
Some of the reviews, lab tests and head-to-head comparisons the agentic research read while grading this club.
- Mizuno ST-Z Driver Review - Plugged In Golf
- Mizuno ST-Z and ST-X driver Review - Today's Golfer
- 2021 Mizuno ST-X and ST-Z drivers - GolfWRX Launch Report
- Mizuno ST-X and ST-Z Drivers - MyGolfSpy
- Mizuno ST-Z Driver Review - A Driver You Should Consider In 2021? - Golf Monthly
- STRIKING GOLD: EIGHT GOLD AWARDS FOR MIZUNO IN 2021 GOLF DIGEST HOT LIST - The Golf Wire
- Mitchell tops distance charts with Mizuno ST-Z driver - Mizuno Golf
- Mizuno ST-Z crowned king of 2021 drivers by TXG Official - Mizuno Golf
- Mizuno ST-Z Driver Review: Exceptionally consistent - Golfmagic