Adidas Adizero Adios Pro 4 vs Adidas Adizero Adios 9:
Which to Choose

The clearest split is stack and cushioning. The Adios Pro 4 rides on a tall, max-ish platform — roughly 37mm at the heel and 29mm at the forefoot in the lab (Adidas lists 39/33) — with dual-layer Lightstrike Pro, where the Adios 9 is deliberately low at about 25mm/19mm with a single full-length layer of the same foam. That's the difference between a plush, protective ride that saves your legs late in a marathon and a firm, ground-connected feel that rewards you only once you're flying. Drop is near-identical at around 6mm on both, so foot position and turnover feel similar, but the Pro 4 is the heavier of the two at about 200g versus 176g for the Adios 9 (men's) — the Adios 9 is the lighter, lower, racier-feeling shoe on the foot despite the Pro 4 being the more advanced piece of technology. Propulsion also differs in kind: the Pro 4 uses carbon-infused EnergyRods for an aggressive, tipping-forward rocker that snaps hardest at true elite pace (roughly 3:00–3:20 min/km), while the Adios 9 swaps carbon for a nylon shank, keeping the ride more flexible and direct and happiest in the 3:30–4:00 min/km zone over shorter distances. Neither is stable or supportive — both are neutral — but the Pro 4's tall, narrow platform is genuinely tippy at easy speeds, whereas the Adios 9's low deck is more planted simply because there's so little stack to roll on. In short: Pro 4 is a long-distance super-shoe, Adios 9 is a short-distance speed flat, and they only overlap at the 10K.