Stealth Rock still decides more games than any other move

Every ladder game opens the same way. Somebody clicks Stealth Rock on turn one, the other player either removes it or decides the removal slot is not worth a teamslot, and the rest of the match is quietly played inside that decision. The move does no damage on the turn it is used and it is still the single most consequential button in the tier.

The reason is not the chip itself. It is that the chip is not evenly distributed. A neutral target loses 12.5% and shrugs. A 4x weak target loses half its health before it has done anything, and that is not a cost — that is a ban list written in damage percentages.

What the numbers actually say

Rock deals damage as if it were a Rock-type move hitting for one eighth of max HP at neutral effectiveness, scaled by type matchup:

The bottom two rows are the whole story. A Pokemon that loses a quarter of its HP per entry cannot pivot, and a Pokemon that cannot pivot cannot do its job on a team that is trying to win a long game.

Who sets it, and why the setter matters

Setting hazards is easy. Setting them and keeping momentum is not. The reliable setters in the current OU metagame fall into three groups:

• Pivot setters — Landorus-Therian and Great Tusk set Rocks on a forced switch and leave with U-turn or Rapid Spin. They cost nothing in tempo, which is why they are on roughly half of all teams.
• Wall setters — Ting-Lu and Clodsire do not care about being switched into. They set, take a hit, and set again after removal. Slow, but almost unpreventable.
• Trade setters — Glimmora leads, sets, and expects to die. In return you get hazards up before your opponent has developed a board at all.

The distinction matters when you build. A trade setter puts hazards up once. A wall setter puts them up four times. If the opponent has Great Tusk plus Rapid Spin, the trade setter has effectively done nothing by turn twelve.

Removal is not optional, it is a slot

There are three ways out and each one has a real cost:

1. Rapid Spin — clears your side only, fails against Ghost-types. Gholdengo exists specifically to punish this line.
2. Defog — clears both sides, which is a downside if you are the one with Spikes stacked.
3. Do neither, and run Boots on everything that cannot afford the chip. Cheapest in teamslots, most expensive in item slots.

Hazard control is not a slot you add to a team. It is a decision you make about how the team wins, and every other slot is downstream of it.

The practical build rule

Count the members of your team that lose 25% or more on entry. If the answer is two or more, you do not have a hazard problem — you have a team that only functions when hazards are already gone. That is a bet placed on your opponent misplaying, and it is the most common reason a strong-looking six loses to a worse one.