Google will offer you a one-click AI Max test. Write the win condition before you click.

Short answer: Google Ads now offers eligible accounts a "1-click experiment" recommendation that splits a Search campaign 50/50, AI Max off against AI Max on. The click is easy. Before you take it, write down the metric that decides the winner, how long it runs and what makes you stop it early. (Search Engine Roundtable, Oct 26, 2026; Google Ads Help, answers 15913066 and 16450159)

TLDR

• One click sets up a 50/50 split inside your existing campaign. (Google Ads Help)
• Google suggests 4 to 6 weeks when results aren't yet determined. (Google Ads Help, Experiments page)
• Metric, run length, kill rule. Write them first.

How does the 1-click AI Max experiment work?

Google's AI Max FAQ says: "If your account is eligible, you may find a 1-click experiment recommendation on your Recommendations page. When you select Create 1-click experiment automatically, it sets up a 50/50 split test comparing your base Search campaign against an AI Max treatment arm without requiring manual configuration." (Google Ads Help, answer 15913066, quoted by SER Oct 26, 2026)

The control arm keeps AI Max off. The trial arm turns it on. It splits traffic and budget inside the existing campaign instead of copying it. (About AI Max experiments, answer 16450159, read Oct 26, 2026)

Can I test only some ad groups?

Ad-group-level controls may not be available at initial experiment setup, per Google's help page. (About AI Max experiments, https://support.google.com/google-ads/answer/16450159, checked Oct 26, 2026)

Why write the win condition first?

Because once the test is live, every number looks like an argument. Pick the one that matters to the client's business before you see the data.

If an agent or automated rule will run the test, the same order holds: write the checking rules before you hand work to an agent.

What goes in the win condition?

1. The metric: cost per conversion, conversion value, or qualified leads. One.
2. The threshold: how much better the AI Max arm must be to win.
3. The run length: Google's Experiments page suggests at least 4 to 6 weeks if results are still undecided.
4. The kill rule: the spend or lead quality line that ends the test early.
5. The search term review: who reads the new queries AI Max matched, and how often.

What does skipping this cost?

A test that ends on a feeling. Then the client asks why spend moved, and the answer is "the recommendation said so."

Next step

Who: the paid search lead. What: a one-page win condition per campaign you plan to test. When: before you accept the recommendation. How: the five fields above, shared with the client before launch.