I asked ChatGPT, Gemini and Perplexity for a lawyer in two US cities, 750 times. The names barely held still.

I work on an AI visibility tool, so keep that in mind. I'm not selling anything and there are no links.
What I saw (Phoenix / Chicago):

I wanted to see how stable "best lawyer in [city]" answers really are. I picked two searches, criminal defense in Phoenix and immigration in Chicago, and wrote 25 questions for each the way a client would type them ("best criminal defense lawyer in Phoenix", "I was arrested for DUI in Phoenix, who should I call?"). Then I asked every question 5 times on ChatGPT, Gemini and Perplexity. That's 750 answers.

What came out (Phoenix / Chicago):

- 151 / 159 different firms were named across all the answers.

- The top firm was in 54% / 53% of answers. The top three together were in 62% / 74%.

- Ask the same question twice on one tool and the two answers share only 46% / 42% of the names.

- About 4 in 10 firm mentions showed up in just one of the five runs.

- Only 21% / 24% of firms were named by more than one tool.

- In Phoenix, ChatGPT and Gemini gave no firm name at all in about a third of answers (34% each). Perplexity almost always named someone (6% none).

- Avvo, Super Lawyers, Expertise.com and Justia were each cited in roughly 36% to 48% of answers.

Caveats: I wrote the questions myself, not from search data. "ChatGPT" here is the API with web search, not the app. Location was set to the US only, the city is in the question. I used a model to pull out firm names, merged duplicates by a simple rule, and checked the top ten by hand. Two cities, two practice areas, and I didn't check whether the answers are correct. I'm leaving firm names out on purpose.

What I'm unsure about: how many repeat runs before you'd say a firm "gets recommended"? I used 5. And if you check this for local clients, do you count a name in a list as a mention, or only when it's recommended first?