I decided that I would do a "back of the envelope" evaluation of my tax liability for 2025. I gathered what I believe will be the various income amounts, capital gains and so on. My taxes are not overly complex except that the total includes US, NY State and NY City income tax amounts. Easy peasy.

So, I figured I'd ask five different AI's to run the numbers and see if they came up with the same results.

Two (Gemini and Copilot) gave me a "hand waving" answer with likely ranges of liability. So much for intelligence.

That left Grok, Claude (Anthropic) and ChatGPT which worked out, with extensive documentation all three tax rates.

Claud had some errors that I pointed out (in State rates) and did the whole run three times.

Between the three, there is about an 18% difference in Federal tax due, the State rate differs by more than a factor of 2X and the NYC tax is +/- 5%.

The errors offset each other on the totals which pulled a lot tighter than the individual line items.

The final total effective income tax rate:

GROK: 30.5%

Claude: 30.6%

ChatGPT: 33.9%

Let's see what the final numbers turn out to be in three months or so.

Jeff