I am making a vim golf app, https://vimgolf.ai , for my side project where users compete with an AI vim opponent to learn vim and so far claude 4 sonnet (haven't tried opus) is ranked the highest in my evals against o3, o4-mini-high, and gemini 2.5 pro. After 3 retries, it solves this challenge:

https://www.vimgolf.com/challenges/5957c3356f7e17045b00002c

here is a snippet of its thinking process pinpointing the exact problem with getting it to successfully transform the start file to the end file:

So I need to add a space between "string" and the backtick.

Let me think about what's happening. In my commands:

1. `5G$a `xml:"field1"``<Esc>` 2. `6G$a `xml:"field2"``<Esc>` 3. `7G$a `xml:"field3"``<Esc>`

The issue might be that I'm not actually including a space character in my command. Let me be very explicit about this. I need to use `<Space>` to represent the space character.

some feedback for your app. I'm just dumped on a screen and left to my own devices, zero hints, prompting etc.

At no point am I "learning vim through challenges"