About 27% of these customers left. Predicting "nobody leaves" is 73% accurate and catches no one, so the score that matters is F1, which balances precision and recall on the churners.
The line did most of the workAt a 50% line the model caught about half the leavers (F1 ). Moving it to did most of the improving. Three extra inputs helped a little.
Trees didn't winML.NET's gradient-boosted trees with their own tuned line reached F1 , just under this model, and their reasons can't be read off a coefficient.
Checked against ML.NETThe logistic regression here is fitted from scratch by Newton's method. ML.NET's own solver agrees on every test probability to within 0.00002.