Having children begin lessons before 4 does not mean they will eventually be better swimmers than those who take lessons later.

But unless he's a hell of a lot better swimmer than I think, he won't be trying anymore.

He was an expert sailor, an even better swimmer.

"But most of the better swimmers come from the Northeast."

She knew she was the better swimmer, but it no longer mattered.

She was a better swimmer than he; he stood idly watching her.

He spent far more time in the pool than Matyas and was the better swimmer.

I'll have you know I'm a better swimmer than you.

The boy was a better swimmer than his sister, but not so skilled as the elf prince.

The sentence is equivalent to "You are a better swimmer than she is."