My cat will play fetch for as long as I throw her little mouse toy. She'll even let me throw it from bed and she'll bring it right back up for me to throw again.
Only 2 of them did it their whole lives… Ginger now considers it servitude, but would literally fetch milk rings or mice until both my girlfriend and I got worn out… two and a half hours IIRC. She was so fast, like 30-40 mice a minute.