They would have experts on each animal assess their strengths and weaknesses, and come up with a likely scenario and predict the winner based all the variables.

The Tiger is larger and stronger. And is a better hunter than a male lion, males don’t hunt. But one thing alpha male lions do is fight to defend their pride. They fight other male lions a lot.

Tigers are usually isolated from other Tigers so don’t do much fighting if at all.

I believe the show said a Lion would most likely win based on their fighting experience.