Which card game requires the most skill?

Which card game requires the most skill? Bridge is always mentioned as the most skill-based card game. It could be said that all card games require at least some skill. However, there are card games where luck is a concluding factor.

Bridge is always mentioned as the most skill-based card game. It could be said that all card games require at least some skill. However, there are card games where luck is a concluding factor.