When his son demonstrates prodigious Connect 4 skills, a father who was always second-best reconnects with his hyper-competitive family to train the boy and regain the title he lost from their fierce rival family in the quadrennial competition

Agreed with all the above comments.

I'll add that the wording in the logline is confusing - the chain of events is vague.
As you mention two families in the one sentence, it's not immediately clear which is which. Secondly, the use of so many adjectives reduces their individual values. Often when the premise isn't generating enough conflict or high enough stakes, the writer uses adjectives as a means to boost the impact of the individual components. And this logline has that very same problem.

At first glance -- and that is the most attention one can usually expect from a logline -- the stakes seem to be? for small potatoes. And the father's goal is selfish -- he aims to triumph vicariously through his son. Well, it's a comedy and what are comedies about, if not to play out the folly of human behavior?

Still, I'm not sure how credible the objective goal is.? My understanding is that Connect 4? is a solved game; that is, all the combination of moves have been analyzed.? It's been established that? whoever goes first has an unbeatable tactical advantage.? Like in? tic-tac-toe.? So the son can become a prodigy by merely googling the internet for the winning moves when he goes 1st.? (Unlike his father, who didn't that resource in his youth.) Where's the suspense?

fwiw

At first glance -- and that is the most attention one can usually expect from a logline -- the stakes seem to be? for small potatoes. And the father's goal is selfish -- he aims to triumph vicariously through his son. Well, it's a comedy and what are comedies about, if not to play out the folly of human behavior?

Still, I'm not sure how credible the objective goal is.? My understanding is that Connect 4? is a solved game; that is, all the combination of moves have been analyzed.? It's been established that? whoever goes first has an unbeatable tactical advantage.? Like in? tic-tac-toe.? So the son can become a prodigy by merely googling the internet for the winning moves when he goes 1st.? (Unlike his father, who didn't that resource in his youth.) Where's the suspense?

fwiw