I won the Premier League's first analytics hackathon (at Man City, 2016, IIRC), and all we did was some regression using some data that nobody had really looked at in detail before.

Back then, it was relatively easy to just look around and prod relatively available data and find new angles if you went in eyes open. If you were trying to justify spending all that money on that kid who isn't working out with you, the approach lets you dig the hole you want.