For those interested in this stuff, I'd highly recommend a listen to Chris B. Brown on communication in football. How do teams call plays? What are the different systems for no-huddle play calling? Very cool.
https://www.solidverbal.com/2018/03/20/chris-b-brown-football-communication/
Some of my takeaways:
1) A problem that Chip Kelly had in the NFL was that he wasn't able to use audibles. Because of his uptempo system and the fact that there were multiple play signallers, there was no way to communicate an audible.
2) 35 min. mark, talks about how Gary Patterson calls his defensive plays with special trips calls. And there's a very amusing story about a major tell Patterson had.
3) Another problem is for up-tempo teams, how do you call the play right/left? Because with your uptempo play calls you need to be shorter and more concise, calling the direction of a run play or protection without giving it away can be a challenge. If its always, for example, Xray/Zebra the other team can quickly figure that out.
