In the exact same way, in cricket there is a style of bowling called legspin and bowlers who use that style have a particular type of ball called a “googly” which turns in the opposite direction to a normal legspin ball. Because legspinners sometimes have to do weird wrist contortions to get this ball to work, batsmen practise trying to “pick” this ball by noticing these tells (mainly whether they can see the back of the bowler’s hand).

So really crafty legspinners sometimes try to develop two versions of the googly: one with a deliberate tell and one without a tell.

Here’s an example of probably the greatest legspin bowler of all time doing exactly this, although with a different ball (a “flipper” or topspin ball) not a googly https://youtu.be/DlyG5wnW7I0?si=O463NAdV6NAAB3cG

Same thing happens in football with audibles. I wonder how many teams are feeding videos like these to AI and asking it to find patterns that might be tough for humans to see. If an AI thinks there's a pattern, verifying shouldn't be too hard either.