And then you could just also say 'what if the keeper guesses the right way to dive?' for when the pen-taker picks their corner and puts their foot through it.
FA cup final save vs City, the pen shootout against Liverpool and the penalty on Sunday against Ndiaye, Henderson just picks a corner and commits to the dive, he doesn't hesitate on any pen to wait for a stutter. Ndiaye does the right thing to wait for him. He gives himself away if you have the nerve to wait and look. Ndiaye hadn't even planted his left foot yet and the goalie has already shifted his weight to his right foot to dive to the bottom left corner.
Ndiaye has also shown that he mixes it up, the last pen he took before Sunday (against Arsenal) he doesn't hesitate at all, just runs straight up and slots it borrom right - that keeps goalies guessing.