Oh the memories on ITF Bucharest from a couple of years ago.
Cadantu serving in the final tiebreak against Halep:
Underarm serve on MP - double faulting.
Pity no one made a video out of it.
In my native language they say:
A L' E' INUTIL INSEGNA' AL MUS, SI PIART TIMP E IN PLUI SI INFASTIDIS LA BESTIE!!
(translated) There is no gain in teaching the donkey, you waste your time and annoy the beast