I believe they yell "bota" (boat-ah) which according
to the ole' google translation is:
BOTA -
v. launch; (Latin America) throw away, dispose of; throw, cast; bounce; lose
There is also a guy at Miami Jai Alai who likes to yell:
"El mango esta podrido" - the mango is rotten
"aguacate" - avocado
"Adios Lola" - goodbye Lola
and there was a guy at Dania for years that was nicknamed the
'spirit man' who used to slap the floor and the wall
while asking the spirit to help him win points...there is youtube
of him here:
http://www.youtube.com/watch?v=-VHqBfa833E
