What is the probability that the parents will produce a short haired kitten

Well it depends on the parents

1 long haired parent + 1 short haired parent = 50% that you would get a short haired or long haired or even the off chance that you'll get a medium haired kitten

2 short haired parents = a almost definitely going to have a short haired kitten

2 long haired = will have a long haired kitten