There is very little evidence that I have seen that clutch performance (specifically performance w/RISP) is a skill. If it was, people would tend to remain clutch performers over a period of time, that their stats with RISP would be consistently higher than their overall stats year after year. Instead, we find the opposite. If you take the top 10% and bottom 10% clutch performers from one year and graph their clutch performance the following year, the two graphs would probably be similar. The majority in each group would have RISP performance about equal to their overall performance, some would be above, and some would be below.