Vivek, I strongly disagree with you here because of the fact that the number variables are very fragile: they are global to every pattern match.

If someone else comes along and adds (for instance) a"harmless" subroutine call that sometimes does a pattern match of its own between the match and the usage of $1, then the results are unpredictable because the intervening match has reused the global variables.

If you always capture the value in a separate variable immediately, you're safe from this potential bug.