First, the function he gave wasn't particularly weird; it's a pretty standard thing. Second, the value resultant from said function is independent of the lengt

First, the function he gave wasn't particularly weird; it's a pretty standard thing. Second, the value resultant from said function is independent of the length of the word, which is exactly the sort of thing you want with a hash function. If you have a hash space large enough to hold the longest English word converted to base 26, then you might still need to be concerned with clustering properties. It's considered undesirable to have large stretches within the hash space with no associated key; my understanding is that this somehow impairs the distribution from the modulus step in most hashtable implementations.