 <p>I think its reasonable to say that most algorithms have a best and a worst case. If you think about algorithms in terms of Asymptotic Analysis you can say that a O(n) search algorithm will perform worse than a O(log n) algorithm. However if you provide the O(n) algorithm with data where the search item is early on in the data set and the O(log n) algorithm with data where the search item is in the last node to be found the O(n) will perform faster than the O(log n).</p> <p>However an algorithm that has to examine each of the inputs every time such as an Average algorithm won't have a best/worst as the processing time would be the same no matter the data.</p> <p>If you are unfamiliar with Asymptotic Analysis (AKA big O) I suggest you learn about it to get a better understanding of what you are asking.</p>