Most of the time I have undergone instruction, as well as seen instruction I have been told to ensure the fingers are locked together, and then thumb pressed in against the hand. However, my question is when you see many people demonstrate a shuto uchi or uke (even by the same people who instructed you) and often people who are 'expert' in their art their fingers are slightly apart. Do you think this is because of relaxation of the hand, because it allows for a more effective strike/block, or what is your opinion and the application purpose?