These types of contests cannot be truly done by one individual unless that person is an expert in all the languages tested. We did a head to head at work once, and took the same set of requirements and two of us wrote the programs in two separate languages. First to meet all the requirements won. Trying to have the same programmer do the same thing just doesn't work since their biases and knowledge (or lack thereof) get in the way of the competition being fair. You tend to get the results you wanted in the first place.