To judge a prediction on your site at the moment I have to:

1) Click on the prediction in the list.
2) Click on the text field which contains the number
3) Switch to keyboard to type in the number and enter to affirm the prediction
4) Use the mouse again to get back to the prediction list

The second point could be saved by autofocusing on that field. You might also think of a way to provide buttons to allow people to enter data via mouse clicks.

It would also be nice to have a "next prediction"-button on prediction page to make it easier to enter a bunch of predictions.