Random Forest performance measure

Hi anybody!

A short question: 

I've added the performance operator to my model with a RF algorithm. The accuracy percentage is 57%, however, this is very black and white as i'm predicting league outcome of the English Premier League (soccer ;-) )

Which parameter in the performance operator should I use to see how far the prediciton is from the correct answer?

Thus, if Chelsea was predicted 1st, but was should have been predicted 2nd.. how do i measure the performance of the model that it was not completely wrong but only by 1 place.

I thought to use the relative error, but the examples in my dataset are polynominal.

Any advice is welcome!

Thanx so much!

Frederique