1. A system for determining the accuracy of automated valuation models (AVMs) that provide automated valuations for real estate properties, the system comprising: physical data storage configured to store (1) a reference valuation for a subject property and (2) a plurality of automated valuations of the subject property, each automated valuation of the subject property generated by an automated valuation model (AVM) without use of the reference valuation for the subject property, wherein different automated valuations correspond to different AVMs; and a computer system in communication with the physical data storage, the computer system comprising computer hardware, the computer system programmed to: calculate one or more indicators of accuracy for each AVM, the indicators of accuracy for each AVM based at least in part on the AVM's automated valuation of the subject property and the reference valuation of the subject property, wherein the AVM generates the automated valuation of the subject property before being updated with the reference valuation for the subject property, the reference valuation available to but not used by the AVM for the automated valuation; and determine a ranking of the plurality of AVMs based at least in part on the one or more indicators of accuracy.