Yes, there is. To analyze how accurate your projections are, click on the "Analysis" tab at the top of the page. Data for analysis will be available around 3:00AM ET the following day for MLB/NBA/NHL and by Wednesday for NFL.
On this page, you will find a Pearson Correlation between actual results, your own uploaded projections, as well as other stats.
Pearson Correlation (r) is a measure of the correlation between sets of data to see how closely related they are. An r value between 0.5 and 1.0 indicates high correlation, where a higher r value indicates a higher correlation.
We can compare the Pearson Correlations between different sets of projections to see how closely related they are to actual player performance. By doing so, we have a useful measuring stick to indicate which projections are better than others. We can also learn how correlated different sets of projections are with each other.