I don't think the ratings you are using can be considered very accurate for the comparison you are making. Do the numbers used as Rasho's sampling come from the entire season, or during the same period which Nazr was on the team? If you are using Rasho's entire regular season numbers, then it's not an accurate comparison to Nazr's numbers, when he has only played for a few games during the end of the season.

Another point must be made due to the nature of the two players' playing time. When Nazr came to the team he did not take Rasho's place. He took Rose's place (or playing time). Not since Nazr has taken Rasho's starting role can you compare his performance to that of Rasho when he was starting. Rasho's numbers since he's been injured aren't really a valid comparison for Nazr now either. I think that both perceived +/- and stat based +/- comparisons between Rasho and Nazr must both be taken with a grain of salt. Either method of determining these players worth is based on either somewhat incomplete or uncomparable data.

I'm glad we did trade for Nazr. He has really started to come around and be an effective contributor for the Spurs. I also believe he has an upside in that he will only become better and more comfortable the more he plays within the Spurs system.