When you want to slightly disagree with someone's opinion or description, use the phrase "I wouldn't say ___ is ___" and then say your own opinion about it:

I wouldn't say it's necessary to have a college degree, although that does help.

Well, I wouldn't say he's the best player. He good, don't get me wrong, but I think there are a few others who are a bit better.

When you disagree in this way, it sounds like you're only slightly changing what the other person said, so it's a pretty polite phrase.