Is there a change in mastery system?

So I'm pretty low in league, I'm relatively new. I just hit level 30 yesterday. After the update I think the mastery has changed a bit? I'm not too bad at Janna for my level and played a came and got a C. Now my kda was 1-4-3 which is pretty bad but I had a vision score around 61 and a crowd control around 53. I also had around 4k in ally shielding and 4k around in healing. I also won lane and I only ended up with a bad kda because the enemy top was yasuo and when I first fought him his q did more damage than my max health, so that ended pretty quickly after and we lost. But I dont think a 61 vision score with 53 crowd control even with 1 4 3 would have gotten me C earlier. Has there been a change? Also while you're at it can someone tell me how to deal with yasuo's infinite jump and infinite damage?