If you are asking how he has screwed up this season, that is pretty easy to answer. On Tuesday he screwed up by not having Burnett ready to go in case they pinch hit, which they did. Last night he screwed up by not having Lowe or Williams start the 6th. Then when Lowe got in trouble, he should have gone with Williams in my opinion.
I think its laughable to say he hasn't made any good decisions since opening day. If the moves work they are good moves, if they don't then they were bad. He is using the same guys he used on opening day that pitched lights out against a good team that he is using now. The only difference is these guys aren't getting the outs. We have had threads here talking about how good Lowe looked in Cincy, well that didn't last long. That isn't on Scioscia. Jepsen had a 0 ERA going into Tuesday night, so I can understand leaving him in even though it didn't work. Someone said why not just leave Downs in to face Cespedes last night, I am sure if he would have allowed a game tying hit or a home run then that same someone would have blamed it on Scioscia. Its results that make you good or bad, and the same players that got him good results on opening day are giving him shit right now.
Now as for last night I completely disagree with him bringing in De La Rosa (I think that is his name) in that situation. Once again if I am going to speculate he brought him in because he thought he had a better chance of striking someone out. I personally wouldn't have put him in in that situation.