Seriously, though, you also need to make sure that your pitching staff is set up properly. I let the AI set my staff at the start if the year, then traded the MR that was in the closer's role - a hotshot FA that blew four saves in the first month en route to a 7.72 ERA. I had a designated closer on staff that I started to use, but new officially put in the closer role in my pitching depth chart (unbeknownst to me, I thought I had). Anyways, a time comes where I have to sim the remainder of a game because I didn't have time to finish. My team was in a save situation, and my #1 setup guy came on to get the save, while my "closer" pitched parts of the 7th and 8th. Also, keep in mind that fatigue plays a factor in the AI decision makig process.
With all that said, it probably is still a little broken, and I hope it gets fixed.
