An Incomplete Strasburg Shutdown Primer
Here is some of what we know about the Strasburg's innings limit. The ultimate innings cap appears to be 180 innings as Mike Rizzo told Yahoo Sports Jeff Passan that Strasburg will not exceed that number. We also know that the Nationals have a 50 page binder on how to handle Strasburg. The most important thing we know though is that this isn't exactly an innings limit, and while Mike Rizzo gave a number of 180 and Davey Johnson has recently said Strasburg will miss 3-4 starts at the end of the season no one outside of Mike Rizzo knows what Mike Rizzo is thinking and when he is going to pull the plug on Stephen Strasburg.
The Nationals are going to shut Strasburg down when they feel the signs of fatigue are enough that they are starting to creep into an area that risks injury. As far as what those signs could be one very well could be loss of command and if that is a sign then we are indeed inching closer and closer to the shutdown date. For the month of August Strasburg had a 2.91 K/BB ratio. His worst in any month of this season by far and off quite a bit from his season total of 4.23.
To counter that, there exists evidence that this could just be an off month with command. In five starts Strasburg walked 11 batters in May the exact same number he did in August in the same number of starts. Pitchers go through slumps just like batters, and while August was a great month for Strasburg with results it wasn't his best month with command.
Command will be only one of the factors the Nationals are looking at. Others will be velocity, arm slot, and release point. All of these factors are in some ways tied together and the two most important are the arm slot and the release point. When the arm slot starts to shift it means a pitcher is starting to compensate for being tired and will be using muscles and body parts foreign to their pitching motion and it is this that leads to injuries. As far as the velocity goes according to this chart it has held steady.
The Strasburg shutdown is a mystery to everyone but Rizzo. He will take the advice from Davey Johnson, his assistant GMs, Strasburg's doctor, and other's in the sports medicine arena that the Nationals have reached out to, but without direct access to Mike Rizzo's brain there is no way of knowing exactly when Strasburg will be shut down. Rizzo may not even know at this point. Last night when asked the question Davey Johnson said that after two or three more starts they would reevaluate the situation.
This could be how the Nationals have been doing it all season long. Dividing Strasburg's starts into quarters or some other subset and looking at how he has pitched, where his arm slot and release point are, how his velocity is, and how he is commanding each of his pitches. When the findings show that it is time to shut him down he will be shut down, and if the signs never show up will Rizzo back off from the 180 innings number. The only person that knows that is Mike Rizzo, but one thing can be certain, before he makes any decision of that magnitude he will be making a phone call to Dr. Lewis Yocum.