Pitcher.adjToIP() can cause data loss

[philosofool]

If the end user runs Pitcher.adjToIP(0) the all the attributes of the object are set to zero, after which it is impossible to recover the data. This would be bad. Pitcher.adjToIP() should follow Hitter.adjToPA() in not doing anything when zero is passed.

For me, this raises questions whether every object should store it's initial data and have a restore method that resets it to the state when it was initialized, but that's a future issue/discussion.