I have discovered that if you acquire players via trade and/or shuttle players up and down from the farm and don't have all of the pitcher settings defined then the ROBOT does strange things.

For example, If there are three pitchers that do not have assigned roles then the ROBOT may do crazy things. This has happened to me recently.

Thus the ROBOT picks some strange starting pitchers and strange things happen. This situation does not necessarily point to TANKING.
It can point to NEGLECT (which can happen because of time constraints).