Here's what they wrote back for anyone curious:

"You have Connor listed at the top of your defensive replacement hierarchy, so he would never be replaced for defensive purposes. You would need to have a player ranked above him the hierarchy who's not already in the game."

This actually blows my mind, because it means I've been misinterpreting the Def Sub Hierarchies this whole time. I always thought your first player was your general starter, and whoever is behind him, is the Def Sub. That was my mistake I guess.

Thanks for posting this and kudos to site staff on the apparently fast reply.

It’s a good general reminder though of what was said above. the SIM engine never goes rogue and randomly decides to overrule your instructions. If something didn’t happen the way you thought it would, it almost always is a result of your settings.

That's actually really interesting. Had no idea that's how defensive sub hierarchy was used (I almost always turn off defensive subs entirely)

The Defensive Replacement hierarchy is just that, a hierarchy of who your preferred defensive replacements are. If your every day starter is the first player listed, then there is no defensive substitution made since the engine sees that your preferred choice is already in the game. I'm glad the explanation makes sense and there was no error in the process.

Posted by contrarian23 on 10/2/2018 2:22:00 PM (view original):
Thanks for posting this and kudos to site staff on the apparently fast reply.

It’s a good general reminder though of what was said above. the SIM engine never goes rogue and randomly decides to overrule your instructions. If something didn’t happen the way you thought it would, it almost always is a result of your settings.

I wish that were true. From a handful of support tickets, the most informative (but also pretty frustrating) response I've gotten was "The settings are a guideline that the engine tries to follow, but if there are competing restrictions, then it will disregard some settings." That particular answer was in response to my complaint about "Use Mopup Only When Losing" being ignored, together with the sim engine not seeming to care that I had "Use Closer in Save Situations Only" NOT set. It turns out the sim engine would rather disregard those settings and let the mopup pitcher turn a big lead into a save situation, than to bring in the closer with a big lead. ("The closer setting really means that the engine will prefer to use a closer in a tie game as well as a save situation. In a non-save situation like this, it would still prefer not to use up the closer.")

The other problem I've seen multiple times involves the player rest hierarchy being ignored, with DH lineups. Sometimes a starting DH who is not listed in the hierarchy for any fielding position gets used as a starter in the field anyway, despite the backups at that fielding position being rested and available. I've seen that on multiple teams over the years. I've only noticed it involving DH's, but it could be that they are the only ones to catch my attention when skimming boxscores.

The mop-up/closer thing has been known and documented in these forums for years. When those are your only 2 rested pitchers available, the SIM will often choose the mop-up, especially if the score is not close, regardless of settings. I agree it's technically a violation of settings, but:
(a) I think it's 100% consistent with how every major league manager would deal with the issue
(b) It's not "randomly deciding to overrule your instructions." It's very clearly built into the algorithm to do things that way, and it is applied consistently.

The DH thing is a legitimate complaint. I rarely play DH leagues and cannot recall an example of this happening to me, so I have no idea what's going on there.

Posted by skunk206 on 10/2/2018 4:27:00 PM (view original):
The Defensive Replacement hierarchy is just that, a hierarchy of who your preferred defensive replacements are. If your every day starter is the first player listed, then there is no defensive substitution made since the engine sees that your preferred choice is already in the game. I'm glad the explanation makes sense and there was no error in the process.

I find this interesting as well. What you said makes sense, but for some reason I always assumed WIS ignored those already in the game when it came to the hierarchy list. If I have a C/D 1B starting who happens to be at the top of my hierarchy, but his "Defensive replacement" box is checked and there's a B/A 1B right below him on the list, I always assumed WIS would make the change. Good info to have.