What games in your experience are the best at yielding plausible historically alternate results? I find that most of the turn-based games I play tend to end with the historical outcome. Sometimes the outcome varies in terms of date/time and cost, but the objectives are usually either accomplished, or not, along historical lines. I'm talking mostly about games by HPS/WDS, Slitherine/Matrix titles (ie. Operational Art of War and the Grigsby titles, etc.). Hearts of Iron seems to often times lead to results that depart from the historical timeline and outcome, but its hard for me to discern whether this is due more the strategy employed by the player or the unorthodox decision making of the AI.
Of course, there are games and scenarios that focus solely on alternate history or "what ifs", such as WDS Operation Sealion, or maybe some scenarios that model the invasion of say, Malta. What are some of the best titles or scenarios that approach these alternate strategies or operations that historically were never attempted or explored?
I used to always enjoy Avalon Hill's "3rd Reich" because it allowed for deviations in the historical narrative that were interesting, even if not historically accurate or plausible, but were interesting "what ifs", and thought that this characteristic made it an entertaining game, with lots of replayability. Germany could invade Spain and try to take Gibraltar, while the USSR could go after Turkey in 1940. Not necessarily realistic, but it made for a interesting and fun game.
I guess one of the problems is that to be generally considered a good historical game, it needs to be able to generate a realistically historical outcome "on average". I guess this somewhat straightjackets the designer as to what options he can implement in the game, to avoid giving it unrealistic outcomes. Therefore I've tended to gravitate towards games on the PC such as the Decisive Campaign series, which broadly follow the historical path, but allow the player to grade himself against the historical outcome.
On the other hand, one of the reasons I find myself playing more board games is that I find they generally have a more sandbox feel to them, and whilst they try & conform to history, their more abstract approach lends itself to non-historical outcomes as well. A case in point is Fleet Commander Nimitz - its a great game but has attracted some flak due to the potential ahistorical behaviour of the Japanese. However, the fact that the Japanese behaviour is to a degree random IMO adds to the enjoyment of the game and in some respects makes the game feel more realistic because, as the actual Allied commander, not knowing what the Japanese were planning was part of the challenge.
Sorry I can't point to any games to scratch your particular itch, but that's my two-pennyworth.
Paradox sandbox games are actually pretty good in this respect. For example, in HOI IV, the Japanese can oust the authoritarians and become more democratic.
These games generally give semi-realistic alternatives to history. The games I am thinking of are:
Hearts of Iron IV
Victoria 3
Europa Universalis IV
Crusader Kings III
Honorable mention to the "Making History" games by Factus (formerly Muzzy Lane). These games can be a wild ride historically sometimes. But I always felt they were a little too far out there. In one game I played, the AI Nationalist Chinese joined Germany and helped the Germans invade France. Sorry, I lost all suspension of disbelief in that one.
I like playing the Modern Campaigns from WDS. No history to guide your play and you can use the strategy that you think would work best. Playing a PBEM game from Danube '85 that is the entire campaign from Denmark to Austria. Right now the Leopards and M1's of NATO are stopping me cold in places but to do so they are having to concentrate which has left other forces room to roam. Going to be an intersting game. Also playing the full campaign from Korea '85. I'm playing as the NK and we have torn the ROK fortifications on the cease fire line apart and have encircled and destroyed a lot of troops. I've been adamant about finding and destroying Allied artillery as they are great killers in this game. Racing against the clock to keep troops reformed and rested but still moving forward to get as much ground as possible for the American reinforcements start pouring in. Of course I'll have the opportunity to take Chinese reinforcements later on.
I've always thought the Total War series generated alternate history plausibilities better than Paradox's EUROPA and CLAUSWITZ engines, where you can get completely weird situations like Haiti declaring war on an interior Russian tribe -- and worse, actually having a diplomatic resolution in favor of one or the other side gaining territory! Haven't kept up on the 4th generation Paradox stuff.
The Panther Games engine, now being used in the Command Ops 2 series, allows more focused and plausible what-if results, due to operational constraint, combined with lots of detail under the hood. But when I seriously started playing around with it, I soon noticed weird AI choices like sending a motorized company way of the way of its regiment crossing a river that shouldn't have given it nearly as much trouble; or the AI ganging a bunch of its units near the map's victory exit point where I could drive them out with artillery storms and assaults causing them to surrender instead of WINNING BY EXITING THE MAP leaving me in control of the AI's exit target.
I suppose the best alt-history games really need human competition because the AI doesn't really think at all so is only giving an illusion of thought about what's going on, even regarding parameters assigned and designed for it by actual thinking entities -- parameters which the AI cannot really understand only reactively aim for.