Back in April I looked at how someone could use a wargame (Gettysburg '88) to evaluate an author's theory (Tom Carhart in "Lost Triumph") that Lee had a secret plan to coordinate Pickett's Charge with a attack on the rear of the Federal Army by Stuart's cavalry. Carhart's theory is that Lee's brilliant plan was undone by the Boy General Custer and his unexpectedly effective resistance during the cavalry battle on Low Dutch Road on July 3rd, 1863.
I concluded back then that the wargame didn't suggest that the scheme was workable, but noted that few Gettysburg wargames allow players to really look at that end of the field.
A newer game that indirectly allows a look at the prospects for Lee's alleged plan is Columbia Games' Gettysburg: Badges of Courage. While not including the Low Dutch Road area, an optional rule allows for an off-map cavalry battle that could, conceivably, allow some of Stuart's troopers to arrive at 4 p.m., around the time of Pickett's attack.
Chances are so low that this will happen, though, that player's interested in the notion will have to tweak the Day 3 scenario somewhat.
Instead of playing the Cavalry battle exactly as written, player's can goose Stuart's chances by implementing the following measures: Assume Huey doesn't arrive and assume Custer stays with Kilpatrick's Division instead of joining Gregg. Add Jenkins to the off-board CSA cavalry force. Playing this out, though, will still reveal that Stuart's surviving force, if it can defeat Gregg, will often be too weak to attack the Union rear.
So as an alternative, there's the "Lost Triumph" variant, or Carhart's Fantasy scenario. Assume that Huey doesn't arrive and Custer is assigned to Gregg, but assume that the Union player rolls really, really bad and Custer, Gregg and McIntosh's brigades, Robertson's guns and the Gregg divisional leader are all eliminated while the Rebels just lose Jenkins in the fighting. Have Stuart, Beckham, Hampton, F.Lee and Chambliss arrive on the Baltimore Pike at full strength. In addition, on the 4 p.m. turn no Federal units within 2 hexes Powers Hill can move.