Day one continues. Rosencrans activates to push a small force of Bragg’s back successfully. Then the hard work of transitioning forces from South to North to counter the Confederate push there. The Union is plum caught flat footed here at the out set and must re orientate it self while simultaneously not exposing its Southern flank to devastating attacks from that direction.
The Confederates bring 127 SP to the party vs 100 for the Union. So the disparity is not huge IF the Union has good terrain and can avoid being flanked etc. Thomas’s Corps moves north. It is one of the strongest for the Union in terms of manpower. They race Hill who is on the other side of the Chattanooga stream. Two  rolls in a row for movement crush my fatigue levels and mean that we are in real trouble if we cannot recover prior to any further attacks. The battle is building to a head for late in Day 1 or possibly early Day 2 subject to the Confederate desire to attrite his army.