Sleuthing the stone
When baking two bâtards or a few baguettes, I've noticed of late the bottom of the bread closest to the left side of my stone is much darker than the others. Almost black in a few spots, as if it was charred.
I have a natural gas oven, 14" x 16" x .5" stone (which is clean and in good shape), and have an oven thermometer on each side of of the stone. The thermometers read the same temperature, be it 500F or 460F. There's always a sheet of parchment between the bread and the stone.
When I steam my oven, I use ice cubes in a loaf pan with lava rocks on the left side of the oven and a broiler pan filled with lava rocks on the right side of the oven. I wondered if my new steaming method is having something to do with the excessive coloring on the left side. However, I get the same darkness on the bagel bottoms that sit at the top left side of the stone - and bagels aren't steamed. Actually, the steam pans are removed when I bake bagels.
No issues when I have just one bâtard or boule in the oven - but then, it's generally in the center of the stone.