Sourdough French Loaf

I made a French bread size loaf from a sourdough baguette recipe. It's a recipe I got in a sourdough class that I make regularly but usually in typical baguette form. It has about 50grams of starter and 2 gram sof commercial yeast for a 900 gram total dough. We are having roast beef melt sandwiches for dinner so I made some larger loaves than normal. I did everything I thought would decrease oven spring. I used a lower oven temperature, bulk and proofed longer than normal and held my lame completely vertical. Between Charlotte and the commerical yest, the end result was among the best oven spring I have had in a loaf. Not sure how it happened but will have to keep experimenting and learning. Bread baking is so complex.

Thanks for reading.