Help understanding scoring

One variable that's tricky to control for is shaping. If you did a better job shaping the more-successfully-scored loaf, that could explain part of the difference.

David has a point about shaping and that's likely one of the most important factors, but it's much more than that. Your levain strength, the structure you've build up, the technique used and how far along the fermentation process these breads were all impact the oven spring you'll get.  Make sure you're levain is very active, used at the right time, in the right proportion. Make sure that you bulk and then proof in the right proportion for your ambient room temp, recipe and schedule. Make sure that you develop proper structure when developing it during bulk through the proper use of coil folds, stretch and folds, etc. And make sure you find the sweet spot for when to bake along the final proof development.. there's no single silver bullet answer here. And oh, also the scoring technique itself plays an important role. It's just about practice, thoughtful reflection (and notes) about what works and what doesn't, and eventually you'll find it all comes into play.. good luck! frank!