I have a few thoughts about why to breed during normal (winter months) breeding season. This is the natural season for ball pythons, and they normally go off feed during this season, and eat during non-breeding season (summer).

I noticed last season that a few females that were too small in the beginning of the breeding season produced follicles during the winter breeding season; although, they were never bred or even introduced to males. This led me to believe that this is when the females naturally produce follicles.

Females normally go off feed during winter and start eating again during summer. If I were to breed them during summer, then they may not eat after they laid since they normally do not eat during the winter season.