It's been suggested that Bulgaria would be in a stronger position being on the defensive. And if so, and Bulgaria doesn't collapse, Romania and Turkey don't pile on. In that case - Enver Pasha doesn't lead Ottoman forces to the recapture of Thrace. That victory (coming after the disastrous defeat of the previous year) elevated Enver to the level of co-leader of the country. He was raised to the rank of pasha, and married a princess of the sultan's family.
No Thrace campaign, and Enver remains a second-tier player.