Final answer:
The Battle of Ankara encouraged the development of the Janissary system because it highlighted the unreliability of the Turkish nobility in battle, making the loyal Janissaries even more vital to the Ottoman military structure.
Step-by-step explanation:
The effect of the Battle of Ankara on the Janissary system was significant as it demonstrated the unreliability of the Turkish nobility for defense purposes. This unreliability was evidenced by Bayezid I's nobles who fled and abandoned him to the Mongols during the battle. As a result, this event encouraged the Ottoman sultans to further develop the Janissary system, reinforcing their status as an elite infantry force directly loyal to the Sultan.
The Janissaries, who were expected to be unquestioningly loyal to their master, saw enhancements in their role and privileges following the battle since they were perceived as more dependable than noble vassals. This reliability stemmed from their unique position—they were cut off from their biological families and entirely dependent on the sultans, thus their loyalty was less likely to be compromised. Hence, the Battle of Ankara indirectly strengthened the Janissary system rather than leading to its dissolution or reducing its influence in the Ottoman military hierarchy.