Chakravyuh is a brilliant military tactical approach that only few warriors such as Drona, Krishna and Arjun knew to breach and break it. It involved large army formation in multiple layers requiring highest surviving skills to prevail. The warrior entering the layer must ensure he creates gap as wide as possible so that other soldiers doesn’t fill the gap. The warrior entering Chakravuyh must be able to create as much as panic as possible before he reached the inner most circle where experienced warriors stay. This requires great skills to breach the layers and break the Chakravuyh.
On 13th Day, Dronacharya formed the Chakravuyh to capture Yudhistir and end the war. Since Arjun was not present at this moment, Abhimanyu entered Chakravuyh and got killed. He knew how to enter the Chakravuyh but couldn’t know how to come out of this. Though was able to breach the layers and reach innermost circle, the onslaught from Kauravas warriors were highly demanding and he was unable to break it. Besides, the 4 pandavas were successfully stopped by Jayadratha from supporting Abhimanyu, he had a supreme power from Lord Shiva to defeat any warrior expect Arjun for one day.
Let’s assume, Arjun, the great archer along with Krishna, the great strategist had entered the Chakravuyh, perhaps the battle would have been completed that day. Even Jayadratha who stopped 4 pandavas with blessing from Shiva couldn’t have stopped Arjun. Jayadratha had blessing from Shiva on any one day he will win any warrior expect Arjun. Arjun knew how to enter and break the Chakravyuh. Arjun had divya astras than any warriors giving him enough fire power to overcome the Kaurava Warriors. With Krishna as his Charioteer, he must received all the advises causing massive destruction to Kauravas. Since Chakravuyh utilized large number of resources to be formed, it would presented a opportunity for Arjun and Krishna to exploit entire Kaurava armies.
Dronacharya knew Arjun very well can break the Chakravuyh hence planned Chakravuyh in a way that Arjun and Krishna would not be able to participate and kept both of them away from the battle to annihilate Pandavas and leveraged the one time supreme power of Jayadratha to win the day for Kauravas. Had Arjun entered Chakravuyh with Krishna, day would have seen different outcome with possibility of many Kauravas Warriors perishing that day.
Nevertheless, the outcome was turning point in the war since Abhimanyu’s death angered Pandavas and they used treacherous ways to kill key Kauravas such as Drona, Karna and Duryodhan.