Jayadratha was very effective in stopping four of the five pandavas from entering Chakravyūha (by making use of a boon granted to him by Lord Shiva); Abhimanyu was very effective in holding all the Kaurava Mahārathis (Great Charioteers, colloquially 'Great Warriors') at bay and thereby preventing the advancement of Kaurava forces towards the Pandavas.
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The Chakravyūha or Padmavyūha was a special formation (Vyūha), and knowledge of how to penetrate it was limited to only a handful of warriors on the Pandavas' side, namely Abhimanyu, Arjuna, Krishna and Pradyumna.