Model summarizing the contributions of various mechanisms to correct microtubule attachment defects during cell division. Unattached kinetochores are captured during phase 1, and erroneous attachments, such as merotely, are produced when the kinetochore orientation effect is compromised. Aurora B activity corrects merotely by promoting microtubule destabilization, leading to unattached kinetochores. The spindle assembly checkpoint (SAC) prevents the segregation of unattached kinetochores. Aurora B–like activity and the kinetochore orientation effect also promote a reduction in the number of microtubules attached to the wrong pole, leading to unbalance forces at the merotelic kinetochore in anaphase. These unbalance forces are sufficient to promote correction in anaphase and proper cell division. On the contrary, if no correction occurs, the cytokinetic actin ring traps the merotelic chromosome during cell division, leading to aneuploidy. Therefore, a combination of Aurora B–like activity, the kinetochore orientation effect, and SAC promotes kinetochore biorientation and proper cell division.