This is the trigger count for the switch's Dynamic Cut State trend algorithm -- once the calculated trend of CRC-type events on a port exceeds this many occurrences, the port switches from cut-through to store-and-forward mode. An admin tunes it to make the automatic protection more or less sensitive to a link that's degrading gradually rather than failing outright. The factory default is 8 events, but an admin on a very noisy legacy Token-Ring segment might raise it toward the 100 maximum to avoid constant mode-flapping.