--early_terminate

--early_terminate num (default = 3)
to save best model across passes. This is built upon the holdout validation part.

Whenever holdout validation is on, early termincation is on. The argument num is to specify, vw terminates if for  num of passes the validation loss does not decrease. Use --holdout_off to turn it off.

If filenames for output files are not empty (--invert_hash for gd, --output_feature_regularizer_binary and --output_feature_regularizer_text for bfgs, --readable_model and -f for both), the related models are saved when the after the pass where the best validation loss appeared.

For example:
(1)--passes 1000 --f model_best --holdout_off: The program will run 1000 passes and model is saved at the end.
(2)--passes 1000 --early_terminate 5 : The best-so-far model might be saved after pass 5. Then for pass 6-10, if the holdout validation loss never decreases, the learner terminates. So vw only runs for 10 passes, instead of 1000. Note that holdout validation is on in this case.