Update README.md

README.md

@@ -31,7 +31,11 @@ Use the `-a` flag to evaluate a non-time-aligned transcription:
 * `-a` or `-A`: Perform normal (`-a`) or verbose (`-A`, will also print out note-by-note alignment details) alignment.
 
 * `-p DOUBLE` (new in v2.2): Set the DTW insertion and deletion penalties to the given `DOUBLE` (default 1.0).  
-Higher values will force the DTW alignment to align as many notes as possible, even if they don't match well. Lower values will make it only rarely align notes that don't match exactly.
+Higher values will be faster, but force the DTW alignment to align as many notes as possible, even if they don't match well.  
+Lower values will be slower, but make it only rarely align notes that don't match exactly.  
+The default of 1.0 should be good in most cases. Values of 0.5 and 1.0 are sort of inflection points
+(you will find large changes in the number of potential alignments around these values).  
+_NOTE: You should use the same value throughout your whole evaluation for a fair comparison._
 
 ### Aligned Data
 To evaluate a time-aligned transcription and ground truth: