title: Best Smoothing Function to use in nltk corpus_bleu method
body: <p>I'm trying to implement an Image Captioning model (CNN + LSTM) and as a validation metric I'm using the BLEU score. To be more precise, the corpus_bleu implementation of nltk.</p>
  <p>I tried using different SmoothingFunctions and I'm getting different values for the same candidate and reference.</p>
  <p>SmoothingFunction().method1 -&gt; 0025682587115391834</p>
  <p>SmoothingFunction().method2 -&gt; 0.01435390900932359</p>
  <p>SmoothingFunction().method3 -&gt; 0.005106152442970232</p>
  <p>Is there a &quot;default&quot; method that I should use or it depends on the task itself?</p>
  <p>Thanks in advance</p>