diff --git a/src/enc/histogram.c b/src/enc/histogram.c
index 286676e7..ea336781 100644
--- a/src/enc/histogram.c
+++ b/src/enc/histogram.c
@@ -214,10 +214,19 @@ static double InitialHuffmanCost(void) {
 
 // Finalize the Huffman cost based on streak numbers and length type (<3 or >=3)
 static double FinalHuffmanCost(const VP8LStreaks* const stats) {
+  // The constants in this function are experimental and got rounded from
+  // their original values in 1/8 when switched to 1/1024.
   double retval = InitialHuffmanCost();
+  // Second coefficient: Many zeros in the histogram are covered efficiently
+  // by a run-length encode. Originally 2/8.
   retval += stats->counts[0] * 1.5625 + 0.234375 * stats->streaks[0][1];
+  // Second coefficient: Constant values are encoded less efficiently, but still
+  // RLE'ed. Originally 6/8.
   retval += stats->counts[1] * 2.578125 + 0.703125 * stats->streaks[1][1];
+  // 0s are usually encoded more efficiently than non-0s.
+  // Originally 15/8.
   retval += 1.796875 * stats->streaks[0][0];
+  // Originally 26/8.
   retval += 3.28125 * stats->streaks[1][0];
   return retval;
 }