improve remaining guess estimation

src/lib/solver.rs

@@ -70,6 +70,14 @@ impl Solver {
         });
     }
 
+    fn estimate_guesses(&self, expected_information_gained: f64) -> f64 {
+        if self.possible_solutions.len() == 1 {
+            1.0
+        } else {
+            1.0 + self.possible_solutions.equal_likelieness_entropy() - expected_information_gained
+        }
+    }
+
     pub fn evaluate_word(&self, word: &str) -> WordStats {
         let solution_probability = self.possible_solutions.word_probability(word);
 
@@ -79,9 +87,7 @@ impl Solver {
 
         let expected_score_after_guess = score * solution_probability
             + (1.0 - solution_probability)
-                * (score
-                    + (self.valid_words.equal_likelieness_entropy() - expected_information_gained)
-                        .log2());
+                * (score + self.estimate_guesses(expected_information_gained));
 
         WordStats {
             word: word.to_string(),