diff --git a/src/learn/gensfen.cpp b/src/learn/gensfen.cpp
index 65e64177..ec3de570 100644
--- a/src/learn/gensfen.cpp
+++ b/src/learn/gensfen.cpp
@@ -166,7 +166,7 @@ namespace Learner
                         output_file_stream.write(reinterpret_cast<const char*>(buf->data()), sizeof(PackedSfenValue) * buf->size());
 
                         sfen_write_count += buf->size();
-#if 1
+
                         // Add the processed number here, and if it exceeds save_every,
                         // change the file name and reset this counter.
                         sfen_write_count_current_file += buf->size();
@@ -186,7 +186,7 @@ namespace Learner
                             output_file_stream.open(new_filename, ios::out | ios::binary | ios::app);
                             cout << endl << "output sfen file = " << new_filename << endl;
                         }
-#endif
+
                         // Output '.' every time when writing a game record.
                         std::cout << ".";
 
@@ -519,10 +519,6 @@ namespace Learner
         {
             // Write out one sfen.
             sfen_writer.write(thread_id, *it);
-#if 0
-            pos.set_from_packed_sfen(it->sfen);
-            cout << pos << "Win : " << it->is_win << " , " << it->score << endl;
-#endif
         }
 
         return quit;
@@ -667,13 +663,12 @@ namespace Learner
 
         for (auto m : pv)
         {
-#if 1
             // There should be no illegal move. This is as a debugging precaution.
             if (!pos.pseudo_legal(m) || !pos.legal(m))
             {
                 cout << "Error! : " << pos.fen() << m << endl;
             }
-#endif
+
             pos.do_move(m, states[ply++]);
 
             // Because the difference calculation of evaluate() cannot be
@@ -803,19 +798,6 @@ namespace Learner
                     // Save the move score for adjudication.
                     move_hist_scores.push_back(search_value);
 
-#if 0
-                    dbg_hit_on(search_value == leaf_value);
-                    // gensfen depth 3 eval_limit 32000
-                    // Total 217749 Hits 203579 hit rate (%) 93.490
-                    // gensfen depth 6 eval_limit 32000
-                    // Total 78407 Hits 69190 hit rate (%) 88.245
-                    // gensfen depth 6 eval_limit 3000
-                    // Total 53879 Hits 43713 hit rate (%) 81.132
-
-                    // Problems such as pruning with moves in the substitution table.
-                    // This is a little uncomfortable as a teacher...
-#endif
-
                     // If depth 0, pv is not obtained, so search again at depth 2.
                     if (search_depth_min <= 0)
                     {
diff --git a/src/learn/learner.cpp b/src/learn/learner.cpp
index e7f021fe..2f1d27b2 100644
--- a/src/learn/learner.cpp
+++ b/src/learn/learner.cpp
@@ -1163,11 +1163,6 @@ namespace Learner
             if (ps.gamePly < prng.rand(reduction_gameply))
                 goto RETRY_READ;
 
-#if 0
-            auto sfen = pos.sfen_unpack(ps.data);
-            pos.set(sfen);
-#endif
-            // ↑ Since it is slow when passing through sfen, I made a dedicated function.
             StateInfo si;
             const bool mirror = prng.rand(100) < mirror_percentage;
             if (pos.set_from_packed_sfen(ps.sfen, &si, th, mirror) != 0)
@@ -1207,28 +1202,6 @@ namespace Learner
             // If it is the result of searching a completely different place, it may become noise.
             // It may be better not to study where the difference in evaluation values ​​is too large.
 
-#if 0
-            // If you do this, about 13% of the phases will be excluded 
-            // from the learning target. Good and bad are subtle.
-            if (pv.size() >= 1 && (uint16_t)pv[0] != ps.move)
-            {
-                //dbg_hit_on(false);
-                continue;
-            }
-#endif
-
-#if 0
-            // It may be better not to study where the difference in evaluation values ​​is too large.
-            // → It's okay because it passes the win rate function... 
-            // About 30% of the phases are out of the scope of learning...
-            if (abs((int16_t)r.first - ps.score) >= Eval::PawnValue * 4)
-            {
-                //dbg_hit_on(false);
-                continue;
-            }
-            //dbg_hit_on(true);
-#endif
-
             int ply = 0;
 
             // A helper function that adds the gradient to the current phase.
@@ -1315,17 +1288,6 @@ namespace Learner
             // rewind the phase
             for (auto it = pv.rbegin(); it != pv.rend(); ++it)
                 pos.undo_move(*it);
-
-#if 0
-            // When adding the gradient to the root phase
-            shallow_value = 
-                (rootColor == pos.side_to_move()) 
-                ? Eval::evaluate(pos) 
-                : -Eval::evaluate(pos);
-
-            dj_dw = calc_grad(deep_value, shallow_value, ps);
-            Eval::add_grad(pos, rootColor, dj_dw, without_kpp);
-#endif
         }
 
     }
@@ -2058,18 +2020,6 @@ namespace Learner
             learn_think.best_nn_directory = std::string(Options["EvalDir"]);
         }
 
-#if 0
-        // A test to give a gradient of 1.0 to the initial stage of Hirate.
-        pos.set_hirate();
-        cout << Eval::evaluate(pos) << endl;
-        //Eval::print_eval_stat(pos);
-        Eval::add_grad(pos, BLACK, 32.0, false);
-        Eval::update_weights(1);
-        pos.state()->sum.p[2][0] = VALUE_NOT_EVALUATED;
-        cout << Eval::evaluate(pos) << endl;
-        //Eval::print_eval_stat(pos);
-#endif
-
         cout << "init done." << endl;
 
         // Reflect other option settings.