From bbe338b9fcab3ee7f071303ca35956ad667cc6b2 Mon Sep 17 00:00:00 2001
From: Tomasz Sobczyk <tomasz.sobczyk1997@gmail.com>
Date: Thu, 25 Mar 2021 14:00:00 +0100
Subject: [PATCH] Add random move accuracy for comparison.

---
 src/learn/learn.cpp | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/src/learn/learn.cpp b/src/learn/learn.cpp
index e17537ff..cf19bcc2 100644
--- a/src/learn/learn.cpp
+++ b/src/learn/learn.cpp
@@ -616,7 +616,8 @@ namespace Learner
             const PSVector& psv,
             Loss& test_loss_sum,
             atomic<double>& sum_norm,
-            atomic<int>& move_accord_count
+            atomic<int>& move_accord_count,
+            atomic<double>& sum_one_over_move_count
         );
 
         bool has_depth1_move_agreement(Position& pos, Move pvmove);
@@ -931,6 +932,12 @@ namespace Learner
         // search matches the pv first move of search(1).
         atomic<int> move_accord_count{0};
 
+        // If there is 10 legal moves then 0.1 will be added.
+        // This happens for each position tested.
+        // Effectively at the end we have the random move accuracy
+        // multiplied by the number of positions, which is psv.size()
+        atomic<double> sum_one_over_move_count{0.0};
+
         auto mainThread = Threads.main();
         mainThread->execute_with_worker([&out](auto& th){
             auto& pos = th.rootPos;
@@ -949,7 +956,8 @@ namespace Learner
                 psv,
                 test_loss_sum,
                 sum_norm,
-                move_accord_count
+                move_accord_count,
+                sum_one_over_move_count
             );
         });
         Threads.wait_for_workers_finished();
@@ -968,6 +976,7 @@ namespace Learner
 
             out << "  - norm = " << sum_norm << endl;
             out << "  - move accuracy = " << (move_accord_count * 100.0 / psv.size()) << "%" << endl;
+            out << "  - random move accuracy = " << (sum_one_over_move_count * 100.0 / psv.size()) << "%" << endl;
         }
         else
         {
@@ -983,10 +992,12 @@ namespace Learner
         const PSVector& psv,
         Loss& test_loss_sum,
         atomic<double>& sum_norm,
-        atomic<int>& move_accord_count
+        atomic<int>& move_accord_count,
+        atomic<double>& sum_one_over_move_count
     )
     {
         Loss local_loss_sum{};
+        double local_sum_one_over_move_count = 0.0;
         auto& pos = th.rootPos;
 
         for(;;)
@@ -1022,8 +1033,11 @@ namespace Learner
             // Threat all moves with equal scores as first. This is up to move ordering.
             if (has_depth1_move_agreement(pos, (Move)ps.move))
                 move_accord_count.fetch_add(1, std::memory_order_relaxed);
+
+            local_sum_one_over_move_count += 1.0 / static_cast<double>(MoveList<LEGAL>(pos).size());
         }
 
+        sum_one_over_move_count += local_sum_one_over_move_count;
         test_loss_sum += local_loss_sum;
     }