Add rank & files labels by https://github.com/nguyenpham/Stockfish.

See PR @ official-stockfish#2723

src/Makefile

@@ -817,26 +817,26 @@ icc-profile-make:
 ### Bluefish-FD-dev-050320.exe.bench:Nodes searched  : 9724222
 ### Bluefish-FD-dev-050320.exe.bench:Nodes/second    : 2308146
 ### Blue-Honey-dev-050320.exe.bench:Nodes searched  : 4515734
-### Based on commits through 06/07/2020:
+### Based on commits through 06/08/2020:
 ### ======================================================
 ### Black-Diamond-XI-r2.exe.bench:Nodes searched  : 9423812
-### Black-Diamond-XI-r2.exe.bench:Nodes/second    : 2440137
+### Black-Diamond-XI-r2.exe.bench:Nodes/second    : 2340738
 ### Bluefish-FD-XI-r2.exe.bench:Nodes searched  : 9750552
-### Bluefish-FD-XI-r2.exe.bench:Nodes/second    : 2475387
+### Bluefish-FD-XI-r2.exe.bench:Nodes/second    : 2444972
 ### Bluefish-XI-r2.exe.bench:Nodes searched  : 5056003
-### Bluefish-XI-r2.exe.bench:Nodes/second    : 2426105
+### Bluefish-XI-r2.exe.bench:Nodes/second    : 2391675
 ### Blue-Honey-FD-XI-r2.exe.bench:Nodes searched  : 11242357
-### Blue-Honey-FD-XI-r2.exe.bench:Nodes/second    : 2538924
+### Blue-Honey-FD-XI-r2.exe.bench:Nodes/second    : 2557987
 ### Blue-Honey-XI-r2.exe.bench:Nodes searched  : 4297035
-### Blue-Honey-XI-r2.exe.bench:Nodes/second    : 2383269
+### Blue-Honey-XI-r2.exe.bench:Nodes/second    : 2431825
 ### Honey-FD-XI-r2.exe.bench:Nodes searched  : 9639894
-### Honey-FD-XI-r2.exe.bench:Nodes/second    : 2467339
+### Honey-FD-XI-r2.exe.bench:Nodes/second    : 2507776
 ### Honey-XI-r2.exe.bench:Nodes searched  : 4661118
-### Honey-XI-r2.exe.bench:Nodes/second    : 2488584
+### Honey-XI-r2.exe.bench:Nodes/second    : 2460991
 ### Stockfish-FD-XI-r2.exe.bench:Nodes searched  : 13771708
-### Stockfish-FD-XI-r2.exe.bench:Nodes/second    : 2344918
+### Stockfish-FD-XI-r2.exe.bench:Nodes/second    : 2331027
 ### Stockfish-XI-r2.exe.bench:Nodes searched  : 4582693
-### Stockfish-XI-r2.exe.bench:Nodes/second    : 2450637
+### Stockfish-XI-r2.exe.bench:Nodes/second    : 2459845
 ### Weakfish-XI-r2.exe.bench:Nodes searched  : 7134572
-### Weakfish-XI-r2.exe.bench:Nodes/second    : 3363777
+### Weakfish-XI-r2.exe.bench:Nodes/second    : 3306103
 ### ======================================================

src/Makefile.bak

@@ -817,26 +817,26 @@ icc-profile-make:
 ### Bluefish-FD-dev-050320.exe.bench:Nodes searched  : 9724222
 ### Bluefish-FD-dev-050320.exe.bench:Nodes/second    : 2308146
 ### Blue-Honey-dev-050320.exe.bench:Nodes searched  : 4515734
-### Based on commits through 06/06/2020:
+### Based on commits through 06/07/2020:
 ### ======================================================
 ### Black-Diamond-XI-r2.exe.bench:Nodes searched  : 9423812
-### Black-Diamond-XI-r2.exe.bench:Nodes/second    : 2437613
-### Bluefish-FD-XI-r2.exe.bench:Nodes searched  : 41989557
-### Bluefish-FD-XI-r2.exe.bench:Nodes/second    : 2539434
-### Bluefish-XI-r2.exe.bench:Nodes searched  : 17920048
-### Bluefish-XI-r2.exe.bench:Nodes/second    : 2532868
-### Blue-Honey-FD-XI-r2.exe.bench:Nodes searched  : 34869659
-### Blue-Honey-FD-XI-r2.exe.bench:Nodes/second    : 2577401
-### Blue-Honey-XI-r2.exe.bench:Nodes searched  : 16118357
-### Blue-Honey-XI-r2.exe.bench:Nodes/second    : 2532739
+### Black-Diamond-XI-r2.exe.bench:Nodes/second    : 2440137
+### Bluefish-FD-XI-r2.exe.bench:Nodes searched  : 9750552
+### Bluefish-FD-XI-r2.exe.bench:Nodes/second    : 2475387
+### Bluefish-XI-r2.exe.bench:Nodes searched  : 5056003
+### Bluefish-XI-r2.exe.bench:Nodes/second    : 2426105
+### Blue-Honey-FD-XI-r2.exe.bench:Nodes searched  : 11242357
+### Blue-Honey-FD-XI-r2.exe.bench:Nodes/second    : 2538924
+### Blue-Honey-XI-r2.exe.bench:Nodes searched  : 4297035
+### Blue-Honey-XI-r2.exe.bench:Nodes/second    : 2383269
 ### Honey-FD-XI-r2.exe.bench:Nodes searched  : 9639894
-### Honey-FD-XI-r2.exe.bench:Nodes/second    : 2511697
+### Honey-FD-XI-r2.exe.bench:Nodes/second    : 2467339
 ### Honey-XI-r2.exe.bench:Nodes searched  : 4661118
-### Honey-XI-r2.exe.bench:Nodes/second    : 2470120
+### Honey-XI-r2.exe.bench:Nodes/second    : 2488584
 ### Stockfish-FD-XI-r2.exe.bench:Nodes searched  : 13771708
-### Stockfish-FD-XI-r2.exe.bench:Nodes/second    : 2277444
+### Stockfish-FD-XI-r2.exe.bench:Nodes/second    : 2344918
 ### Stockfish-XI-r2.exe.bench:Nodes searched  : 4582693
-### Stockfish-XI-r2.exe.bench:Nodes/second    : 2490594
+### Stockfish-XI-r2.exe.bench:Nodes/second    : 2450637
 ### Weakfish-XI-r2.exe.bench:Nodes searched  : 7134572
-### Weakfish-XI-r2.exe.bench:Nodes/second    : 3397415
+### Weakfish-XI-r2.exe.bench:Nodes/second    : 3363777
 ### ======================================================

src/bitboard.cpp

@@ -240,9 +240,10 @@ const std::string Bitboards::pretty(Bitboard b) {
   {
       for (File f = FILE_A; f <= FILE_H; ++f)
           s += b & make_square(f, r) ? "| X " : "|   ";
-
-      s += "|\n+---+---+---+---+---+---+---+---+\n";
+// rank and file notation by nguyenpham https://github.com/official-stockfish/Stockfish/pull/2723
+      s += "| " + std::to_string(1 + r) + "\n+---+---+---+---+---+---+---+---+\n";
   }
+  s += "  a   b   c   d   e   f   g   h\n";
 
   return s;
 }

src/position.cpp

@@ -65,10 +65,11 @@ std::ostream& operator<<(std::ostream& os, const Position& pos) {
       for (File f = FILE_A; f <= FILE_H; ++f)
           os << " | " << PieceToChar[pos.piece_on(make_square(f, r))];
 
-      os << " |\n +---+---+---+---+---+---+---+---+\n";
+      os << " | " << (1 + r) << "\n +---+---+---+---+---+---+---+---+\n";
   }
-
-  os << "\nFen: " << pos.fen() << "\nKey: " << std::hex << std::uppercase
+// rank and file notation by nguyenpham https://github.com/official-stockfish/Stockfish/pull/2723
+  os << "   a   b   c   d   e   f   g   h\n"
+     << "\nFen: " << pos.fen() << "\nKey: " << std::hex << std::uppercase
      << std::setfill('0') << std::setw(16) << pos.key()
      << std::setfill(' ') << std::dec << "\nCheckers: ";