diff --git a/src/lx_chess.cr b/src/lx_chess.cr
index f43dd7c..36858dd 100644
--- a/src/lx_chess.cr
+++ b/src/lx_chess.cr
@@ -8,10 +8,6 @@ options = {} of String => String | Nil
 OptionParser.parse do |parser|
   parser.banner = "Usage: lx_chess [fen]"
 
-  parser.on("--fen=FEN", "use fen string for board") do |fen_string|
-    options["fen_string"] = fen_string
-  end
-
   parser.on("-h", "--help", "Show this help") do
     puts parser
     exit
@@ -22,14 +18,26 @@ OptionParser.parse do |parser|
     exit
   end
 
+  parser.separator "\nGame options"
+
+  # parser.on("-e", "--eval", "Evaluate a given position") do
+  #   options["evaluate"] = "true"
+  # end
+
+  parser.on("-f FEN", "--fen=FEN", "use fen string for board") do |fen_string|
+    options["fen_string"] = fen_string
+  end
+
   parser.on("--board-theme=COLOR", "Set the board theme") do |color|
     options["theme"] = color
   end
 
-  parser.on("--open=PGN", "open a pgn file") do |path|
+  parser.on("-o PGN", "--open=PGN", "open a pgn file") do |path|
     options["pgn_path"] = path
   end
 
+  parser.separator "\nPlayer options"
+
   parser.on("--player-white=PLAYER", "set the type of player (human|computer)") do |player_type|
     case player_type
     when /c(omputer)?/i
@@ -44,6 +52,8 @@ OptionParser.parse do |parser|
     end
   end
 
+  parser.separator "\nDebugging options"
+
   parser.on("--log=FILE", "log to file") do |file_Path|
     options["log_file"] = file_Path
   end
diff --git a/src/lx_chess/computer.cr b/src/lx_chess/computer.cr
index 70cad74..35aeaa0 100644
--- a/src/lx_chess/computer.cr
+++ b/src/lx_chess/computer.cr
@@ -86,15 +86,15 @@ module LxChess
     # Generate an array of moves (from => to) which result in an even or best score
     # TODO: promotion, pruning
     def best_moves(game : Game, turn : Int8? = nil, depth = 0, root_tree : MoveTree? = nil) # : Array(Array(Int16))
-      turn = turn || game.turn
+      Log.debug { "=================================== Best moves ===================================" }
 
-      Log.debug { "Evaluating best moves for turn: #{turn}, depth: #{depth}..." }
+      turn = turn || game.turn
 
       if root_tree.nil?
         root_tree = MoveTree.new score: board_score(game, turn), turn: turn
       end
 
-      Log.debug { "Current Board score: #{root_tree.score}, turn: #{turn}" }
+      Log.debug { "Evaluating best moves for turn: #{turn}, depth: #{depth}, current score: #{root_tree.score} ..." }
 
       move_sets(game, turn).each do |set|
         origin = set.piece.index
@@ -109,17 +109,27 @@ module LxChess
         end
       end
 
-      Log.debug { "Considered #{root_tree.branches.size} moves at depth #{depth}" }
+      Log.debug { "\n" + root_tree.to_s(IO::Memory.new).to_s }
+
+      Log.debug { "Found #{root_tree.branches.size} moves" }
+      Log.debug do
+        current_bests = root_tree.best_branches.map { |b| [b[0], b[1]].map { |c| game.board.cord(c) }.join(" => ") }.join(", ")
+        "current best branches: #{current_bests}"
+      end
 
       if depth < 2
         root_tree.branches.each do |branch|
           from, to, tree = branch
-          Log.debug { "Considering #{game.board.cord(from)} => #{game.board.cord(to)} ..." }
+          Log.debug do
+            "Considering branch: #{game.board.cord(from)} => #{game.board.cord(to)} ..."
+          end
 
           game.tmp_move(from: from, to: to) do
             best_moves(game, turn, depth + 1, tree)
 
             if tree.score > root_tree.score
+              Log.debug { "Found better branch: #{game.board.cord(from)} => #{game.board.cord(to)} : #{root_tree.score} => #{tree.score}" }
+
               root_tree.score = tree.score
               root_tree.best_branches.truncate(0, 0)
             end
diff --git a/src/lx_chess/move_tree.cr b/src/lx_chess/move_tree.cr
index 16a65cc..c5fa595 100644
--- a/src/lx_chess/move_tree.cr
+++ b/src/lx_chess/move_tree.cr
@@ -33,5 +33,18 @@ module LxChess
 
       @branches << other
     end
+
+    def to_s(io = STDOUT, depth = 0)
+      if parent
+        io << parent.to_s(io)
+        io << "\n"
+        depth += 1
+      end
+      io << "Tree: score - " << @score << "\n"
+      @branches.each do |(from, to, tree)|
+        io << "  " << Board.cord(from) << " => " << Board.cord(to) << " : " << tree.score << "\n"
+      end
+      io
+    end
   end
 end