NAG zero is used for a null annotation; it is provided for the convenience of software designers as a placeholder value and should probably not be used in external PGN data.
NAGs with values from 1 to 9 annotate the move just played.
NAGs with values from 10 to 135 modify the current position.
NAGs with values from 136 to 139 describe time pressure.
Other NAG values are reserved for future definition.
Note: the number assignments listed below should be considered preliminary in nature; they are likely to be changed as a result of reviewer feedback.
NAG Interpretation --- -------------- 0 null annotation 1 good move (traditional "!") 2 poor move (traditional "?") 3 very good move (traditional "!!") 4 very poor move (traditional "??") 5 speculative move (traditional "!?") 6 questionable move (traditional "?!") 7 forced move (all others lose quickly) 8 singular move (no reasonable alternatives) 9 worst move 10 drawish position 11 equal chances, quiet position 12 equal chances, active position 13 unclear position 14 White has a slight advantage 15 Black has a slight advantage 16 White has a moderate advantage 17 Black has a moderate advantage 18 White has a decisive advantage 19 Black has a decisive advantage 20 White has a crushing advantage (Black should resign) 21 Black has a crushing advantage (White should resign) 22 White is in zugzwang 23 Black is in zugzwang 24 White has a slight space advantage 25 Black has a slight space advantage 26 White has a moderate space advantage 27 Black has a moderate space advantage 28 White has a decisive space advantage 29 Black has a decisive space advantage 30 White has a slight time (development) advantage 31 Black has a slight time (development) advantage 32 White has a moderate time (development) advantage 33 Black has a moderate time (development) advantage 34 White has a decisive time (development) advantage 35 Black has a decisive time (development) advantage 36 White has the initiative 37 Black has the initiative 38 White has a lasting initiative 39 Black has a lasting initiative 40 White has the attack 41 Black has the attack 42 White has insufficient compensation for material deficit 43 Black has insufficient compensation for material deficit 44 White has sufficient compensation for material deficit 45 Black has sufficient compensation for material deficit 46 White has more than adequate compensation for material deficit 47 Black has more than adequate compensation for material deficit 48 White has a slight center control advantage 49 Black has a slight center control advantage 50 White has a moderate center control advantage 51 Black has a moderate center control advantage 52 White has a decisive center control advantage 53 Black has a decisive center control advantage 54 White has a slight kingside control advantage 55 Black has a slight kingside control advantage 56 White has a moderate kingside control advantage 57 Black has a moderate kingside control advantage 58 White has a decisive kingside control advantage 59 Black has a decisive kingside control advantage 60 White has a slight queenside control advantage 61 Black has a slight queenside control advantage 62 White has a moderate queenside control advantage 63 Black has a moderate queenside control advantage 64 White has a decisive queenside control advantage 65 Black has a decisive queenside control advantage 66 White has a vulnerable first rank 67 Black has a vulnerable first rank 68 White has a well protected first rank 69 Black has a well protected first rank 70 White has a poorly protected king 71 Black has a poorly protected king 72 White has a well protected king 73 Black has a well protected king 74 White has a poorly placed king 75 Black has a poorly placed king 76 White has a well placed king 77 Black has a well placed king 78 White has a very weak pawn structure 79 Black has a very weak pawn structure 80 White has a moderately weak pawn structure 81 Black has a moderately weak pawn structure 82 White has a moderately strong pawn structure 83 Black has a moderately strong pawn structure 84 White has a very strong pawn structure 85 Black has a very strong pawn structure 86 White has poor knight placement 87 Black has poor knight placement 88 White has good knight placement 89 Black has good knight placement 90 White has poor bishop placement 91 Black has poor bishop placement 92 White has good bishop placement 93 Black has good bishop placement 84 White has poor rook placement 85 Black has poor rook placement 86 White has good rook placement 87 Black has good rook placement 98 White has poor queen placement 99 Black has poor queen placement 100 White has good queen placement 101 Black has good queen placement 102 White has poor piece coordination 103 Black has poor piece coordination 104 White has good piece coordination 105 Black has good piece coordination 106 White has played the opening very poorly 107 Black has played the opening very poorly 108 White has played the opening poorly 109 Black has played the opening poorly 110 White has played the opening well 111 Black has played the opening well 112 White has played the opening very well 113 Black has played the opening very well 114 White has played the middlegame very poorly 115 Black has played the middlegame very poorly 116 White has played the middlegame poorly 117 Black has played the middlegame poorly 118 White has played the middlegame well 119 Black has played the middlegame well 120 White has played the middlegame very well 121 Black has played the middlegame very well 122 White has played the ending very poorly 123 Black has played the ending very poorly 124 White has played the ending poorly 125 Black has played the ending poorly 126 White has played the ending well 127 Black has played the ending well 128 White has played the ending very well 129 Black has played the ending very well 130 White has slight counterplay 131 Black has slight counterplay 132 White has moderate counterplay 133 Black has moderate counterplay 134 White has decisive counterplay 135 Black has decisive counterplay 136 White has moderate time control pressure 137 Black has moderate time control pressure 138 White has severe time control pressure 139 Black has severe time control pressure