diff --git a/src/main/client/src/Game.jsx b/src/main/client/src/Game.jsx
index 50ea2e3..b06950a 100644
--- a/src/main/client/src/Game.jsx
+++ b/src/main/client/src/Game.jsx
@@ -46,7 +46,8 @@ export const Game = () => {
   let setGameState = useGameStore(state => state.setGameState)
   let queueStatus = useGameStore(state => state.queueStatus)
   let addMove = useGameStore(state => state.addMove)
-  let { board, currentColor, currentPlayer, counting, forbidden } = useGameStore(state => state.gameState)
+  let currentPlayer = useGameStore(state => state.currentPlayer)
+  let { board, currentColor, counting, forbidden } = useGameStore(state => state.gameState)
   let [forbidden_x, forbidden_y] = forbidden
   let initialized = useRef()
   let canvasRef = useRef()
@@ -117,7 +118,7 @@ export const Game = () => {
     if (!board.length) {
       return
     }
-    if (!counting && currentPlayer !== auth.name) {
+    if (!counting && currentPlayer() !== auth.name) {
       return
     }
     let cursor_x = Math.round((e.nativeEvent.offsetX - context.margin) / context.step)
@@ -146,7 +147,7 @@ export const Game = () => {
       if (cursor_x == forbidden_x && cursor_y == forbidden_y) {
         return
       }
-      if (currentPlayer !== auth.name) {
+      if (currentPlayer() !== auth.name) {
         return
       }
     }
@@ -173,7 +174,7 @@ export const Game = () => {
     } else {
       paintStones(context, board)
     }
-    if (currentPlayer !== auth.name) {
+    if (currentPlayer() !== auth.name) {
       return
     }
     if (!context.isCursorInBounds(cursor_x, cursor_y)) {
diff --git a/src/main/client/src/feature/GamePanel.jsx b/src/main/client/src/feature/GamePanel.jsx
index 267d220..b5d8eff 100644
--- a/src/main/client/src/feature/GamePanel.jsx
+++ b/src/main/client/src/feature/GamePanel.jsx
@@ -48,7 +48,8 @@ function Panel({zoom, setZoom}) {
   let auth = useAuthStore(state => state.auth)
   let black = useGameStore(state => state.black)
   let white = useGameStore(state => state.white)
-  let { board, currentPlayer, counting } = useGameStore(state => state.gameState)
+  let currentPlayer = useGameStore(state => state.currentPlayer)
+  let { board, counting } = useGameStore(state => state.gameState)
   let navigate = useNavigate()
   let onExit = useCallback(() => {
     navigate(base + "/lobby")
@@ -121,7 +122,7 @@ function Panel({zoom, setZoom}) {
       <div className="mt-2">
         <Button
           onClick={onPass}
-          disabled={counting || currentPlayer !== auth.name}>
+          disabled={counting || currentPlayer() !== auth.name}>
           Pass
         </Button>
       </div>
@@ -148,7 +149,7 @@ function Panel({zoom, setZoom}) {
       )}
       {!counting && (
         <div className="mt-2">
-          {currentPlayer + " ist dran..."}
+          {currentPlayer() + " ist dran..."}
         </div>
       )}
     </>
diff --git a/src/main/client/src/model/PointList.js b/src/main/client/src/model/PointList.js
index e335327..37c977b 100644
--- a/src/main/client/src/model/PointList.js
+++ b/src/main/client/src/model/PointList.js
@@ -7,11 +7,14 @@ export class PointList {
   static LO = 0xffff
   static HI = 0xffff0000
 
+  static EMPTY = {
+    size: () => 0,
+    forEach: () => undefined,
+    isEmpty: () => true,
+  }
+
   static empty() {
-    return {
-      size: 0,
-      forEach: () => {},
-    }
+    return PointList.EMPTY
   }
 
   constructor(dim) {
diff --git a/src/main/client/src/model/board.js b/src/main/client/src/model/board.js
index d74c7a6..3e49c03 100644
--- a/src/main/client/src/model/board.js
+++ b/src/main/client/src/model/board.js
@@ -18,7 +18,6 @@ export function getGroupInfo(board, xx, yy) {
     return {
       x: xx,
       y: yy,
-      ptId: yy * dim + xx,
       color: color,
       hasStone: false,
       liberties: 0,
@@ -80,7 +79,6 @@ export function getGroupInfo(board, xx, yy) {
   return {
     x: xx,
     y: yy,
-    ptId: yy * dim + xx,
     color: color,
     hasStone: true,
     liberties: liberties,
@@ -98,7 +96,7 @@ export function rehydrate(board) {
   for (let y = 0; y < board.length; y++) {
     for (let x = 0; x < board[y].length; x++) {
       if (result[y][x]) {
-        result[y][x] = {...result[y][x], x: x, y: y, ptId: y * dim + x }
+        result[y][x] = {...result[y][x], x: x, y: y}
         continue
       }
       let groupInfo = getGroupInfo(board, x, y)
diff --git a/src/main/client/src/model/ko.js b/src/main/client/src/model/ko.js
new file mode 100644
index 0000000..5383043
--- /dev/null
+++ b/src/main/client/src/model/ko.js
@@ -0,0 +1,30 @@
+import {
+  updateBoard,
+} from "./base.js"
+import {
+  BLACK,
+  WHITE,
+} from "../util.js"
+
+const NOT_FORBIDDEN = [-1, -1]
+
+export function getForbidden(board, updated, move) {
+  if (!board || !board.length) {
+    return NOT_FORBIDDEN
+  }
+  let {x, y, color, dead} = move
+  if (dead.size() !== 1) {
+    return NOT_FORBIDDEN
+  }
+  let oppositeColor = color ^ (WHITE | BLACK)
+  let dx = dead.x(0)
+  let dy = dead.y(0)
+  let [kill] = updateBoard(updated, {x: dx, y: dy, color: oppositeColor})
+  if (kill.size() !== 1) {
+    return NOT_FORBIDDEN
+  }
+  if (kill.x(0) !== x || kill.y(0) !== y) {
+    return NOT_FORBIDDEN
+  }
+  return [dx, dy]
+}
diff --git a/src/main/client/src/store.js b/src/main/client/src/store.js
index 986cd23..4bf6500 100644
--- a/src/main/client/src/store.js
+++ b/src/main/client/src/store.js
@@ -17,6 +17,9 @@ import {
 import {
   updateBoard,
 } from "./model/base.js"
+import {
+  getForbidden,
+} from "./model/ko.js"
 
 export const useAuthStore = create((set) => ({
   auth: {
@@ -55,9 +58,13 @@ export const useGameStore = create((set, get) => ({
       state.isInCountingGroup = has
     }))
   },
+  currentPlayer: () => {
+    return get().gameState.currentColor === WHITE ?
+        get().white.name :
+        get().black.name
+  },
   gameState: {
     board: [],
-    currentPlayer: undefined,
     currentColor: BLACK,
     counting: false,
     forbidden: [-1, -1],
@@ -80,12 +87,12 @@ export const useGameStore = create((set, get) => ({
         return
       }
       let [dead, updated] = updateBoard(get().baseBoard, move)
-      state.moves.push({...move, dead})
+      let storedMove = {...move, dead}
+      state.moves.push(storedMove)
       state.baseBoard = updated
       state.gameState.board = rehydrate(updated)
       state.gameState.currentColor = get().gameState.currentColor ^ (BLACK | WHITE)
-      state.gameState.currentPlayer = get().gameState.currentPlayer === get().black.name ? get().white.name : get().black.name
-      state.gameState.forbidden = move.forbidden
+      state.gameState.forbidden = getForbidden(get().baseBoard, updated, storedMove)
     }))
   },
   setGameState: (game) => {
@@ -96,7 +103,6 @@ export const useGameStore = create((set, get) => ({
       state.baseBoard = game.board
       state.moves = game.moves
       state.gameState.board = rehydrate(game.board)
-      state.gameState.currentPlayer = game.currentPlayer
       state.gameState.currentColor = game.currentColor
       state.gameState.counting = game.counting
       state.gameState.forbidden = game.forbidden
diff --git a/src/main/java/com/bernd/GameController.java b/src/main/java/com/bernd/GameController.java
index bb861c9..c02af1b 100644
--- a/src/main/java/com/bernd/GameController.java
+++ b/src/main/java/com/bernd/GameController.java
@@ -66,7 +66,7 @@ public void action(Move move, Principal principal) {
     if (updated.counting()) {
       operations.convertAndSend("/topic/move/" + game.id(), CountingMove.create(color, moveNumber, updated.board()));
     } else {
-      operations.convertAndSend("/topic/move/" + game.id(), move.toView(color, moveNumber, updated.forbidden()));
+      operations.convertAndSend("/topic/move/" + game.id(), move.toView(color, moveNumber));
     }
   }
 
diff --git a/src/main/java/com/bernd/game/Direction.java b/src/main/java/com/bernd/game/Direction.java
index 6e57da6..42045e3 100644
--- a/src/main/java/com/bernd/game/Direction.java
+++ b/src/main/java/com/bernd/game/Direction.java
@@ -35,11 +35,11 @@ public static Direction from(int source_x, int source_y, int target_x, int targe
     return NONE;
   }
 
-  public int moveX(int xx) {
-    return xx + inc_x;
+  public int moveX(int x) {
+    return x + inc_x;
   }
 
-  public int moveY(int yy) {
-    return yy + inc_y;
+  public int moveY(int y) {
+    return y + inc_y;
   }
 }
diff --git a/src/main/java/com/bernd/game/MoveList.java b/src/main/java/com/bernd/game/MoveList.java
index 0053408..e886f2b 100644
--- a/src/main/java/com/bernd/game/MoveList.java
+++ b/src/main/java/com/bernd/game/MoveList.java
@@ -77,16 +77,16 @@ public GameMove get(int i) {
     int ptId = i % 2 == 0 ? code & LO : (code >> 16);
     int color = (ptId & WHITE) != 0 ? Board.W : Board.B;
     if ((ptId & GAME_END) != 0) {
-      return new GameMove(i, 0, true, -1, -1, true, true, new int[]{-1, -1});
+      return new GameMove(i, 0, true, -1, -1, true, true);
     }
     boolean counting = (ptId & COUNTING) != 0;
     if ((ptId & PASS) != 0) {
-      return new GameMove(i, color, true, -1, -1, counting, false, new int[]{-1, -1});
+      return new GameMove(i, color, true, -1, -1, counting, false);
     } else {
       int data = ptId & DATA;
       int x = data % dim;
       int y = data / dim;
-      return new GameMove(i, color, false, x, y, counting, false, new int[]{-1, -1});
+      return new GameMove(i, color, false, x, y, counting, false);
     }
   }
 
diff --git a/src/main/java/com/bernd/model/GameMove.java b/src/main/java/com/bernd/model/GameMove.java
index 1350222..273cb7e 100644
--- a/src/main/java/com/bernd/model/GameMove.java
+++ b/src/main/java/com/bernd/model/GameMove.java
@@ -7,6 +7,5 @@ public record GameMove(
     int x,
     int y,
     boolean counting,
-    boolean end,
-    int[] forbidden) {
+    boolean end) {
 }
diff --git a/src/main/java/com/bernd/model/Move.java b/src/main/java/com/bernd/model/Move.java
index d7fcae7..b608e7a 100644
--- a/src/main/java/com/bernd/model/Move.java
+++ b/src/main/java/com/bernd/model/Move.java
@@ -7,7 +7,7 @@ public record Move(
     int x,
     int y) {
 
-  public GameMove toView(int color, int moveNumber, int[] forbidden) {
-    return new GameMove(moveNumber, color, pass, x, y, false, false, forbidden);
+  public GameMove toView(int color, int moveNumber) {
+    return new GameMove(moveNumber, color, pass, x, y, false, false);
   }
 }