diff --git a/src/components/ChatCards.js b/src/components/ChatCards.js
index 8bdc211..a68ae6b 100644
--- a/src/components/ChatCards.js
+++ b/src/components/ChatCards.js
@@ -5,7 +5,7 @@ import Typography from "@material-ui/core/Typography";
 import { makeStyles } from "@material-ui/core/styles";
 
 import { cardsFromEvent, checkSetUltra, conjugateCard, modes } from "../game";
-import { formatTime } from "../util";
+import { formatCount, formatTime } from "../util";
 import SetCard from "./SetCard";
 import User from "./User";
 
@@ -35,40 +35,52 @@ const useStyles = makeStyles((theme) => ({
 function ChatCards({ item, gameMode, startedAt }) {
   const classes = useStyles();
   const setType = modes[gameMode].setType;
-  let cards = cardsFromEvent(item);
-  if (setType === "UltraSet") {
-    // Arrange cards in pairs and add the 5th card
-    cards = checkSetUltra(...cards) || cards.slice();
-    cards.splice(2, 0, conjugateCard(cards[0], cards[1]), null);
+  let cards;
+  if (!item.kind) {
+    cards = cardsFromEvent(item);
+    if (setType === "UltraSet") {
+      // Arrange cards in pairs and add the 5th card
+      cards = checkSetUltra(...cards) || cards.slice();
+      cards.splice(2, 0, conjugateCard(cards[0], cards[1]), null);
+    }
   }
 
   return (
     <Tooltip arrow placement="left" title={formatTime(item.time - startedAt)}>
       <div className={classes.logEntry}>
         <div className={classes.logEntryText}>
-          <Typography variant="subtitle2" style={{ marginRight: "0.2em" }}>
-            {setType} found by
+          <Typography variant="subtitle2">
+            {item.kind === "board_done"
+              ? `Board clear: ${formatCount(item.count, setType)}`
+              : `${setType} found by`}
           </Typography>
-          <User
-            component={Typography}
-            noWrap={true}
-            variant="subtitle2"
-            id={item.user}
-          />
-        </div>
-        <div className={classes.setCards}>
-          {setType === "Set" &&
-            cards.map((card) => <SetCard key={card} size="sm" value={card} />)}
-          {(setType === "UltraSet" || setType === "GhostSet") &&
-            Array.from(Array(3), (_, i) => (
-              <div key={i} className={classes.cardsColumn}>
-                <SetCard size="sm" value={cards[i * 2]} />
-                {cards[i * 2 + 1] && (
-                  <SetCard size="sm" value={cards[i * 2 + 1]} />
-                )}
-              </div>
-            ))}
+          {item.user && (
+            <User
+              component={Typography}
+              noWrap={true}
+              variant="subtitle2"
+              id={item.user}
+              style={{ marginLeft: "0.2em" }}
+            />
+          )}
         </div>
+        {cards && (
+          <div className={classes.setCards}>
+            {setType === "Set" &&
+              cards.map((card) => (
+                <SetCard key={card} size="sm" value={card} />
+              ))}
+            {(setType === "UltraSet" || setType === "GhostSet") &&
+              Array.from(Array(3), (_, i) => (
+                <div key={i} className={classes.cardsColumn}>
+                  <SetCard size="sm" value={cards[i * 2]} />
+                  {cards[i * 2 + 1] && (
+                    <SetCard size="sm" value={cards[i * 2 + 1]} />
+                  )}
+                </div>
+              ))}
+          </div>
+        )}
       </div>
     </Tooltip>
   );
diff --git a/src/components/Game.js b/src/components/Game.js
index cab552b..4ecc789 100644
--- a/src/components/Game.js
+++ b/src/components/Game.js
@@ -1,4 +1,4 @@
-import { useContext, useMemo } from "react";
+import { useContext, useEffect, useMemo, useState } from "react";
 
 import Divider from "@material-ui/core/Divider";
 import Paper from "@material-ui/core/Paper";
@@ -31,6 +31,7 @@ function Game({
   selected,
   answer,
   lastSet,
+  lastKeptSet,
   faceDown,
   showShortcuts,
   remaining = -1,
@@ -40,6 +41,16 @@ function Game({
   const isHorizontal = cardOrientation === "horizontal";
   const isLandscape = layoutOrientation === "landscape";
   const [gameDimensions, gameEl] = useDimensions();
+  const [highlightCards, setHighlightCards] = useState(null);
+
+  const lastKeptCards = lastKeptSet?.join("|");
+  useEffect(() => {
+    setHighlightCards(lastKeptCards?.split("|"));
+    if (lastKeptCards) {
+      const timer = setTimeout(() => setHighlightCards(null), 500);
+      return () => clearTimeout(timer);
+    }
+  }, [lastKeptCards]);
 
   [board, lastSet] = useMemo(
     () => addLastSet(board, lastSet),
@@ -249,6 +260,7 @@ function Game({
                   width={cardWidth}
                   hinted={answer?.includes(card)}
                   active={selected?.includes(card)}
+                  highlight={highlightCards?.includes(card)}
                   faceDown={
                     faceDown === "all" ||
                     (faceDown &&
diff --git a/src/components/ResponsiveSetCard.js b/src/components/ResponsiveSetCard.js
index e8f5207..6bbe462 100644
--- a/src/components/ResponsiveSetCard.js
+++ b/src/components/ResponsiveSetCard.js
@@ -18,7 +18,8 @@ const useStyles = makeStyles((theme) => ({
     justifyContent: "center",
     flexShrink: 0,
     backgroundColor: theme.setCard.background,
-    transition: "box-shadow 0.15s",
+    transition:
+      "box-shadow 0.15s, width 0.5s, height 0.5s, background-color 0.3s",
   },
   clickable: {
     cursor: "pointer",
@@ -31,6 +32,9 @@ const useStyles = makeStyles((theme) => ({
   active: {
     boxShadow: "0px 0px 5px 3px #4b9e9e !important",
   },
+  highlight: {
+    backgroundColor: theme.setCard.highlight,
+  },
   hintedOverlay: {
     position: "absolute",
     inset: 0,
@@ -71,7 +75,7 @@ function ResponsiveSetCard(props) {
   const theme = useTheme();
 
   // Black magic below to scale cards given any width
-  const { width, value, onClick, hinted, active, faceDown } = props;
+  const { width, value, onClick, hinted, active, highlight, faceDown } = props;
   const height = Math.round(width / 1.6);
   const margin = Math.round(width * 0.035);
   const contentWidth = width - 2 * margin;
@@ -109,6 +113,7 @@ function ResponsiveSetCard(props) {
       className={clsx(classes.card, {
         [classes.clickable]: onClick,
         [classes.active]: active,
+        [classes.highlight]: highlight,
       })}
       style={{
         ...extraStyle,
@@ -118,7 +123,6 @@ function ResponsiveSetCard(props) {
         margin: margin,
         borderRadius: margin,
         border: faceDown ? undefined : BORDERS[border],
-        transition: "width 0.5s, height 0.5s",
       }}
       onClick={onClick}
     >
diff --git a/src/game.js b/src/game.js
index 3d80019..2a571b8 100644
--- a/src/game.js
+++ b/src/game.js
@@ -1,3 +1,5 @@
+import { formatCount } from "./util";
+
 export const BASE_RATING = 1200;
 export const SCALING_FACTOR = 800;
 
@@ -108,11 +110,10 @@ export function addCard(deck, card, gameMode, findState) {
   if (doChain) {
     const fromLast = cards.reduce((s, c) => s + lastSet.includes(c), 0);
     if (fromLast !== chain) {
-      const noun = chain > 1 ? "cards" : "card";
       return {
         kind: "error",
         cards,
-        error: `${chain} ${noun} must be from the previous ${setType}`,
+        error: `${formatCount(chain, "card")} must be from the previous ${setType}`,
       };
     }
   }
@@ -295,7 +296,7 @@ function processValidEvent(internalGameState, event, cards) {
   history.push(event);
 }
 
-function updateBoard(internalGameState, cards) {
+function updateBoard(internalGameState, event, cards) {
   const { current, gameMode, puzzle, boardSize, minBoardSize, findState } =
     internalGameState;
   // in puzzle modes only advance after all sets were found
@@ -304,6 +305,17 @@ function updateBoard(internalGameState, cards) {
     if (findSet(board, gameMode, findState)) return;
     findState.foundSets.clear();
     cards = board;
+    // add a synthetic event to show in chat that the board changed
+    const { history } = internalGameState;
+    let i;
+    for (i = history.length - 2; i >= 0; i--) {
+      if (history[i].kind === "board_done") break;
+    }
+    history.push({
+      time: event.time,
+      kind: "board_done",
+      count: history.length - 1 - i,
+    });
   }
   // remove cards, preserving positions when possible
   removeCards(internalGameState, cards);
@@ -333,7 +345,7 @@ function processEvent(internalGameState, event) {
     findState.lastSet = allCards;
   }
   processValidEvent(internalGameState, event, cards);
-  updateBoard(internalGameState, cards);
+  updateBoard(internalGameState, event, cards);
 }
 
 export function computeState(gameData, gameMode) {
diff --git a/src/pages/GamePage.js b/src/pages/GamePage.js
index 1ca3cef..55a0a21 100644
--- a/src/pages/GamePage.js
+++ b/src/pages/GamePage.js
@@ -24,10 +24,12 @@ import { SettingsContext, UserContext } from "../context";
 import firebase, { createGame, finishGame } from "../firebase";
 import {
   addCard,
+  cardsFromEvent,
   computeState,
   eventFromCards,
   findSet,
   generateDeck,
+  modes,
   removeCard,
 } from "../game";
 import useFirebaseRef from "../hooks/useFirebaseRef";
@@ -142,15 +144,29 @@ function GamePage({ match }) {
     );
   }, [gameMode, gameData?.deck, gameData?.seed]);
 
-  const { current, scores, lastEvents, history, board, answer, findState } =
-    useMemo(() => {
-      if (!gameData) return {};
-      const state = computeState({ ...gameData, deck }, gameMode);
-      const { current, boardSize, findState } = state;
-      const board = current.slice(0, boardSize);
-      const answer = findSet(board, gameMode, findState);
-      return { ...state, board, answer };
-    }, [gameMode, gameData, deck]);
+  const {
+    current,
+    scores,
+    lastEvents,
+    history,
+    board,
+    answer,
+    findState,
+    lastKeptSet,
+  } = useMemo(() => {
+    if (!gameData) return {};
+    const state = computeState({ ...gameData, deck }, gameMode);
+    const { current, boardSize, findState, history } = state;
+    const board = current.slice(0, boardSize);
+    const answer = findSet(board, gameMode, findState);
+    const lastKeptSet =
+      modes[gameMode].puzzle &&
+      history.length &&
+      !history[history.length - 1].kind
+        ? cardsFromEvent(history[history.length - 1])
+        : null;
+    return { ...state, board, answer, lastKeptSet };
+  }, [gameMode, gameData, deck]);
 
   if (redirect) return <Redirect push to={redirect} />;
 
@@ -414,6 +430,7 @@ function GamePage({ match }) {
               onClick={handleClick}
               onClear={handleClear}
               lastSet={findState.lastSet}
+              lastKeptSet={lastKeptSet}
               answer={hint}
               remaining={current.length - board.length}
               faceDown={paused ? "all" : gameMode === "memory" ? "deal" : ""}
diff --git a/src/themes.js b/src/themes.js
index 10a1484..9b8ae22 100644
--- a/src/themes.js
+++ b/src/themes.js
@@ -1,6 +1,4 @@
-import { grey } from "@material-ui/core/colors";
-import { indigo } from "@material-ui/core/colors";
-import { red } from "@material-ui/core/colors";
+import { grey, indigo, red } from "@material-ui/core/colors";
 import { createTheme } from "@material-ui/core/styles";
 
 export const darkTheme = createTheme({
@@ -48,6 +46,7 @@ export const darkTheme = createTheme({
     red: "#ffb047",
     background: "#262626",
     hinted: "rgba(41, 182, 246, 0.25)",
+    highlight: "rgba(75, 158, 158, 0.3)",
     backColors: [
       grey[900],
       grey[800],
@@ -96,6 +95,7 @@ export const lightTheme = createTheme({
     red: "#ff0101",
     background: "#fff",
     hinted: "rgba(3, 169, 244, 0.2)",
+    highlight: "rgba(255, 234, 0, 0.3)",
     backColors: [
       indigo[600],
       indigo[300],
diff --git a/src/util.js b/src/util.js
index 6b2ef5a..2358a6e 100644
--- a/src/util.js
+++ b/src/util.js
@@ -112,6 +112,11 @@ export function formatTime(t, hideSubsecond) {
   return (hours ? `${hours}:` : "") + moment.utc(rest).format(format);
 }
 
+export function formatCount(count, singular, plural = null) {
+  const noun = count === 1 ? singular : (plural ?? singular + "s");
+  return `${count} ${noun}`;
+}
+
 export function censorText(text) {
   return censor.applyTo(text, badWords.getAllMatches(text));
 }