diff --git a/.needle-predispatch-sha b/.needle-predispatch-sha
index 7418065..c86ef19 100644
--- a/.needle-predispatch-sha
+++ b/.needle-predispatch-sha
@@ -1 +1 @@
-42e9561e462943ba99c6060c5158944083976f08
+92576dbed4023a672f253baec6230e4e0b218a9f
diff --git a/engine/map_engagement_test.go b/engine/map_engagement_test.go
new file mode 100644
index 0000000..a2c6bf8
--- /dev/null
+++ b/engine/map_engagement_test.go
@@ -0,0 +1,133 @@
+package engine
+
+import (
+	"math/rand"
+	"testing"
+)
+
+// TestMapEngagement_WinProbDependency verifies that CalculateMapEngagement
+// correctly uses win_prob data to count lead changes.
+func TestMapEngagement_WinProbDependency(t *testing.T) {
+	// Create a replay with alternating win probs to simulate lead changes
+	replay := &Replay{
+		Config: Config{Rows: 20, Cols: 20, MaxTurns: 100},
+		Result: &MatchResult{Turns: 50, Scores: []int{5, 4}},
+		WinProb: []WinProbEntry{
+			{0.6, 0.4}, // Player 0 leading
+			{0.4, 0.6}, // Player 1 leading - 1st crossing
+			{0.6, 0.4}, // Player 0 leading - 2nd crossing
+			{0.4, 0.6}, // Player 1 leading - 3rd crossing
+		},
+		Turns: []ReplayTurn{
+			{Turn: 0, Bots: []ReplayBot{{Position: Position{Row: 0, Col: 0}, Alive: true}}},
+			{Turn: 1, Bots: []ReplayBot{{Position: Position{Row: 1, Col: 1}, Alive: true}}},
+		},
+		Map: ReplayMap{
+			Walls: []Position{{Row: 10, Col: 10}},
+		},
+	}
+
+	score := CalculateMapEngagement(replay)
+
+	// Should have 3 win prob crossings (lead changes)
+	if score.WinProbCrossings != 3 {
+		t.Errorf("Expected 3 win_prob crossings, got %.0f", score.WinProbCrossings)
+	}
+
+	// Engagement score should be positive (crossings contribute 3.0 each)
+	if score.Engagement <= 0 {
+		t.Errorf("Expected positive engagement score, got %.2f", score.Engagement)
+	}
+}
+
+// TestMapEngagement_CriticalMomentsDependency verifies that CalculateMapEngagement
+// correctly counts critical moments from the replay.
+func TestMapEngagement_CriticalMomentsDependency(t *testing.T) {
+	replay := &Replay{
+		Config: Config{Rows: 20, Cols: 20, MaxTurns: 100},
+		Result: &MatchResult{Turns: 50, Scores: []int{5, 4}},
+		CriticalMoments: []CriticalMoment{
+			{Turn: 10, Delta: 0.20, Player: 0, Description: "Player 0 scores"},
+			{Turn: 25, Delta: -0.25, Player: 1, Description: "Player 1 fights back"},
+		},
+		Turns: []ReplayTurn{
+			{Turn: 0, Bots: []ReplayBot{{Position: Position{Row: 0, Col: 0}, Alive: true}}},
+		},
+		Map: ReplayMap{
+			Walls: []Position{{Row: 10, Col: 10}},
+		},
+	}
+
+	score := CalculateMapEngagement(replay)
+
+	// Should have 2 critical moments
+	if score.CriticalMoments != 2 {
+		t.Errorf("Expected 2 critical moments, got %d", score.CriticalMoments)
+	}
+
+	// Engagement should include critical moments contribution (2.0 each)
+	expectedContribution := float64(2) * 2.0
+	if score.Engagement < expectedContribution {
+		t.Errorf("Expected engagement >= %.2f from critical moments, got %.2f", expectedContribution, score.Engagement)
+	}
+}
+
+// TestMapEngagement_EmptyReplay handles empty/nil replays gracefully.
+func TestMapEngagement_EmptyReplay(t *testing.T) {
+	score1 := CalculateMapEngagement(nil)
+	score2 := CalculateMapEngagement(&Replay{})
+
+	// Both should return zero scores without panicking
+	if score1.Engagement != 0 || score2.Engagement != 0 {
+		t.Error("Empty replay should return zero engagement")
+	}
+}
+
+// TestWinProb_ComputeAndSet verifies that ComputeWinProbability produces
+// valid results and SetWinProbability correctly stores them.
+func TestWinProb_ComputeAndSet(t *testing.T) {
+	config := DefaultConfig()
+	config.Rows = 10
+	config.Cols = 10
+	config.MaxTurns = 20
+
+	gs := NewGameState(config, rand.New(rand.NewSource(42)))
+	gs.AddPlayer()
+	gs.AddPlayer()
+
+	// Create simple snapshots
+	snapshots := []*GameState{gs.Clone()}
+
+	rng := rand.New(rand.NewSource(123))
+	winProbs, moments := ComputeWinProbability(snapshots, 10, rng)
+
+	// Should have win prob for each snapshot
+	if len(winProbs) != len(snapshots) {
+		t.Errorf("Expected %d win prob entries, got %d", len(snapshots), len(winProbs))
+	}
+
+	// Each entry should have 2 player probabilities
+	for i, entry := range winProbs {
+		if len(entry) != 2 {
+			t.Errorf("WinProb entry %d has %d values, want 2", i, len(entry))
+		}
+		// Values should be in [0, 1]
+		for j, prob := range entry {
+			if prob < 0 || prob > 1 {
+				t.Errorf("WinProb entry %d player %d has invalid prob %.2f", i, j, prob)
+			}
+		}
+	}
+
+	// Verify replay writer can store the data
+	rw := NewReplayWriter("test_match", config)
+	rw.SetWinProbability(winProbs, moments)
+
+	replay := rw.GetReplay()
+	if len(replay.WinProb) != len(winProbs) {
+		t.Errorf("Replay has %d win prob entries, want %d", len(replay.WinProb), len(winProbs))
+	}
+	if len(replay.CriticalMoments) != len(moments) {
+		t.Errorf("Replay has %d critical moments, want %d", len(replay.CriticalMoments), len(moments))
+	}
+}