diff --git a/src/lib/speedometer/chart.ts b/src/lib/speedometer/chart.ts
index 71b1660..cfb88ff 100644
--- a/src/lib/speedometer/chart.ts
+++ b/src/lib/speedometer/chart.ts
@@ -41,6 +41,8 @@ export interface ChartInputs {
 	 * score; Android also charts mWh, so it supplies its own.
 	 */
 	yLabel?: string;
+	/** Anchor the y axis at zero rather than fitting it to the data. */
+	beginAtZero?: boolean;
 }
 
 function stableJitter(seed: number): number {
@@ -261,7 +263,7 @@ export function buildChartOptions(
 				title: { display: true, text: 'Date' }
 			},
 			y: {
-				beginAtZero: false,
+				beginAtZero: inputs.beginAtZero ?? false,
 				title: { display: true, text: yLabel }
 			}
 		}
diff --git a/src/lib/speedometer/config.ts b/src/lib/speedometer/config.ts
index 01e9282..658133f 100644
--- a/src/lib/speedometer/config.ts
+++ b/src/lib/speedometer/config.ts
@@ -81,13 +81,6 @@ export const PLATFORMS: readonly PlatformConfig[] = [
 		safariPlatform: 'macosx2700-aarch64-shippable',
 		group: 'desktop'
 	},
-	{
-		key: 'osx',
-		label: 'Mac (Intel)',
-		platforms: ['macosx1470-64-nightlyasrelease', 'macosx1470-64-shippable'],
-		supportsSafari: false,
-		group: 'desktop'
-	},
 	{
 		key: 'android-s24',
 		label: 'Android (S24)',
diff --git a/src/routes/navbench/+page.svelte b/src/routes/navbench/+page.svelte
index 639b51b..9b217bf 100644
--- a/src/routes/navbench/+page.svelte
+++ b/src/routes/navbench/+page.svelte
@@ -132,7 +132,8 @@
 		markers: [],
 		annotations: annotationsWithinDays(annotationsFor(selectedTest), range),
 		reference: selection,
-		yLabel: 'Score (higher is better)'
+		yLabel: 'Score (higher is better)',
+		beginAtZero: true
 	});
 
 	const chartConfig = $derived(buildChartData(chartInputs));
diff --git a/src/routes/navbench/SubtestChart.svelte b/src/routes/navbench/SubtestChart.svelte
index d58a48c..90a6fff 100644
--- a/src/routes/navbench/SubtestChart.svelte
+++ b/src/routes/navbench/SubtestChart.svelte
@@ -35,7 +35,8 @@
 		markers: [],
 		annotations: annotationsWithinDays(annotationsFor(test), days),
 		reference: null,
-		yLabel: 'Score (higher is better)'
+		yLabel: 'Score (higher is better)',
+		beginAtZero: true
 	});
 
 	const chartData = $derived(buildChartData(inputs));