diff --git a/calculate_average_SamuelYvon.sh b/calculate_average_SamuelYvon.sh
new file mode 100755
index 0000000..da03382
--- /dev/null
+++ b/calculate_average_SamuelYvon.sh
@@ -0,0 +1,19 @@
+#!/bin/sh
+#
+#  Copyright 2023 The original authors
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+
+JAVA_OPTS="--enable-preview"
+java $JAVA_OPTS --class-path target/average-1.0.0-SNAPSHOT.jar dev.morling.onebrc.CalculateAverage_samuelyvon
diff --git a/prepare_SamuelYvon.sh b/prepare_SamuelYvon.sh
new file mode 100755
index 0000000..f83a3ff
--- /dev/null
+++ b/prepare_SamuelYvon.sh
@@ -0,0 +1,19 @@
+#!/bin/bash
+#
+#  Copyright 2023 The original authors
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+
+source "$HOME/.sdkman/bin/sdkman-init.sh"
+sdk use java 21.0.1-graal 1>&2
diff --git a/src/main/java/dev/morling/onebrc/CalculateAverage_samuelyvon.java b/src/main/java/dev/morling/onebrc/CalculateAverage_samuelyvon.java
new file mode 100644
index 0000000..10a2179
--- /dev/null
+++ b/src/main/java/dev/morling/onebrc/CalculateAverage_samuelyvon.java
@@ -0,0 +1,249 @@
+/*
+ *  Copyright 2023 The original authors
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package dev.morling.onebrc;
+
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.nio.MappedByteBuffer;
+import java.nio.channels.FileChannel;
+import java.nio.charset.StandardCharsets;
+import java.util.*;
+import java.util.stream.Collectors;
+
+/**
+ * Samuel Yvon's entry.
+ * <p>
+ * Explanation behind my reasoning:
+ * - I want to make it as fast as possible without it being an unreadable mess; I want to avoid bit fiddling UTF-8
+ * and use the provided facilities
+ * - I use the fact that we know the number of stations to optimize HashMap creation (75% rule)
+ * - I stole branch-less compare from royvanrijn
+ * - I assume valid ASCII encoding for the number part, which allows me to parse it manually
+ * (should hold for valid UTF-8)
+ * - I have not done Java in forever. Especially what the heck it's become. I've looked at the other submissions and
+ * the given sample to get inspiration. I did not even know about this Stream API thing.
+ * </p>
+ *
+ * <p>
+ * Future ideas:
+ * - Probably can Vector-Apirize the number parsing (but it's three to four numbers, is it worth?)
+ * </p>
+ *
+ * <p>
+ * Observations:
+ * - [2024-01-09] The branch-less code from royvarijn does not have a huge impact
+ * </p>
+ *
+ * <p>
+ * Changelogs:
+ * 2024-01-09: Naive multi-threaded, no floats, manual line parsing
+ * </p>
+ */
+public class CalculateAverage_samuelyvon {
+
+    private static final String FILE = "./measurements.txt";
+
+    private static final int MAX_STATIONS = 10000;
+
+    private static final byte SEMICOL = 0x3B;
+
+    private static final byte MINUS = '-';
+
+    private static final byte ZERO = '0';
+
+    private static final byte NEWLINE = '\n';
+
+    // The minimum line length in bytes (over-egg.)
+    private static final int MIN_LINE_LENGTH_BYTES = 200;
+
+    /**
+     * Branchless min (unprecise for large numbers, but good enough)
+     *
+     * @author royvanrijn
+     */
+    private static int branchlessMax(final int a, final int b) {
+        final int diff = a - b;
+        final int dsgn = diff >> 31;
+        return a - (diff & dsgn);
+    }
+
+    /**
+     * Branchless min (unprecise for large numbers, but good enough)
+     *
+     * @author royvanrijn
+     */
+    private static int branchlessMin(final int a, final int b) {
+        final int diff = a - b;
+        final int dsgn = diff >> 31;
+        return b + (diff & dsgn);
+    }
+
+    private static class StationMeasureAgg {
+        private int min;
+        private int max;
+        private long sum;
+        private long count;
+
+        private final String city;
+
+        public StationMeasureAgg(String city) {
+            // Actual numbers are between -99.9 and 99.9, but we *10 to avoid float
+            this.city = city;
+            min = 1000;
+            max = -1000;
+            sum = 0;
+            count = 0;
+        }
+
+        public String city() {
+            return this.city;
+        }
+
+        public StationMeasureAgg mergeWith(StationMeasureAgg other) {
+            min = branchlessMin(min, other.min);
+            max = branchlessMax(max, other.max);
+
+            sum += other.sum;
+            count += other.count;
+
+            return this;
+        }
+
+        public void accumulate(int number) {
+            min = branchlessMin(min, number);
+            max = branchlessMax(max, number);
+
+            sum += number;
+            count++;
+        }
+
+        @Override
+        public String toString() {
+            double min = Math.round((double) this.min) / 10.0;
+            double max = Math.round((double) this.max) / 10.0;
+            double mean = Math.round((((double) this.sum / this.count))) / 10.0;
+            return min + "/" + mean + "/" + max;
+        }
+    }
+
+    private static HashMap<String, StationMeasureAgg> parseChunk(MappedByteBuffer chunk) {
+        HashMap<String, StationMeasureAgg> m = HashMap.newHashMap(MAX_STATIONS);
+
+        int i = 0;
+        while (i < chunk.limit()) {
+            int j = i;
+            for (; j < chunk.limit(); ++j) {
+                // TODO: Could compute a hash here, store a byte array, and decode UTF-8 at the
+                // latest moment.
+                if (chunk.get(j) == SEMICOL) {
+                    break;
+                }
+            }
+
+            byte[] backingNameArray = new byte[j - i];
+            chunk.get(i, backingNameArray);
+            String name = new String(backingNameArray, StandardCharsets.UTF_8);
+
+            // Skip the `;`
+            j++;
+
+            // Parse the int ourselves, avoids a 'String::replace' to remove the
+            // digit.
+            int temp = 0;
+            boolean neg = chunk.get(j) == MINUS;
+            for (j = j + (neg ? 1 : 0); j < chunk.limit(); ++j) {
+                temp *= 10;
+                byte c = chunk.get(j);
+                if (c != '.') {
+                    temp += (char) (c - ZERO);
+                }
+                else {
+                    j++;
+                    break;
+                }
+            }
+
+            // The decimal point
+            temp += (char) (chunk.get(j) - ZERO);
+
+            i = j + 1;
+
+            while (chunk.get(i++) != '\n')
+                ;
+
+            if (neg)
+                temp = -temp;
+
+            m.computeIfAbsent(name, StationMeasureAgg::new).accumulate(temp);
+        }
+
+        return m;
+    }
+
+    private static int approximateChunks() {
+        // https://stackoverflow.com/a/4759606
+        // I don't remember Java :D
+        return Runtime.getRuntime().availableProcessors();
+    }
+
+    private static List<MappedByteBuffer> getFileChunks() throws IOException {
+        int approxChunkCount = approximateChunks();
+
+        List<MappedByteBuffer> fileChunks = new ArrayList<>(approxChunkCount * 2);
+
+        // Compute chunks offsets and lengths
+        try (RandomAccessFile file = new RandomAccessFile(FILE, "r")) {
+            long totalOffset = 0;
+            long fLength = file.length();
+            long approximateLength = Long.max(fLength / approxChunkCount, MIN_LINE_LENGTH_BYTES);
+
+            while (totalOffset < fLength) {
+                long offset = totalOffset;
+                int length = (int) approximateLength;
+
+                boolean eof = offset + length >= fLength;
+                if (eof) {
+                    length = (int) (fLength - offset);
+                }
+
+                MappedByteBuffer out = file.getChannel().map(FileChannel.MapMode.READ_ONLY, totalOffset, length);
+
+                while (out.get(length - 1) != NEWLINE) {
+                    length--;
+                }
+
+                out.position(0);
+                out.limit(length);
+
+                fileChunks.add(out);
+
+                totalOffset += length;
+            }
+        }
+
+        return fileChunks;
+    }
+
+    public static void main(String[] args) throws IOException {
+        var fileChunks = getFileChunks();
+
+        // Map per core, giving the non-overlapping memory slices
+        final Map<String, StationMeasureAgg> sortedMeasures = fileChunks.parallelStream().map(CalculateAverage_samuelyvon::parseChunk)
+                .flatMap(x -> x.values().stream()).collect(Collectors.toMap(StationMeasureAgg::city, x -> x, StationMeasureAgg::mergeWith, TreeMap::new));
+
+        System.out.println(sortedMeasures);
+    }
+}