diff --git a/13_Bounce/csharp/Bounce.cs b/13_Bounce/csharp/Bounce.cs
new file mode 100644
index 00000000..c250e7df
--- /dev/null
+++ b/13_Bounce/csharp/Bounce.cs
@@ -0,0 +1,38 @@
+namespace Bounce;
+
+/// <summary>
+/// Represents the bounce of the ball, calculating duration, height and position in time.
+/// </summary>
+/// <remarks>
+/// All calculations are derived from the equation for projectile motion: s = vt + 0.5at^2
+/// </remarks>
+internal class Bounce
+{
+    private const float _acceleration = -32; // feet/s^2
+
+    private readonly float _velocity;
+
+    internal Bounce(float velocity)
+    {
+        _velocity = velocity;
+    }
+
+    public float Duration => -2 * _velocity / _acceleration;
+
+    public float MaxHeight =>
+        (float)Math.Round(-_velocity * _velocity / 2 / _acceleration, MidpointRounding.AwayFromZero);
+
+    public float Plot(Graph graph, float startTime)
+    {
+        var time = 0f;
+        for (; time <= Duration; time += graph.TimeIncrement)
+        {
+            var height = _velocity * time + _acceleration * time * time / 2;
+            graph.Plot(startTime + time, height);
+        }
+
+        return startTime + time;
+    }
+
+    public Bounce Next(float elasticity) => new Bounce(_velocity * elasticity);
+}
diff --git a/13_Bounce/csharp/Game.cs b/13_Bounce/csharp/Game.cs
index 1bf8236d..8d2baf8b 100644
--- a/13_Bounce/csharp/Game.cs
+++ b/13_Bounce/csharp/Game.cs
@@ -1,13 +1,9 @@
-using System.Text;
 using static Bounce.Resources.Resource;
 
 namespace Bounce;
 
 internal class Game
 {
-    private const int _chartWidth = 70;
-    private const float _acceleration = -32; // feet/s^2
-
     private readonly IReadWrite _io;
 
     public Game(IReadWrite io)
@@ -20,130 +16,20 @@ internal class Game
         _io.Write(Streams.Title);
         _io.Write(Streams.Instructions);
 
-        var increment = _io.ReadParameter("Time increment (sec)");
+        var timeIncrement = _io.ReadParameter("Time increment (sec)");
         var velocity = _io.ReadParameter("Velocity (fps)");
         var elasticity = _io.ReadParameter("Coefficient");
 
-        var timeToFirstBounce = -2 * velocity / _acceleration;
-        var bounceCount = (int)(Graph.Row.Width * increment / timeToFirstBounce);
+        var bounce = new Bounce(velocity);
+        var bounceCount = (int)(Graph.Row.Width * timeIncrement / bounce.Duration);
+        var graph = new Graph(bounce.MaxHeight, timeIncrement);
 
-        var maxHeight = (float)Math.Round(-velocity * velocity / 2 / _acceleration, MidpointRounding.AwayFromZero);
-
-        var graph = new Graph(maxHeight, increment);
-
-        var totalTime = 0f;
-        for (var bounce = 0; bounce < bounceCount; bounce++, velocity *= elasticity)
+        var time = 0f;
+        for (var i = 0; i < bounceCount; i++, bounce = bounce.Next(elasticity))
         {
-            var bounceDuration = -2 * velocity / _acceleration;
-            for (var time = 0f; time <= bounceDuration; totalTime += increment, time += increment)
-            {
-                var height = velocity * time + _acceleration * time * time / 2;
-                graph.Plot(totalTime, height);
-            }
+            time = bounce.Plot(graph, time);
         }
 
         _io.WriteLine(graph);
     }
 }
-
-internal class Graph
-{
-    private readonly Dictionary<int, Row> _rows;
-    private readonly float _increment;
-    private float _maxTimePlotted;
-
-    public Graph(float maxHeight, float increment)
-    {
-        // 1 row == 1/2 foot + 1 row for zero
-        var rowCount = 2 * (int)Math.Round(maxHeight, MidpointRounding.AwayFromZero) + 1;
-        _rows = Enumerable.Range(0, rowCount)
-            .ToDictionary(x => x, x => new Row(x % 2 == 0 ? $" {x / 2} " : ""));
-        _increment = increment;
-    }
-
-    public void Plot(float time, float height)
-    {
-        var rowIndex = (int)Math.Round(height * 2, MidpointRounding.AwayFromZero);
-        var colIndex = (int)(time / _increment) + 1;
-        if (_rows.TryGetValue(rowIndex, out var row))
-        {
-            row[colIndex] = '0';
-        }
-        _maxTimePlotted = Math.Max(time, _maxTimePlotted);
-    }
-
-    public override string ToString()
-    {
-        var sb = new StringBuilder();
-        foreach (var (_, row) in _rows.OrderByDescending(x => x.Key))
-        {
-            sb.Append(row).AppendLine();
-        }
-        var maxTimeMark = (int)Math.Ceiling(_maxTimePlotted);
-        sb.Append(' ').Append('.', (int)(maxTimeMark/_increment) + 1).AppendLine();
-
-        var timeLabels = new Labels();
-        for (var i = 1; i <= maxTimeMark; i++)
-        {
-            timeLabels.Add((int)(i / _increment), $" {i} ");
-        }
-        sb.Append(timeLabels).AppendLine();
-        sb.Append(' ', (int)((int)(_maxTimePlotted + 1)/_increment/2 - 2)).AppendLine("Seconds");
-
-        return sb.ToString();
-    }
-
-    internal class Row
-    {
-        public const int Width = 70;
-
-        private readonly char[] _chars = new char[Width + 2];
-        private int nextColumn = 0;
-
-        public Row(string label)
-        {
-            Array.Fill(_chars, ' ');
-            Array.Copy(label.ToCharArray(), _chars, label.Length);
-            nextColumn = label.Length;
-        }
-
-        public char this[int column]
-        {
-            set
-            {
-                if (column >= _chars.Length) { return; }
-                if (column < nextColumn) { column = nextColumn; }
-                _chars[column] = value;
-                nextColumn = column + 1;
-            }
-        }
-
-        public override string ToString() => new string(_chars);
-    }
-
-    internal class Labels : Row
-    {
-        public Labels()
-            : base(" 0")
-        {
-        }
-
-        public void Add(int column, string label)
-        {
-            for (var i = 0; i < label.Length; i++)
-            {
-                this[column + i] = label[i];
-            }
-        }
-    }
-}
-
-internal static class IReadWriteExtensions
-{
-    internal static float ReadParameter(this IReadWrite io, string parameter)
-    {
-        var value = io.ReadNumber(parameter);
-        io.WriteLine();
-        return value;
-    }
-}
\ No newline at end of file
diff --git a/13_Bounce/csharp/Graph.cs b/13_Bounce/csharp/Graph.cs
new file mode 100644
index 00000000..608b5bda
--- /dev/null
+++ b/13_Bounce/csharp/Graph.cs
@@ -0,0 +1,116 @@
+using System.Text;
+
+namespace Bounce;
+
+/// <summary>
+/// Provides support for plotting a graph of height vs time, and rendering it to a string.
+/// </summary>
+internal class Graph
+{
+    private readonly Dictionary<int, Row> _rows;
+
+    public Graph(float maxHeight, float timeIncrement)
+    {
+        // 1 row == 1/2 foot + 1 row for zero
+        var rowCount = 2 * (int)Math.Round(maxHeight, MidpointRounding.AwayFromZero) + 1;
+        _rows = Enumerable.Range(0, rowCount)
+            .ToDictionary(x => x, x => new Row(x % 2 == 0 ? $" {x / 2} " : ""));
+        TimeIncrement = timeIncrement;
+    }
+
+    public float TimeIncrement { get; }
+    public float MaxTimePlotted { get; private set; }
+
+    public void Plot(float time, float height)
+    {
+        var rowIndex = (int)Math.Round(height * 2, MidpointRounding.AwayFromZero);
+        var colIndex = (int)(time / TimeIncrement) + 1;
+        if (_rows.TryGetValue(rowIndex, out var row))
+        {
+            row[colIndex] = '0';
+        }
+        MaxTimePlotted = Math.Max(time, MaxTimePlotted);
+    }
+
+    public override string ToString()
+    {
+        var sb = new StringBuilder().AppendLine("Feet").AppendLine();
+        foreach (var (_, row) in _rows.OrderByDescending(x => x.Key))
+        {
+            sb.Append(row).AppendLine();
+        }
+        sb.Append(new Axis(MaxTimePlotted, TimeIncrement));
+
+        return sb.ToString();
+    }
+
+    internal class Row
+    {
+        public const int Width = 70;
+
+        private readonly char[] _chars = new char[Width + 2];
+        private int nextColumn = 0;
+
+        public Row(string label)
+        {
+            Array.Fill(_chars, ' ');
+            Array.Copy(label.ToCharArray(), _chars, label.Length);
+            nextColumn = label.Length;
+        }
+
+        public char this[int column]
+        {
+            set
+            {
+                if (column >= _chars.Length) { return; }
+                if (column < nextColumn) { column = nextColumn; }
+                _chars[column] = value;
+                nextColumn = column + 1;
+            }
+        }
+
+        public override string ToString() => new string(_chars);
+    }
+
+    internal class Axis
+    {
+        private readonly int _maxTimeMark;
+        private readonly float _timeIncrement;
+        private readonly Labels _labels;
+
+        internal Axis(float maxTimePlotted, float timeIncrement)
+        {
+            _maxTimeMark = (int)Math.Ceiling(maxTimePlotted);
+            _timeIncrement = timeIncrement;
+
+            _labels = new Labels();
+            for (var i = 1; i <= _maxTimeMark; i++)
+            {
+                _labels.Add((int)(i / _timeIncrement), $" {i} ");
+            }
+        }
+
+        public override string ToString()
+            => new StringBuilder()
+                .Append(' ').Append('.', (int)(_maxTimeMark / _timeIncrement) + 1).AppendLine()
+                .Append(_labels).AppendLine()
+                .Append(' ', (int)(_maxTimeMark / _timeIncrement / 2 - 2)).AppendLine("Seconds")
+                .ToString();
+    }
+
+    internal class Labels : Row
+    {
+        public Labels()
+            : base(" 0")
+        {
+        }
+
+        public void Add(int column, string label)
+        {
+            for (var i = 0; i < label.Length; i++)
+            {
+                this[column + i] = label[i];
+            }
+        }
+    }
+}
diff --git a/13_Bounce/csharp/IReadWriteExtensions.cs b/13_Bounce/csharp/IReadWriteExtensions.cs
new file mode 100644
index 00000000..bafeee42
--- /dev/null
+++ b/13_Bounce/csharp/IReadWriteExtensions.cs
@@ -0,0 +1,11 @@
+namespace Bounce;
+
+internal static class IReadWriteExtensions
+{
+    internal static float ReadParameter(this IReadWrite io, string parameter)
+    {
+        var value = io.ReadNumber(parameter);
+        io.WriteLine();
+        return value;
+    }
+}
\ No newline at end of file