diff --git a/BizHawk.MultiClient/tools/Watch/NewRamSearch.cs b/BizHawk.MultiClient/tools/Watch/NewRamSearch.cs
index 3b341e8a95..23ad73cb7d 100644
--- a/BizHawk.MultiClient/tools/Watch/NewRamSearch.cs
+++ b/BizHawk.MultiClient/tools/Watch/NewRamSearch.cs
@@ -69,10 +69,7 @@ namespace BizHawk.MultiClient
 					text = Searches[index].ValueString;
 					break;
 				case PREV:
-					if (Searches[index] is IWatchDetails)
-					{
-						text = (Searches[index] as IWatchDetails).PreviousStr;
-					}
+					text = Searches[index].PreviousStr;
 					break;
 				case CHANGES:
 					if (Searches[index] is IWatchDetails)
diff --git a/BizHawk.MultiClient/tools/Watch/RamWatch.cs b/BizHawk.MultiClient/tools/Watch/RamWatch.cs
index e2a0a7582e..4e23790d25 100644
--- a/BizHawk.MultiClient/tools/Watch/RamWatch.cs
+++ b/BizHawk.MultiClient/tools/Watch/RamWatch.cs
@@ -288,10 +288,7 @@ namespace BizHawk.MultiClient
 					text = Watches[index].ValueString;
 					break;
 				case PREV:
-					if (Watches[index] is IWatchDetails)
-					{
-						text = (Watches[index] as IWatchDetails).PreviousStr;
-					}
+					text = Watches[index].PreviousStr;
 					break;
 				case CHANGES:
 					if (Watches[index] is IWatchDetails)
@@ -711,7 +708,7 @@ namespace BizHawk.MultiClient
 				case VALUE:
 					return Watches[index].ValueString;
 				case PREV:
-					return (Watches[index] as IWatchDetails).PreviousStr;
+					return Watches[index].PreviousStr;
 				case CHANGES:
 					return (Watches[index] as IWatchDetails).ChangeCount.ToString();
 				case DIFF:
diff --git a/BizHawk.MultiClient/tools/Watch/Watch.cs b/BizHawk.MultiClient/tools/Watch/Watch.cs
index c69be35794..53af5a94d8 100644
--- a/BizHawk.MultiClient/tools/Watch/Watch.cs
+++ b/BizHawk.MultiClient/tools/Watch/Watch.cs
@@ -44,6 +44,10 @@ namespace BizHawk.MultiClient
 		public abstract int? Value { get; }
 		public abstract string ValueString { get; }
 		public abstract WatchSize Size { get; }
+		
+		public abstract int? Previous { get; }
+		public abstract string PreviousStr { get; }
+		public abstract void ResetPrevious();
 
 		public abstract bool Poke(string value);
 
@@ -298,13 +302,8 @@ namespace BizHawk.MultiClient
 	{
 		int ChangeCount { get; }
 		void ClearChangeCount();
-
-		int? Previous { get; }
-		string PreviousStr { get; }
-		void ResetPrevious();
 		string Diff { get; }
 		string Notes { get; set; }
-
 		void Update();
 	}
 
@@ -325,6 +324,11 @@ namespace BizHawk.MultiClient
 			get { return null; }
 		}
 
+		public override int? Previous
+		{
+			get { return null; }
+		}
+
 		public override string AddressString
 		{
 			get { return String.Empty; }
@@ -335,6 +339,11 @@ namespace BizHawk.MultiClient
 			get { return String.Empty; }
 		}
 
+		public override string PreviousStr
+		{
+			get { return String.Empty; }
+		}
+
 		public override string ToString()
 		{
 			return "----";
@@ -364,14 +373,22 @@ namespace BizHawk.MultiClient
 		{
 			return false;
 		}
+
+		public override void ResetPrevious()
+		{
+			return;
+		}
 	}
 
 	public class ByteWatch : Watch
 	{
+		protected byte _previous;
+
 		public ByteWatch(MemoryDomain domain, int address)
 		{
 			_address = address;
 			_domain = domain;
+			_previous = GetByte();
 		}
 
 		public override int? Address
@@ -389,6 +406,21 @@ namespace BizHawk.MultiClient
 			get { return FormatValue(GetByte()); }
 		}
 
+		public override int? Previous
+		{
+			get { return _previous; }
+		}
+
+		public override string PreviousStr
+		{
+			get { return FormatValue(_previous); }
+		}
+
+		public override void ResetPrevious()
+		{
+			_previous = GetByte();
+		}
+
 		public override string ToString()
 		{
 			return AddressString + ": " + ValueString;
@@ -490,16 +522,15 @@ namespace BizHawk.MultiClient
 		}
 	}
 
-	public class DetailedByteWatch : ByteWatch, IWatchDetails
+	public sealed class DetailedByteWatch : ByteWatch, IWatchDetails
 	{
 		private byte _value;
-		private byte _previous;
 
 		public DetailedByteWatch(MemoryDomain domain, int address)
 			: base(domain, address)
 		{
 			Notes = String.Empty;
-			_previous = _value = GetByte();
+			_value = GetByte();
 		}
 
 		public override string ToString()
@@ -510,10 +541,6 @@ namespace BizHawk.MultiClient
 		public int ChangeCount { get; private set; }
 		public void ClearChangeCount() { ChangeCount = 0; }
 
-		public int? Previous { get { return _previous; } }
-		public string PreviousStr { get { return FormatValue(_previous); } }
-		public void ResetPrevious() { _previous = _value; }
-
 		public string Diff
 		{
 			get
@@ -565,10 +592,13 @@ namespace BizHawk.MultiClient
 
 	public class WordWatch : Watch
 	{
+		protected ushort _previous;
+
 		public WordWatch(MemoryDomain domain, int address)
 		{
 			_domain = domain;
 			_address = address;
+			_previous = GetWord();
 		}
 
 		public override int? Value
@@ -576,6 +606,21 @@ namespace BizHawk.MultiClient
 			get { return GetWord(); }
 		}
 
+		public override int? Previous
+		{
+			get { return _previous; }
+		}
+
+		public override string PreviousStr
+		{
+			get { return FormatValue(_previous); }
+		}
+
+		public override void ResetPrevious()
+		{
+			_previous = GetWord();
+		}
+
 		public override WatchSize Size
 		{
 			get { return WatchSize.Word; }
@@ -688,16 +733,15 @@ namespace BizHawk.MultiClient
 		}
 	}
 
-	public class DetailedWordWatch : WordWatch, IWatchDetails
+	public sealed class DetailedWordWatch : WordWatch, IWatchDetails
 	{
 		private ushort _value;
-		private ushort _previous;
 
 		public DetailedWordWatch(MemoryDomain domain, int address)
 			: base(domain, address)
 		{
 			Notes = String.Empty;
-			_previous = _value = GetWord();
+			_value = GetWord();
 		}
 
 		public override string ToString()
@@ -708,10 +752,6 @@ namespace BizHawk.MultiClient
 		public int ChangeCount { get; private set; }
 		public void ClearChangeCount() { ChangeCount = 0; }
 
-		public int? Previous { get { return _previous; } }
-		public string PreviousStr { get { return FormatValue(_previous); } }
-		public void ResetPrevious() { _previous = _value; }
-
 		public string Diff
 		{
 			get { return FormatValue((ushort)(_previous - _value)); }
@@ -751,10 +791,13 @@ namespace BizHawk.MultiClient
 
 	public class DWordWatch : Watch
 	{
+		protected uint _previous;
+
 		public DWordWatch(MemoryDomain domain, int address)
 		{
 			_domain = domain;
 			_address = address;
+			_previous = GetDWord();
 		}
 
 		public override int? Value
@@ -762,6 +805,21 @@ namespace BizHawk.MultiClient
 			get { return (int)GetDWord(); }
 		}
 
+		public override int? Previous
+		{
+			get { return (int)_previous; }
+		}
+
+		public override string PreviousStr
+		{
+			get { return FormatValue(_previous); }
+		}
+
+		public override void ResetPrevious()
+		{
+			_previous = GetWord();
+		}
+
 		public override WatchSize Size
 		{
 			get { return WatchSize.DWord; }
@@ -876,16 +934,15 @@ namespace BizHawk.MultiClient
 		}
 	}
 
-	public class DetailedDWordWatch : DWordWatch, IWatchDetails
+	public sealed class DetailedDWordWatch : DWordWatch, IWatchDetails
 	{
 		private uint _value;
-		private uint _previous;
 
 		public DetailedDWordWatch(MemoryDomain domain, int address)
 			: base(domain, address)
 		{
 			Notes = String.Empty;
-			_previous = _value = GetDWord();
+			_value = GetDWord();
 		}
 
 		public override string ToString()
@@ -895,10 +952,6 @@ namespace BizHawk.MultiClient
 		public int ChangeCount { get; private set; }
 		public void ClearChangeCount() { ChangeCount = 0; }
 
-		public int? Previous { get { return (int)_previous; } }
-		public string PreviousStr { get { return FormatValue(_previous); } }
-		public void ResetPrevious() { _previous = _value; }
-
 		public string Diff
 		{
 			get { return FormatValue(_previous - _value); }
diff --git a/BizHawk.MultiClient/tools/Watch/WatchList.cs b/BizHawk.MultiClient/tools/Watch/WatchList.cs
index 2863c7eb66..d2d3b999b3 100644
--- a/BizHawk.MultiClient/tools/Watch/WatchList.cs
+++ b/BizHawk.MultiClient/tools/Watch/WatchList.cs
@@ -117,7 +117,7 @@ namespace BizHawk.MultiClient
 					if (reverse)
 					{
 						_watchList = _watchList
-							.OrderByDescending(x => (x as IWatchDetails).PreviousStr)
+							.OrderByDescending(x => x.PreviousStr)
 							.ThenBy(x => x.Address ?? 0)
 							.ThenBy(x => x.Size)
 							.ThenBy(x => x.Type)
@@ -126,7 +126,7 @@ namespace BizHawk.MultiClient
 					else
 					{
 						_watchList = _watchList
-							.OrderBy(x => (x as IWatchDetails).PreviousStr)
+							.OrderBy(x => x.PreviousStr)
 							.ThenBy(x => x.Address ?? 0)
 							.ThenBy(x => x.Size)
 							.ThenBy(x => x.Type)