diff --git a/SabreTools.DatFiles/ItemDictionaryDB.cs b/SabreTools.DatFiles/ItemDictionaryDB.cs
index f6a165b4..3c97083e 100644
--- a/SabreTools.DatFiles/ItemDictionaryDB.cs
+++ b/SabreTools.DatFiles/ItemDictionaryDB.cs
@@ -500,6 +500,76 @@ namespace SabreTools.DatFiles
             }
         }
 
+        /// <summary>
+        /// List all duplicates found in a DAT based on a DatItem
+        /// </summary>
+        /// <param name="datItem">Item to try to match</param>
+        /// <param name="sorted">True if the DAT is already sorted accordingly, false otherwise (default)</param>
+        /// <returns>List of matched DatItem objects</returns>
+        public ConcurrentList<(long, DatItem)> GetDuplicates(DatItem datItem, bool sorted = false)
+        {
+            ConcurrentList<(long, DatItem)> output = [];
+
+            // Check for an empty rom list first
+            if (DatStatistics.TotalCount == 0)
+                return output;
+
+            // We want to get the proper key for the DatItem
+            string key = SortAndGetKey(datItem, sorted);
+
+            // If the key doesn't exist, return the empty list
+            var roms = GetDatItemsForBucket(key);
+            if (roms == null || roms.Length == 0)
+                return output;
+
+            // Try to find duplicates
+            ConcurrentList<(long, DatItem)> left = [];
+            for (int i = 0; i < roms.Length; i++)
+            {
+                DatItem other = roms[i].Item2;
+                if (other.GetBoolFieldValue(DatItem.RemoveKey) == true)
+                    continue;
+
+                if (datItem.Equals(other))
+                {
+                    other.SetFieldValue<bool?>(DatItem.RemoveKey, true);
+                    output.Add(other);
+                }
+                else
+                {
+                    left.Add(other);
+                }
+            }
+
+            // Add back all roms with the proper flags
+            _buckets[key] = output.Concat(left).Select(i => i.Item1).ToConcurrentList();
+            return output;
+        }
+
+        /// <summary>
+        /// Check if a DAT contains the given DatItem
+        /// </summary>
+        /// <param name="datItem">Item to try to match</param>
+        /// <param name="sorted">True if the DAT is already sorted accordingly, false otherwise (default)</param>
+        /// <returns>True if it contains the rom, false otherwise</returns>
+        public bool HasDuplicates(DatItem datItem, bool sorted = false)
+        {
+            // Check for an empty rom list first
+            if (DatStatistics.TotalCount == 0)
+                return false;
+
+            // We want to get the proper key for the DatItem
+            string key = SortAndGetKey(datItem, sorted);
+
+            // If the key doesn't exist
+            var roms = GetDatItemsForBucket(key);
+            if (roms == null || roms.Length == 0)
+                return false;
+
+            // Try to find duplicates
+            return roms.Any(r => datItem.Equals(r.Item2)) == true;
+        }
+
         /// <summary>
         /// Merge an arbitrary set of item pairs based on the supplied information
         /// </summary>
@@ -620,6 +690,42 @@ namespace SabreTools.DatFiles
             return output;
         }
 
+        /// <summary>
+        /// Get the highest-order Field value that represents the statistics
+        /// </summary>
+        private ItemKey GetBestAvailable()
+        {
+            // Get the required counts
+            long diskCount = DatStatistics.GetItemCount(ItemType.Disk);
+            long mediaCount = DatStatistics.GetItemCount(ItemType.Media);
+            long romCount = DatStatistics.GetItemCount(ItemType.Rom);
+            long nodumpCount = DatStatistics.GetStatusCount(ItemStatus.Nodump);
+
+            // If all items are supposed to have a SHA-512, we bucket by that
+            if (diskCount + mediaCount + romCount - nodumpCount == DatStatistics.GetHashCount(HashType.SHA512))
+                return ItemKey.SHA512;
+
+            // If all items are supposed to have a SHA-384, we bucket by that
+            else if (diskCount + mediaCount + romCount - nodumpCount == DatStatistics.GetHashCount(HashType.SHA384))
+                return ItemKey.SHA384;
+
+            // If all items are supposed to have a SHA-256, we bucket by that
+            else if (diskCount + mediaCount + romCount - nodumpCount == DatStatistics.GetHashCount(HashType.SHA256))
+                return ItemKey.SHA256;
+
+            // If all items are supposed to have a SHA-1, we bucket by that
+            else if (diskCount + mediaCount + romCount - nodumpCount == DatStatistics.GetHashCount(HashType.SHA1))
+                return ItemKey.SHA1;
+
+            // If all items are supposed to have a MD5, we bucket by that
+            else if (diskCount + mediaCount + romCount - nodumpCount == DatStatistics.GetHashCount(HashType.MD5))
+                return ItemKey.MD5;
+
+            // Otherwise, we bucket by CRC
+            else
+                return ItemKey.CRC;
+        }
+
         /// <summary>
         /// Get the bucketing key for a given item index
         /// <param name="itemIndex">Index of the current item</param>
@@ -916,6 +1022,22 @@ namespace SabreTools.DatFiles
             return true;
         }
 
+        /// <summary>
+        /// Sort the input DAT and get the key to be used by the item
+        /// </summary>
+        /// <param name="datItem">Item to try to match</param>
+        /// <param name="sorted">True if the DAT is already sorted accordingly, false otherwise (default)</param>
+        /// <returns>Key to try to use</returns>
+        private string SortAndGetKey(DatItem datItem, bool sorted = false)
+        {
+            // If we're not already sorted, take care of it
+            if (!sorted)
+                BucketBy(GetBestAvailable(), DedupeType.None);
+
+            // Now that we have the sorted type, we get the proper key
+            return datItem.GetKey(_bucketedBy);
+        }
+
         #endregion
 
         #region Filtering
diff --git a/SabreTools.DatTools/Verification.cs b/SabreTools.DatTools/Verification.cs
index 18124561..6a84a9b4 100644
--- a/SabreTools.DatTools/Verification.cs
+++ b/SabreTools.DatTools/Verification.cs
@@ -108,6 +108,90 @@ namespace SabreTools.DatTools
             datFile.Header.SetFieldValue<string?>(Models.Metadata.Header.NameKey, $"fixDAT_{datFile.Header.GetStringFieldValue(Models.Metadata.Header.NameKey)}");
             datFile.Header.SetFieldValue<string?>(Models.Metadata.Header.DescriptionKey, $"fixDAT_{datFile.Header.GetStringFieldValue(Models.Metadata.Header.DescriptionKey)}");
             datFile.Items.ClearMarked();
+
+            return success;
+        }
+
+        /// <summary>
+        /// Verify a DatFile against a set of depots, leaving only missing files
+        /// </summary>
+        /// <param name="datFile">Current DatFile object to verify against</param>
+        /// <param name="inputs">List of input directories to compare against</param>
+        /// <returns>True if verification was a success, false otherwise</returns>
+        public static bool VerifyDepotDB(DatFile datFile, List<string> inputs)
+        {
+            bool success = true;
+
+            var watch = new InternalStopwatch("Verifying all from supplied depots");
+
+            // Now loop through and get only directories from the input paths
+            List<string> directories = [];
+            foreach (string input in inputs)
+            {
+                // Add to the list if the input is a directory
+                if (Directory.Exists(input))
+                {
+                    logger.Verbose($"Adding depot: {input}");
+                    directories.Add(input);
+                }
+            }
+
+            // If we don't have any directories, we want to exit
+            if (directories.Count == 0)
+                return success;
+
+            // Now that we have a list of depots, we want to bucket the input DAT by SHA-1
+            datFile.ItemsDB.BucketBy(ItemKey.SHA1, DedupeType.None);
+
+            // Then we want to loop through each of the hashes and see if we can rebuild
+            var keys = datFile.ItemsDB.SortedKeys.ToList();
+            foreach (string hash in keys)
+            {
+                // Pre-empt any issues that could arise from string length
+                if (hash.Length != Constants.SHA1Length)
+                    continue;
+
+                logger.User($"Checking hash '{hash}'");
+
+                // Get the extension path for the hash
+                string? subpath = Utilities.GetDepotPath(hash, datFile.Header.GetFieldValue<DepotInformation?>(DatHeader.InputDepotKey)?.Depth ?? 0);
+                if (subpath == null)
+                    continue;
+
+                // Find the first depot that includes the hash
+                string? foundpath = null;
+                foreach (string directory in directories)
+                {
+                    if (System.IO.File.Exists(Path.Combine(directory, subpath)))
+                    {
+                        foundpath = Path.Combine(directory, subpath);
+                        break;
+                    }
+                }
+
+                // If we didn't find a path, then we continue
+                if (foundpath == null)
+                    continue;
+
+                // If we have a path, we want to try to get the rom information
+                GZipArchive tgz = new(foundpath);
+                BaseFile? fileinfo = tgz.GetTorrentGZFileInfo();
+
+                // If the file information is null, then we continue
+                if (fileinfo == null)
+                    continue;
+
+                // Now we want to remove all duplicates from the DAT
+                datFile.ItemsDB.GetDuplicates(new Rom(fileinfo))
+                    .AddRange(datFile.ItemsDB.GetDuplicates(new Disk(fileinfo)));
+            }
+
+            watch.Stop();
+
+            // Set fixdat headers in case of writing out
+            datFile.Header.SetFieldValue<string?>(DatHeader.FileNameKey, $"fixDAT_{datFile.Header.GetStringFieldValue(DatHeader.FileNameKey)}");
+            datFile.Header.SetFieldValue<string?>(Models.Metadata.Header.NameKey, $"fixDAT_{datFile.Header.GetStringFieldValue(Models.Metadata.Header.NameKey)}");
+            datFile.Header.SetFieldValue<string?>(Models.Metadata.Header.DescriptionKey, $"fixDAT_{datFile.Header.GetStringFieldValue(Models.Metadata.Header.DescriptionKey)}");
             datFile.ItemsDB.ClearMarked();
 
             return success;
@@ -158,6 +242,50 @@ namespace SabreTools.DatTools
             datFile.Header.SetFieldValue<string?>(Models.Metadata.Header.NameKey, $"fixDAT_{datFile.Header.GetStringFieldValue(Models.Metadata.Header.NameKey)}");
             datFile.Header.SetFieldValue<string?>(Models.Metadata.Header.DescriptionKey, $"fixDAT_{datFile.Header.GetStringFieldValue(Models.Metadata.Header.DescriptionKey)}");
             datFile.Items.ClearMarked();
+
+            return success;
+        }
+
+        /// <summary>
+        /// Verify a DatFile against a set of inputs, leaving only missing files
+        /// </summary>
+        /// <param name="datFile">Current DatFile object to verify against</param>
+        /// <param name="hashOnly">True if only hashes should be checked, false for full file information</param>
+        /// <returns>True if verification was a success, false otherwise</returns>
+        public static bool VerifyGenericDB(DatFile datFile, bool hashOnly)
+        {
+            bool success = true;
+
+            var watch = new InternalStopwatch("Verifying all from supplied paths");
+
+            // Force bucketing according to the flags
+            if (hashOnly)
+                datFile.ItemsDB.BucketBy(ItemKey.CRC, DedupeType.Full);
+            else
+                datFile.ItemsDB.BucketBy(ItemKey.Machine, DedupeType.Full);
+
+            // Then mark items for removal
+            var keys = datFile.ItemsDB.SortedKeys.ToList();
+            foreach (string key in keys)
+            {
+                var items = datFile.ItemsDB.GetDatItemsForBucket(key);
+                if (items == null)
+                    continue;
+
+                for (int i = 0; i < items.Length; i++)
+                {
+                    // Unmatched items will have a source ID of int.MaxValue, remove all others
+                    if (items[i].Item2.GetFieldValue<Source?>(DatItem.SourceKey)?.Index != int.MaxValue)
+                        items[i].Item2.SetFieldValue<bool?>(DatItem.RemoveKey, true);
+                }
+            }
+
+            watch.Stop();
+
+            // Set fixdat headers in case of writing out
+            datFile.Header.SetFieldValue<string?>(DatHeader.FileNameKey, $"fixDAT_{datFile.Header.GetStringFieldValue(DatHeader.FileNameKey)}");
+            datFile.Header.SetFieldValue<string?>(Models.Metadata.Header.NameKey, $"fixDAT_{datFile.Header.GetStringFieldValue(Models.Metadata.Header.NameKey)}");
+            datFile.Header.SetFieldValue<string?>(Models.Metadata.Header.DescriptionKey, $"fixDAT_{datFile.Header.GetStringFieldValue(Models.Metadata.Header.DescriptionKey)}");
             datFile.ItemsDB.ClearMarked();
 
             return success;
diff --git a/SabreTools.DatTools/Writer.cs b/SabreTools.DatTools/Writer.cs
index eefc96f5..586e5f99 100644
--- a/SabreTools.DatTools/Writer.cs
+++ b/SabreTools.DatTools/Writer.cs
@@ -69,9 +69,11 @@ namespace SabreTools.DatTools
 
             // Bucket roms by game name, if not already
             datFile.Items.BucketBy(ItemKey.Machine, DedupeType.None);
+            datFile.ItemsDB.BucketBy(ItemKey.Machine, DedupeType.None);
 
             // Output the number of items we're going to be writing
             logger.User($"A total of {datFile.Items.DatStatistics.TotalCount - datFile.Items.DatStatistics.RemovedCount} items will be written out to '{datFile.Header.GetStringFieldValue(DatHeader.FileNameKey)}'");
+            //logger.User($"A total of {datFile.ItemsDB.DatStatistics.TotalCount - datFile.ItemsDB.DatStatistics.RemovedCount} items will be written out to '{datFile.Header.GetStringFieldValue(DatHeader.FileNameKey)}'");
 
             // Get the outfile names
             Dictionary<DatFormat, string> outfiles = datFile.Header.CreateOutFileNames(outDir!, overwrite);
@@ -128,15 +130,28 @@ namespace SabreTools.DatTools
             if (diskCount + mediaCount + romCount == 0)
                 datFile.Items.RecalculateStats();
 
+            diskCount = datFile.ItemsDB.DatStatistics.GetItemCount(ItemType.Disk);
+            mediaCount = datFile.ItemsDB.DatStatistics.GetItemCount(ItemType.Media);
+            romCount = datFile.ItemsDB.DatStatistics.GetItemCount(ItemType.Rom);
+
+            if (diskCount + mediaCount + romCount == 0)
+                datFile.ItemsDB.RecalculateStats();
+
             datFile.Items.BucketBy(ItemKey.Machine, DedupeType.None, norename: true);
+            datFile.ItemsDB.BucketBy(ItemKey.Machine, DedupeType.None, norename: true);
 
             datFile.Items.DatStatistics.DisplayName = datFile.Header.GetStringFieldValue(DatHeader.FileNameKey);
             datFile.Items.DatStatistics.MachineCount = datFile.Items.Keys.Count;
             datFile.Items.DatStatistics.IsDirectory = false;
 
+            datFile.ItemsDB.DatStatistics.DisplayName = datFile.Header.GetStringFieldValue(DatHeader.FileNameKey);
+            datFile.ItemsDB.DatStatistics.MachineCount = datFile.Items.Keys.Count;
+            datFile.ItemsDB.DatStatistics.IsDirectory = false;
+
             var statsList = new List<DatStatistics>
             {
                 datFile.Items.DatStatistics,
+                //datFile.ItemsDB.DatStatistics,
             };
             var consoleOutput = BaseReport.Create(StatReportFormat.None, statsList);
             consoleOutput!.WriteToFile(null, true, true);
@@ -206,14 +221,19 @@ namespace SabreTools.DatTools
         {
             // Force a statistics recheck, just in case
             datFile.Items.RecalculateStats();
+            datFile.ItemsDB.RecalculateStats();
 
             // If there's nothing there, abort
             if (datFile.Items.DatStatistics.TotalCount == 0)
                 return false;
+            if (datFile.ItemsDB.DatStatistics.TotalCount == 0)
+                return false;
 
             // If every item is removed, abort
             if (datFile.Items.DatStatistics.TotalCount == datFile.Items.DatStatistics.RemovedCount)
                 return false;
+            if (datFile.ItemsDB.DatStatistics.TotalCount == datFile.ItemsDB.DatStatistics.RemovedCount)
+                return false;
 
             return true;
         }
diff --git a/SabreTools/Features/Verify.cs b/SabreTools/Features/Verify.cs
index 4b2c3694..9f1cc4bf 100644
--- a/SabreTools/Features/Verify.cs
+++ b/SabreTools/Features/Verify.cs
@@ -94,6 +94,7 @@ namespace SabreTools.Features
                         }
 
                         Verification.VerifyGeneric(datdata, hashOnly);
+                        //Verification.VerifyGenericDB(datdata, hashOnly);
                     }
 
                     // Now write out if there are any items left
@@ -145,6 +146,7 @@ namespace SabreTools.Features
                     }
 
                     Verification.VerifyGeneric(datdata, hashOnly);
+                    //Verification.VerifyGenericDB(datdata, hashOnly);
                 }
 
                 // Now write out if there are any items left