diff --git a/git-features/src/parallel.rs b/git-features/src/parallel.rs
index df445ee4f60..24f628b45a5 100644
--- a/git-features/src/parallel.rs
+++ b/git-features/src/parallel.rs
@@ -3,7 +3,7 @@ pub trait Reducer {
     type Output;
     type Error;
     fn feed(&mut self, input: Self::Input) -> Result<(), Self::Error>;
-    fn finalize(&mut self) -> Result<Self::Output, Self::Error>;
+    fn finalize(self) -> Result<Self::Output, Self::Error>;
 }
 
 mod serial {
diff --git a/git-odb/src/pack/file/read.rs b/git-odb/src/pack/file/read.rs
index c8f69f34551..7fbaace64c6 100644
--- a/git-odb/src/pack/file/read.rs
+++ b/git-odb/src/pack/file/read.rs
@@ -17,13 +17,13 @@ struct Delta {
     data_offset: u64,
 }
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Eq, Hash, Ord, PartialOrd, Clone)]
 pub enum ResolvedBase {
     InPack(Entry),
     OutOfPack { kind: object::Kind, end: usize },
 }
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, PartialEq, Eq, Hash, Ord, PartialOrd, Clone)]
 pub struct DecodeEntryResult {
     pub kind: object::Kind,
     pub num_deltas: u32,
diff --git a/git-odb/src/pack/index/verify.rs b/git-odb/src/pack/index/verify.rs
index 3456f30d763..bc0f387646e 100644
--- a/git-odb/src/pack/index/verify.rs
+++ b/git-odb/src/pack/index/verify.rs
@@ -3,6 +3,7 @@ use crate::{pack, pack::index};
 use git_features::progress::{self, Progress};
 use git_object::SHA1_SIZE;
 use quick_error::quick_error;
+use smallvec::alloc::collections::BTreeMap;
 use std::time::Instant;
 
 quick_error! {
@@ -59,6 +60,14 @@ impl Into<String> for TimeThroughput {
     }
 }
 
+#[derive(Debug, PartialEq, Eq, Hash, Ord, PartialOrd, Clone)]
+pub struct FileChecksumResult {
+    /// The sha1 over the whole index file
+    id: git_object::Id,
+    average: DecodeEntryResult,
+    objects_per_chain_length: BTreeMap<u32, u32>,
+}
+
 /// Methods to verify and validate the content of the index file
 impl index::File {
     pub fn checksum_of_index(&self) -> git_object::Id {
@@ -133,40 +142,34 @@ impl index::File {
 
                 fn add_decode_result(
                     DecodeEntryResult {
-                        kind,
-                        num_deltas,
-                        decompressed_size,
-                        compressed_size,
-                        object_size,
-                    }: DecodeEntryResult,
+                        kind: _,
+                        mut num_deltas,
+                        mut decompressed_size,
+                        mut compressed_size,
+                        mut object_size,
+                    }: &mut DecodeEntryResult,
                     rhs: DecodeEntryResult,
-                ) -> DecodeEntryResult {
-                    DecodeEntryResult {
-                        kind,
-                        num_deltas: num_deltas + rhs.num_deltas,
-                        decompressed_size: decompressed_size + rhs.decompressed_size,
-                        compressed_size: compressed_size + rhs.compressed_size,
-                        object_size: object_size + rhs.object_size,
-                    }
+                ) {
+                    num_deltas += rhs.num_deltas;
+                    decompressed_size += rhs.decompressed_size;
+                    compressed_size += rhs.compressed_size;
+                    object_size += rhs.object_size;
                 }
 
                 fn div_decode_result(
                     DecodeEntryResult {
-                        kind,
-                        num_deltas,
-                        decompressed_size,
-                        compressed_size,
-                        object_size,
-                    }: DecodeEntryResult,
+                        kind: _,
+                        mut num_deltas,
+                        mut decompressed_size,
+                        mut compressed_size,
+                        mut object_size,
+                    }: &mut DecodeEntryResult,
                     div: usize,
-                ) -> DecodeEntryResult {
-                    DecodeEntryResult {
-                        kind,
-                        num_deltas: num_deltas / div as u32,
-                        decompressed_size: decompressed_size / div as u64,
-                        compressed_size: compressed_size / div,
-                        object_size: object_size / div as u64,
-                    }
+                ) {
+                    num_deltas /= div as u32;
+                    decompressed_size /= div as u64;
+                    compressed_size /= div;
+                    object_size /= div as u64;
                 }
 
                 struct Reducer<'a, P> {
@@ -189,14 +192,15 @@ impl index::File {
                         self.entries_seen += num_entries as u32;
                         self.chunks_seen += 1;
 
-                        self.stats = add_decode_result(self.stats, chunk_stats);
+                        add_decode_result(&mut self.stats, chunk_stats);
                         self.progress.lock().unwrap().set(self.entries_seen);
                         Ok(())
                     }
 
-                    fn finalize(&mut self) -> Result<Self::Output, Self::Error> {
+                    fn finalize(mut self) -> Result<Self::Output, Self::Error> {
                         self.progress.lock().unwrap().done("finished");
-                        Ok(div_decode_result(self.stats, self.chunks_seen))
+                        div_decode_result(&mut self.stats, self.chunks_seen);
+                        Ok(self.stats)
                     }
                 }
 
@@ -256,7 +260,7 @@ impl index::File {
                                 })?;
                             let object_kind = entry_stats.kind;
                             let consumed_input = entry_stats.compressed_size;
-                            stats = add_decode_result(stats, entry_stats);
+                            add_decode_result(&mut stats, entry_stats);
 
                             let mut header_buf = [0u8; 64];
                             let header_size = crate::loose::db::serde::write_header(
@@ -294,7 +298,7 @@ impl index::File {
                             }
                             progress.set(idx as u32);
                         }
-                        stats = div_decode_result(stats, entries.len());
+                        div_decode_result(&mut stats, entries.len());
                         Ok((entries.len(), stats))
                     },
                     Reducer {
diff --git a/src/plumbing/lean.rs b/src/plumbing/lean.rs
index 266b7e527df..36c4664a857 100644
--- a/src/plumbing/lean.rs
+++ b/src/plumbing/lean.rs
@@ -19,6 +19,9 @@ mod options {
     #[derive(FromArgs, PartialEq, Debug)]
     #[argh(subcommand, name = "verify-pack")]
     pub struct VerifyPack {
+        /// if set, output statistical information about the pack
+        #[argh(switch, short = 's')]
+        pub statistics: bool,
         /// if set, verbose progress messages are printed line by line
         #[argh(switch, short = 'v')]
         pub verbose: bool,
@@ -37,7 +40,11 @@ pub fn main() -> Result<()> {
     pub use options::*;
     let cli: Args = argh::from_env();
     match cli.subcommand {
-        SubCommands::VerifyPack(VerifyPack { path, verbose }) => {
+        SubCommands::VerifyPack(VerifyPack {
+            path,
+            verbose,
+            statistics,
+        }) => {
             super::init_env_logger(verbose);
             core::verify_pack_or_pack_index(
                 path,