diff --git a/crates/loro-core/benches/text.rs b/crates/loro-core/benches/text.rs
index c0a8346b..52afa986 100644
--- a/crates/loro-core/benches/text.rs
+++ b/crates/loro-core/benches/text.rs
@@ -15,7 +15,7 @@ mod run {
     use rand::SeedableRng;
     use serde_json::Value;
 
-    pub fn criterion_benchmark(c: &mut Criterion) {
+    pub fn two_client_edits(c: &mut Criterion) {
         let mut rgn = rand::rngs::StdRng::seed_from_u64(0);
         let mut bytes = Vec::new();
         for _ in 0..1000 {
@@ -27,6 +27,10 @@ mod run {
         c.bench_function("random text edit 2 sites", |b| {
             b.iter(|| test_multi_sites(2, actions.clone().into()))
         });
+
+        c.bench_function("random text edit 8 sites", |b| {
+            b.iter(|| test_multi_sites(8, actions.clone().into()))
+        });
     }
 
     pub fn b4(c: &mut Criterion) {
@@ -35,6 +39,7 @@ mod run {
         d.read_to_string(&mut s).unwrap();
         let json: Value = serde_json::from_str(&s).unwrap();
         let txns = json.as_object().unwrap().get("txns");
+        println!("{}", txns.unwrap().as_array().unwrap().len());
         c.bench_function("B4", |b| {
             b.iter(|| {
                 let mut loro = LoroCore::default();
@@ -57,12 +62,41 @@ mod run {
                 }
             })
         });
+
+        let mut b = c.benchmark_group("sync");
+        b.sample_size(10);
+        b.bench_function("B4Sync", |b| {
+            b.iter(|| {
+                let mut loro = LoroCore::default();
+                let mut loro_b = LoroCore::default();
+                for txn in txns.unwrap().as_array().unwrap() {
+                    let mut text = loro.get_or_create_root_text("text").unwrap();
+                    let patches = txn
+                        .as_object()
+                        .unwrap()
+                        .get("patches")
+                        .unwrap()
+                        .as_array()
+                        .unwrap();
+                    for patch in patches {
+                        let pos = patch[0].as_u64().unwrap() as usize;
+                        let del_here = patch[1].as_u64().unwrap() as usize;
+                        let ins_content = patch[2].as_str().unwrap();
+                        text.delete(pos, del_here);
+                        text.insert(pos, ins_content);
+                    }
+
+                    drop(text);
+                    loro_b.import(loro.export(loro_b.vv()));
+                }
+            })
+        });
     }
 }
 pub fn dumb(_c: &mut Criterion) {}
 
 #[cfg(feature = "fuzzing")]
-criterion_group!(benches, run::criterion_benchmark, run::b4);
+criterion_group!(benches, run::two_client_edits, run::b4);
 #[cfg(not(feature = "fuzzing"))]
 criterion_group!(benches, dumb);
 criterion_main!(benches);
diff --git a/crates/loro-core/examples/text_sync.rs b/crates/loro-core/examples/text_sync.rs
new file mode 100644
index 00000000..72f14b22
--- /dev/null
+++ b/crates/loro-core/examples/text_sync.rs
@@ -0,0 +1,42 @@
+#[cfg(not(feature = "fuzzing"))]
+fn main() {}
+
+#[cfg(feature = "fuzzing")]
+fn main() {
+    const RAW_DATA: &[u8; 901823] = include_bytes!("../benches/automerge-paper.json.gz");
+    use std::io::Read;
+
+    use flate2::read::GzDecoder;
+    use loro_core::LoroCore;
+    use serde_json::Value;
+
+    let mut d = GzDecoder::new(&RAW_DATA[..]);
+    let mut s = String::new();
+    d.read_to_string(&mut s).unwrap();
+    let json: Value = serde_json::from_str(&s).unwrap();
+    let txns = json.as_object().unwrap().get("txns");
+    println!("Txn: {}", txns.unwrap().as_array().unwrap().len());
+
+    let mut loro = LoroCore::default();
+    let mut loro_b = LoroCore::default();
+    for txn in txns.unwrap().as_array().unwrap() {
+        let mut text = loro.get_or_create_root_text("text").unwrap();
+        let patches = txn
+            .as_object()
+            .unwrap()
+            .get("patches")
+            .unwrap()
+            .as_array()
+            .unwrap();
+        for patch in patches {
+            let pos = patch[0].as_u64().unwrap() as usize;
+            let del_here = patch[1].as_u64().unwrap() as usize;
+            let ins_content = patch[2].as_str().unwrap();
+            text.delete(pos, del_here);
+            text.insert(pos, ins_content);
+        }
+
+        drop(text);
+        loro_b.import(loro.export(loro_b.vv()));
+    }
+}
diff --git a/crates/loro-core/justfile b/crates/loro-core/justfile
index a8de5b87..14abc1c5 100644
--- a/crates/loro-core/justfile
+++ b/crates/loro-core/justfile
@@ -25,7 +25,7 @@ quick-fuzz:
   cargo fuzz run text -- -max_total_time=10 -max_len=1000
 
 flame:
-  cargo flamegraph --example test --features=fuzzing --root
+  cargo flamegraph --example text_sync --features=fuzzing --root
 
 bench *FLAGS:
   cargo bench --features fuzzing {{FLAGS}}
diff --git a/crates/loro-core/src/dag.rs b/crates/loro-core/src/dag.rs
index 343e647d..a18acfdf 100644
--- a/crates/loro-core/src/dag.rs
+++ b/crates/loro-core/src/dag.rs
@@ -26,7 +26,7 @@ use crate::{
     change::Lamport,
     debug_log,
     id::{ClientID, Counter, ID},
-    span::{HasId, HasIdSpan, HasLamport, HasLamportSpan, IdSpan},
+    span::{CounterSpan, HasId, HasIdSpan, HasLamport, HasLamportSpan, IdSpan},
     version::{IdSpanVector, VersionVector, VersionVectorDiff},
 };
 
@@ -111,6 +111,29 @@ impl<T: Dag + ?Sized> DagUtils for T {
         if from == to {
             return ans;
         }
+        if from.len() == 1 && to.len() == 1 {
+            let from = from[0];
+            let to = to[0];
+            if from.client_id == to.client_id {
+                let from_span = self.get(from).unwrap();
+                let to_span = self.get(to).unwrap();
+                if from_span.deps().len() == 1 && to_span.contains_id(from_span.deps()[0]) {
+                    ans.left.insert(
+                        from.client_id,
+                        CounterSpan::new(to.counter + 1, from.counter + 1),
+                    );
+                    return ans;
+                }
+
+                if to_span.deps().len() == 1 && from_span.contains_id(to_span.deps()[0]) {
+                    ans.right.insert(
+                        from.client_id,
+                        CounterSpan::new(from.counter + 1, to.counter + 1),
+                    );
+                    return ans;
+                }
+            }
+        }
 
         _find_common_ancestor(
             &|v| self.get(v),